I bought a 12 year old house and there was a small amount of mould in the bathroom. The large housebuilder had fitted a mains ceiling fan on the opposite side of the wall to the bath. It made a noise but would not hold a single sheet of toilet paper up with its suction, I kid you not. Looked in the loft and "ducting" to a roof vent was made of various leftover bits including a flexible toilet connector taped together! Got a Manrose MF100T, put the vent right above the shower and it's been great. Now a flattened toilet roll tube can be held up by the fan, and that's on medium setting!
Guys... you guys have my subscription. You guys are the only ones i have found on youtube that actually get it, and understand the importance of a video WITH A TEST COURSE. The real people out here are interested in retaining the information, not just passively watching youtube videos and forgetting about it a week later.
Very few people want to pay for adequate ventilation in my experience. I've known people who had fairly large and expensive 'luxury' bathrooms installed, but want to use the cheapest fan possible - using the existing ducting or core hole to save a few quid. If there's a loft space above, its fairly easy to install a 4 or 5 inch inline fan and extract via a soffit in many cases. If the fan is mounted above the insulation, they can be extremely quiet - all you hear is the sound of air air being pulled through the inlet grille. If you use a 5" grille, 5" ducting and have the fan set to the lower speed, it can be almost silent, but still retains a very good extraction rate. Having to core a hole through a wall, get up a ladder outside to mount a grille, run sensible dusting etc can take up the best part of a day in some cases. Including the cost of an adequate fan, insulated ducting, install an accessible isolator etc. may well cost £400, but is generally money well spent IMO. When a customer says they want to use the existing fan in their nice newly fitted bathroom - just because it seems to work and saves some money I despair! If a fan wont even hold a single sheet of toilet paper to the ceiling/wall inlet, then you know its not going to perform very well! Humidistat fans can cause grief in certain properties. We retrofitted one in a basement in Kensington and would run constantly no matter what humidity sensitivity it was set to - purely as the basement had high humidity all year round due to damp issues.
I gave up on standard extractors and instead fitted two in-line fans in the loft. They simply amazing, and have (especially in the bathroom) completely eliminated shower condensation.
@@barryfoster453 What are you a qualified "engineer" in? Civil, electrical, mechanical? I'm a spark, I ain't going to touch gas or pouring concrete. Your 49 years of experience means nothing at all if it isn't in the right field. It's really difficult to check if you have sufficient ventilation in a roof space, because you can't test the static pressure accurately. Sure, it 'might' work. I actually care about the quality of my work so I want to be sure.
What lot of people fail to understand is that you can put hundred extractor in your romm, if there is no way for the air to enter from an other way, there will be no extraction because the room will be in depression and the air flow will stop.
There will be some not a lot I clearly said no most bath rooms have a door with gaps in hundreds of fans in a small bathroom will create passive pressure drawing airbon though the door is gaps and any key hole, not a lot but enough to clearly make your statement of no air flow wrong even one drop of snow at a single walearher station. Is enough for a betting company to be legally obliged to pay up a white Christmas bet,
What's not been mentioned here (directly) is that most of the types of fan shown (I can't for the EnviroVent models) are not suitable for use in fully ducted systems. If you have the space, i.e., can fit the fan in the loft, a high pressure duct fan is a far better option. Also, if using ducting, it's best to use insulated ducting to reduce condensate formation in the ductwork.
@@mikepeter1323 also when there is no makeup air you start pulling in air from places you don’t want to like around lighting, closed windows, electrical outlets and this in turn will bring with it the dust from insulation and other contaminants that you don’t want. You could also be pulling in un-conditioned air and expelling the conditioned air that you paid to cool or heat which is a kick in the wallet lol. Same happens with unbalanced hvac systems!.
I think it is important to note that the different performance of fans is not just due to quality differences. The type of fan design usually matters the most. There are different fundamental designs optimized for high flow, high pressure, or a bit of both - but you inherrently can't be great at both. The design of fanblades is a very well explored science, so don't let marketing persuade you that some expensive fancy fan has the best of both worlds. This is a design tradeoff you have to maks - so use the appropriate type for the spesific situation. High flow fans typically have fewer, larger and more spaced blades with deep angling to scoop up a lot of air, but they work best if you are venting sirectly to the outside with no or minimal ducting. They drop in performance very quickly if there are restrictions and might even stall out completely if used inappropriately. High pressure fans have many, dense, shallow-angle blades to maximize pressure (ie. how well it can force air to move against restrictions, like long ducting or filters). While every fan will lose performance with long and winding ducting, these will suffer least. Personally I would go for a model with an adjustable hygrostat (humidity meter/controller). These sensors are cheap and shouldnt add much cost, but it can can save both noise and energy by running on minimum or even turning off when the room is already dry. Remember that in the winter you are venting out the heat in the house, so you don't want excessive venting when its not needed. Having a "boost" button that temporarily runs the fan full speed can be nice if you want to get rid of toilet stinks quickly. Thats also a common feature.
In my opinion, it's actually best to go for a Heat Recovery Fan which is on all the time. Many have a boost feature which you can activate while you're in the bathroom.
@@barryfoster453 full house it's a unit made by vent axia sits in attic has inlet and outlet to the roof and every room has a vent to it via a manifold for both extraction and fresh air from outside
@@barryfoster453 it's a vent axia system it uses a rigid ducting its only feasible in renovations or new builds it would be hard to retrofit to a house without destroying every room
I ended up simply installing a PIR unit onto my envirovent 100 and it drastically improved the extraction process overall, stink humidity etc with a run on timer, along with ensuring a 10mm gap under the door.
When I fit inline fans and ducting, I put the fan as close to the outside vent as I can. Less pressure to push against and let the power of atmospheric pressure fill the slight vacuum behind.
The position of the fan is irrelevant. The Total Static Pressure is the sum of the pressure resistance in the duct on either side of the fan. Only use an axial fan as tested here if there is a very short duct run. If the air is to be ducted use a wall mounted centrifugal extract fan or an inline fan. Axial fans make noise and do little else.
@@TomB-o4v That's a bit harsh. Plenty of axial fans are capable. Sure, you want to get the anemometer out to check the extraction. For most domestic settings a centrifugal fan is not necessary (or available). Inline fans are also axial, and can present maintenance issues.
I added 3 flow switches when I rebuilt our bathroom. 1 on the cold feed of the shower, bath and toilet which triggers the fan, 1 to the hot feed to the shower & bath (also triggers the fan, added as redundancy). These are connected to the fan where a lighting circuit would normally be connected to trigger the fan, so it's using the built-in timer that keeps the fan on after the water stops flowing. Lastly, there's one on the hot feed of the shower (triggers the lights in the shower cubicle. This has a custom built electronic timer that keeps the lights on for 6 minutes after the water flow stops). There's a sink in the bathroom, but I intentionally put the flow switches after the sink in the water circuit as there's no need for the fan to come on when just brushing teeth or washing hands. With this setup, the fan only comes on when the shower or bath is running, or if the toilet is flushed. It then stays on for 10 minutes or so after the water flow stops. If we ever need to force the fan to come on, we just turn the bath or shower tap on for a second. If we ever need to force the fan off, we just use the fan switch outside the bathroom. We also have a movement sensor that's controlling the lighting, with a 5 minute delay before it turns off. Simple setup that works a treat and has been reliable for over 10 years.
Great idea and not something I thought of. I simply installed a PIR unit onto the fan with run on timer, as the room gets plenty of light. Granted it comes on when brushing teeth, but ventilation is good no matter what. Chopping 10mm from the bottom of the door also helped greatly.
Yes. I much prefer the idea of an external over-run than the cheap and nasty electronics built into many fans, yet couldn't manage to find a device that closes the contacts for a set period commencing when the switch (flow switch in your case) opens contacts rather than commencing when the contacts close. Since then, I've discovered that Italian domestic wiring LOVES using relays. They often use relays instead of 2 or 3 way light switching, and on stairwells they often use timed relays. Practically ever home has a relay or 3 in its lighting circuits. Looking at the datasheets for "Finder" (other brands are available) _temporizzatore luce scale,_ I learned that these can be set to run exactly as I would have needed for an over-run relay. So this would be an alternative to custom building an electronic timer (though I'd love to see the circuit diagram if you are willing to share it).
Nice presentation, however I mis the notice of the supply of air in a (bath)room. If you want to suck out moist air, you need to to supply fresh air. Next if you live in a area with lots of bugs like 🦟, take a vent with a filter or beter with flow-shutters etc.
These in wall fan bug the ever loving hell out of me also the ability for people to turn them off cause of the noise my mother was terrible for not turning it on before a shower. Just use a decent in-line fan with hard tubing! dont bother manufacturing them crappy ones, and the cost will go down! If the uk routinely adopted the European standard of heat recovery ventilation, then there would be even less of a problem, we are SOOOO far behind it's not even funny. Conduit wireing for easy rewire or additions is another perfect example of how far behind we are. I could go on all night, but i got a whole playlist to catch up on. 👍
If housebuilders cared enough to pay the extra price for MVHR systems I will eat several of my hats. In my experience they will only do it if the council wants them to meet noise/pollution regs. Being near an airport or motorway, etc. The few times I was asked to use solid duct in a roof was when the site manager knew that plot was getting inspected for an award.
Heat recovery ventilation is still pretty rare here in mainland Europe. They are starting to put them in new homes now, partly because of the new and more onerous EU energy label scheme.
Heat recovery ventilation is the “standard” in Europe? Dream on. It’s very rare there. I’m not aware of it being the standard anywhere in the world, even if it’s the ideal in most places.
One additional thing to consider is how well the fan seals the ventilation hole when not in use. Cheap fans often don’t have any closing flaps and even those on the premium fan looked to be quite thin plastic so offer little insulation. Building regs required an extractor to be fitted in our utility room despite there being an external door and no buildup of moisture occurring. In winter it was basically a 4” hole straight through to outside so I ended up having to stuff the fan hole with rockwool to stop the wind blowing in, thus of course defeating the purpose of having a fan fitted that we never used anyway.
We had the silent serie for Some years,3-4.. and we reduced& stopped mould grow in the bathroom. but we still had mould grow in the bedroom. So i changed the silent serie for a vent axia multihome, that Provides us from fresh air 24/7! No more mould in the bedroom since we ventilate 24/7.. 🤞🏻
I tried 3 different fans in my bathroom, cheap or expensive the ones that got the job done were noisy as hell and silent ones weren't pumping for sht. Then I ordered a noname one with a 4-speed inverter motor from taobao. THAT Is what actually solved my problem. Speed 1 is almost inaudible even inside, speed 2 is inaudible from the bordering bedroom even in total silence, speed 3 does a fantastic job of clearing heavy fog and speed 4 can clear out a chemical weapon faster than you can breathe it in.
I’m thinking of installing MANROSE LP150STW 150MM (6") AXIAL KITCHEN EXTRACTOR FAN in my bathroom. It suffers from mould and currently doesn’t have any extractor fan. Very useful video
Great video but you've missed the one item that will trip up any casual fan fitment. They are a controlled fitting under B.Regs ie. Building Control must be notified and latest regs says the installation MUST be tested AS INSTALLED, to show it meets the performance required, by a CERTIFIED professional, and results forwarded to Building Control.
Really! What else are building control going to stick their oar in to next. I’m sure we are all going to die if we don’t have a fan in our bathrooms and it’s thoroughly checked by a well paid fan professional. I’m not renting my property, it’s mine. I own it. If building control did what they should then I wouldn’t be spending huge amounts of money to fix the bodge done by the cowboys that built it. Sadly this is still going on with new builds so it’s not like building control are actually doing anything for the money they cost. Provided it’s safe then it’s nothing to do with building control and they can jog on.
@@davideyres955 I feel like that. We had a wood burning stove, but didn't tell anyone (and it didn't go into a liner, either), and in my bathrooms, I have normal light switches, not pullcords. My house, my rules.
Shop around - www.electricalsonline.co.uk/products/envirovent-sil100t-100mm-ultra-quiet-wc-bathroom-extractor-fan?gad_source=1&gbraid=0AAAAABYQt6LNl7PMIEpZ13qoWgxEYbz46&
LOL! I bought a large radial duct fan that delivers about 80 liters/second at 100 Pa (or 40-45 l at 200 Pa), for like half that. I use it in a sort of reverse configuration when I need som extra ventilation in my apartment - "pushing" in fresh air in from the outside (creating overpressure), then open the vents (going to the air ducts in the house) all the way. That increases the airflow (suction) thru the vents a lot (due to larger the larger static pressure difference). Perfect for cooking - get rid of the fumes quickly without having to deal with grease building up in the fan.
I put 150's in the shower/bath room... A metal insulated duct sorted out the performance issues we were having. Fan runs-on for 15 minutes based on the humidity. And here I was switching the fan off after I had finished showering.....
Placement of extractor fan and and available airflow/ventilation into the bathroom/kitchen is also crucial to maximise fan extraction. A suitable gap must be under the door, or an internal wall or door vent/grille, is needed. An under door gap and door vent would be optimal. If the fan is placed between a window and shower/bath and you open the window, the fan is going to extract the air from the window first, leaving the condensation to travel across before it's extracted. The same applies with door gap/grille/internal wall vent airflow and fan placement. Basically install the fan in the optimal placement for airflow extraction, that prevents condensation from leaving the zone 1 area. If i could, i would draw a diagram to explain and make it easier to understand. Optimal fan placement, zone 1 if door gap/door grille/wall vent is opposite to shower/bath tub, i.e airflow/ventilation on the left of the room and shower/bath on the right of the room, or visa versa. Airflow/ventilation in a bathroom, is crucial to condensation extraction. Without airflow/ventilation, an extractor fan can not do the job it was made for, as it can not extract condensation from an unventilated room. A window trickle vent being open in an airtight bathroom, is not enough, even less so with a bathroom that has external walls. And you'll notice this in colder weather, when condensation is dripping on those external walls. If you have the right extractor fan for the size of your bathroom and you have condensation dripping on the walls, then the extractor fan placement is wrong, or there isn't adequate ventilation, or possibly both. Extractor fans need to be cleaned and ducts checked every 4 months or so. Or if you're in the UK and your bathroom is a cold room, double insulate above in the attic. Use expanding foam to seal any air gaps in the attic above the bathroom i.e. wall plates etc, also make a box from insulation board (Kingspan) and place it over the extractor fan unit in the attic and seal with expanding foam. Double check you have a backdraft for the extraction fan. Another reason for cold external walls, is that people do not seal the tiles to prevent moisture from reaching the plasterboard, as these areas are generally not waterproofed prior to tiling. Tiles are porous, so is grout and over time moisture will make its way to the plasterboard if you have a lot of condensation. So when the temperature drops outside, even the smallest amount of moisture in the plasterboards or in the tiles, will turn those walls into ice buckets.
I've been fitting the cheap 150mm extractor fans in our bathrooms for a few years now (from Screwfix). I don't think the 100mm/4 inch ones standardly specified in UK bathrooms are up to the job on a straight run out of the wall, never mind when coupled with flexi duct. I always run them straight out of the wall using a solid duct too. I don't like the idea of putting them through the ceiling and into the loft, what do you do then when you want a loft extension? Also, since the air has to come in from somewhere, trickle vents open are a must, or something else - not that our homes are air tight enough for it to be an issue generally, there's normally some nice gaps under the bath tub or where pipes come out etc. but it is a consideration.
I went for a quiet fan which I don’t mind running 24/7 if it has to, and connected it to a smart relay so my smart home runs it as long as the humidity is above my set target 👌
Extraction is tricky. I went to the trouble of installing an inline fan for my kitchen and use that instead of the ceiling mounted centrifugal, and replaced half of the flexi hose with rigid; result is much quieter. However, a second inline did not perform much better when installed to extract bathroom (with flexi duct), and generated more noise than the existing centrifugal. Due to constraints of installation (inlines can't be mounted at odd angles), it had to be mounted to the wooden beams above, and a 10mm rubber damping mat was not enough to isolate the noise. It's a perception thing but the greater low frequency energy from above made it feel louder. After watching this I think the bathroom shrouded inlet design is also impeding air flow to make it quieter, so I will remove it.
When fitting a fan with a humidity sensor, never set the sensor to anything below 50% as very often the air will be naturally above this level, a low setting will result in the fan running constantly, generally 75% will be ok.
@@srpacific houses in the UK are generally very cold and inneficient. Power is very expensive (especially in the last few years). Many want to sacrifice poor ventilation for warmth.
I'm one of very few council tenants who don't have so much trouble with damp, and my habit of leaving the windows latched into the „vent“ position is most likely for why. I only close them fully (And still leave the frame vents open) during extreme weather events. 👍 I also engage in the German practice of _Stößluft_ - The act of throwing open all the windows to completely replace all the air in the house (Usually, during mid afternoon when the air is still warm-er) - To freshen the atmosphere before turning on the heating in the evening. It drops the temp by a few degrees (Moot in my case as I can't afford to use the heating anyway) but it really does help get rid of the stale air and may contribute positively to health. 🌬🇩🇪👍
Humidistat fans are good (I have one myself) but the ones I have seen share a basic flaw: they all sense relative (R.H.) and not absolute humidity. If I want to avoid condensation, I need an absolute humidity level (defined in terms of g water/kg dry air) that avoids condensation forming above, say, 14°C. The absolute humidity is in a fixed relationship with the dewpoint (the temperature at which the air reaches 100% R.H.). Absolute humidity can be known using a wet-bulb thermometer as well as a normal thermometer, or, if you have a way of measuring R.H., you can very easily know it from the 'normal' dry-bulb thermometer temperature and the R.H. Relative humidity isn't a very useful thing to monitor in order to control a fan. I could have a bathroom with air at 23°C and 70% R.H. which might contain a lot of moisture and have a high dewpoint (i.e. high risk of condensation) and want the fan to run, or I could have a cold bathroom (perhaps a window is open somewhere) and just 12°C and 70% R.H. (much lower risk of condensation) and have no need for the fan to continue to run. But a fan controlled by R.H. cannot tell the difference at all. In fact, my fan makes exactly this mistake and runs for brief periods when cold external air gets into the bathroom through the fan itself at night (because the backdraught shutters are never 100% effective). With all the electronic devices we have these days (I even own a CO alarm that also measures temperature for some reason), why are humidistat extract fans still using solely R.H. to decide whether to switch on or off? Would a basic computer (probably as basic as a pocket calculator) and integral thermometer really cost the earth? (The question is rhetorical). Anyone know an extract fan in which you can set the maximum desired dewpoint temperature of the air instead of the R.H.?
Can’t answer your question but I’ve had great experience with a dmev fan which is permanently on and the humidistat enables boost mode for a set length of time. Underfloor heating being used to keep the minimum bathroom temperature to a certain limit.
The best option is a centralised system with one extraction unit in the loft that can connect several vents. Stand alone fans that are wall mounted create thermal bridges because they are directly connected to outside.
Well done - you didn't even mention the old chestnut aka backdraft shutter. The home owner asks for an extractor fan, so the builder finds the cheapest fan at Screwfix. Obvs a shutter model costs more, so the home owner ends up freezing his/her cods off and/or paying through the nose to keep the room warm. Even more brutal if you have 2 extractors in the same room. How many times have you seen this?
I open a window even in winter, works better than the enviro vent i have. Granted some may not have windows. Close the door, vent out the moist hot air. Open window vents. Fairly simple stuff.
Easy way to measure real time static pressure is by attaching clear pvc tube half filled with water to the duct close to the fan and measure difference in water levels when fan is running, I deal to select pipe size for long runs,
Best would be to replace the fan by a whole house ventilation unit with remote control/humidity sensor and have it ramp up when necessary, and never have it turn off. Also, remember that the air needs to come in from somewhere otherwise you're just making a vacuum!
@@efixx Correct, and it also adds some bends too. Not to mention retrofitting whole house recovery... Easier to build a whole new house almost if it's entirely brick and concrete. That aside, this video intrigued me to replace my fan. It's a cheap design model but the amount of cubic meters per hour compared to the decibels it made it seemed quite on par with premium models. I should definitely look into one for myself. In fact, it also seems that the manufacturer is listing the cubic meter airflow for covered design fans without the cover plate installed while they are obviously meant to be used with the cover. Shady marketing.
I have a cheap fan in the bathroom and it does the job super well, meaty because we have a natural air draw through the tubes and at the opposite side a air inlet feed from the kitchen.
I'll be showing this to my boss. All ours are on the lighting circuits without the 4th wire to run the run on timers, the amount of flex ducting is hideous, and a pain to clean.
I’m considering a DMEV for a living room in an old cob cottage, which has an existing ventilation pipe from an old wood burner installation. The other side of the wall is an A-road. Are there any good quiet, effective DMEVs (room is prone to mood) with HEPA style filters to ensure good air quality both inbound and avoiding recirculating extracted particles from inside?
If you have a longways to go it may be better to get a pull fan mounted on the outside. "Pulling" the air is easier than "pushing" the air. After all your goal is to move air, not to build up pressure. Sure the wiring may get a bit more annoying but it's way better than mold buildup.
Don’t bother with intermittent, go straight for the trickle/boost type. Check out the Vectaire ELX1003 for longer duct runs over 1.5m and the EL1003 for short runs or straight through wall. 8l/s trickle means the room stays fresher…boost to max when showering/ no. 2’s 😂 This meets building regs for domestic. 13l/s trickle for kitchens and utility rooms.
bought a 12 year old house and found that the builder just drilled a small hole in the exterior cavity wall and stuck a fan on one side and a cowl on the other. No ducting between the two walls. Whats worse is that the hole is probably 2 inches in diamiter so what little air can be pushed through that is likely venting into the cavity
Insightful knowledge. The title of the video was the shocking truth about extractor fans. I have found little shocking facts from this video. What aspects are shocking or highly insightful about Extractor fans. Why I have found shocking is that simply opening a window to ventilate us much more effective in managing a humid or condensing environment in a bathroom. My vision is that bathrooms in homes today are simply designed inadequately and a extractor fan is simply a symptom of a design flaw. Would like to hear if there is any truth to this. I have always found duct fans limited in their functional and capacity. I have had a loud extractorfan installed because of building code. The bathroom is built on an I terror facing wall, with no wall being next to or an exterior wall. There is all this refined and quasi placed ducting to manage a ventilation system. The problem I see is that the fan does pull humidity and condensation, bit there seems to be an area of static area across from the ventilator that does not clear quickly. While all other walls are dry quickly, the furthest wall stays condensates for a while even at maximum ventilation rate setting. The radiator fan border the door, which has a open slot at the bottom for ventilation. What I see happening is that there seems to be a strong air flow from this slot to the extractor fan. I can clearly feel as air flow from this slot to the fan box. The rest of the bathroom seems stale in airflow. This has given me an impression that likely an extractor fans performance is perhaps also only as good as the way a bathroom is built and in which spot the ventilator is actually placed in the space. If I could choose I wouldn't want my house dependent on an electrical system but rather gave natural ventilation. Is think this would leave us less dependent on energy consumptive technologies and maintenance and perhaps unnecessary overhead cost. Electric does have its conveniences. But in a world where the is increasingly designed to cater for elictric systems, which come with priveleges, but also obligations (which are often glanced over), makes me more excited in the current climate to thonk of ways to passively ventilate a bathroom rather than being dependent on more costly active systems. I am curious to know if others share this view in this energy transition zeitgeist and what similar or more refined ideas people may have.
I’d suggest you checkout our CPD on ventilation and the building regulations. As buildings become more airtight and insulated the requirements for properly designed ventilation increase.
Envirovent is premium? I have one of those pieces of trash keeping me up every night.. the bearings are made of beach stones.. at least that's my best guess based on the sound
20yr old Care Home. No maintenance done since indtallation. All bathroom ventilation systems were clogged with dust. Got a contractor in the clean with rotating brushes and vacuum. Amazing difference. Cleaning these systems is rarely considered. I have a heat recovery fan in my bathroom with a straight exit throught the wall. It needs yearly cleaning. Not easy Fortunately I have an air compressor for. Job done. But think of sll those thousands of installations with years snd years of dust build up.......oh dear😢
I had a customer that got me to wire his 1M wide 150mm extractor hood , It pushed out so much air his gas backboiler fumes were being drawn into the house.
Great video ;) I'd like to ask why extract fans have a delayed opening cover - why delayed? But technically you're removing water vapour, not steam. Steam is dry.
If not putting a carpet on the floor and putting a drain instead there, the majority of the water goes away. Warm floor and walls are good if want no condensation, but then humidity has no where to go, but, or letting walls be cold, the condensation grabs there and the water streams down...to drain. If I had to, (never had, actually never seen screamers on bathrooms here in Finland) use the fan, I'd surely put it on the attic alongside the kichen one. And a real one, slow spinning, not these toys you like there...
we live in a tower block with a passive vent connected to a central duct...the vent has always been noisy, so we cover it regularly....how can i find a vent cover that will be quieter?
I dunno what the regs would say about it...But if I was in your situation I'd remove the vent cover, clean the duct behind, and then line the first 9-15" with some suitable foam. This would at least dampen the sound coming from the ventilation system. Do check on this though, as foam tends to be flammable and would *not* be suitable if that ventilation forms part of the buildings fire/smoke management system. 🚬⚖⚠
I had my new bathroom fitted, the ducting in the loft goes up to a vent tile in the roof. The flexible ducting in the the loft is quite long and has a hanging bend, this bend is full of water, should I remove and empty it? After that should I shorten it and make it straight? Sometimes I get water dripping from the fan (condensation).
Do you know whether or not the Envirovent SIL100 Silent-100 Axial Silent Extractor Fan Timer Model (White) has fully stainless steel bearings? There is no info on their website
Good informative video. The fan in my bathroom is on the wall & leads straight outside. It is 20 years old, noisy and only works with the light on. Is there a better option and are they easy to install?
Humidistat fans are your best option, but if you don't know what you're doing, you should get a qualified electrician to change it. Should be simple in theory, but if any problems come up then the experience will be invaluable.
Do any of them really work that well,look outside on a cold day,you never see steam coming out the extractor when they are on,if you can just open a window up,you do then...
@ That's because the water vapour has had time to cool down to ambient temperatures through the fan and ducting. You will see vapour in cold conditions when the fan is wall mounted and directly extracting.
I am looking into replacing our bathroom extraction fans. Besides what's immediately visible list those Envirovent systems, would I still also need something like a Manrose MF100T in-Line Extractor Fan up in my loft? I would like a single inline extractor fan to support two bathrooms (family + on-suite) - since they are close to each other.
Tbh I think 4 inch (or "100mm") fans are pathetic, I'd much rather have a 12 inch (or "300mm") and with adjustable speed. Admittedly what I came across was in a kitchen not a bathroom, but about 17 to 20 years ago, a family I know lived in the most random old-fitted-out "multi-storey house above a shop" ever (sadly since converted to boring flats) with a weird random layout and multiple bathrooms (one leading into one of the bedrooms and another leading into the laundry room), and the kitchen had a 12 inch (or "300mm") Vent Axia T-series wall extractor fan, yes in a domestic house! I can't see why one couldn't be used in a bathroom either?
Had to replace my old extraction fan as it stopped working after a couple years after a bathroom refit took the manufacturer details and found it was about £7 on ebay went to b&q a got a marly fan about £40 has been going years
1 bends equals 16m of straight equivalent? Is that just for flexi duct? I thought it added 1m per bend. Would this be the same if i install MVHR with a 90mm semi rigid duct for each bend?
Unfortunately you've not addressed the inline fan option which is typically quieter and more powerful such as the Manrose. Additionally this has 3 power level choices.
Fans in bathrooms need controlling with a humidistat!. When controlling humidity/ black mold formation dry air is the answer. We use to fit positive pressure axial fan units in loft ceiling or hallway dragging fresh dry air from outside the property that pressurised the dwelling with fresh dry air, pushing contaminated air away outside. The fan setup and running would acheive the set amount of air changes! Job done apart from regular maintenance. NU-air units.
When I was a child I used to collect anything I could get my hands on to do with tractors. I loved them. I even had a ride on one. As I've got older my interest in tractors has fallen considerably to almost zero. I'm an ex tractor fan.
Like fighting a uphill battle. Apparently when I have the NICEIEC do our assessment for ventilation we are the only company in a huge radius. We sign off all new installs with a certificate and notification to building control. Bloody no one does it, no one does it right it’s a joke. Maybe add the ventilation course on to the apprenticeship course just to give some basic knowledge on the subject
Cause we are fed up being scammed and paying to work for marketing companies like the nic.... im either qualified or im not, paying to be * member* is a scam, really is. Just do what everyone else is doing, notify nothing.
@ agree with the “scheme cough cough scam” but it’s doing a course be it at a college or even at a manufacturing company it gives a better understanding of what should be done. Also using a dedicated tester to commission the fan will give you an idea if you have installed the correct unit for the space. I have seen so so many piss poor installs for Ventilation it’s a joke. Provides me with lots of work which is good but not good for the customer. Should not be having to pay twice for dumb installers. Like I said if basic installation methods and basic regs were taught in the electrical apprenticeship course it would help with what the video is banging on about .
Half the problems I had were that builders would insist on underspecced fans and then complain when I failed their fan tests. Company told me to fudge the numbers to make them pass. I wouldn't put my name on those certs and eventually left.
My experience of UK builders/contractor's is many lack basic knowledge of ventilation principles. Here is another common mistake, fitting a bathroom extractor with a door that shuts tight. Where is the air drawing from?? Most extractor's I see are absolutely useless.
If the extractor is pumping air _out_ and the soil pipe is open vented (As all should be) chances are the main _source_ of air would be through the open end of the soil pipe, through the U-bend and out of the toilet... 🌬🚽🤮 And if the soil ventilation *isn't* all that great in a system with many toilets connected (Thinking of my mate and the vertical drain which serves his and 15 other flats) you're going to be breathing in more Hydrogen Sulphide than air... ☠
@@hughmarcus1 An extractor fan does the same, the air you blow out as to be replaced, or you would create a vacuum. That air as to get in from outside.
@sparking2016 Once fitted a humidistat fan and it would turn off and then not restart. Turned out the heat from the dropper resistor would desiccate the sensor 🤦♂️.
Most new builds use Envirovent but don’t use the correct ducting so become useless. They also used a 10m run with kinks, so naturally water ran back down. I’ve had to switch to an in-line extract instead.
The video title made me think that this is some sloppy put to gether video by some guy from india, I was pleasantly surprised that this is an informative video. Maybe you should rethink making your titles more descriptive?
Sucks the heat right out the bathroom that 100mm HOLE does warmest room in the house not no more since I fitted a fan,open the window used to work fine never ever had any mold house is 100years old.Heat Pump doesn’t supply enough heat for towel rails we are going backwards £60 spent on heating the house now and it is never above 19c.
With ducting a centrifugal fan is really needed for decent performance against back pressure. I have a loft mounted 150mm centrifugal fan reduced down to a 125mm inlet grill for bathroom. I don't see the point of these little 100mm wall mounted fans that do very little.
Dont buy envirovent on the basis of thr 5 year warranty. I did and when i had an issuez they declined the claim. Even though i bought brwnd new from Amazon. They claimed that wasn't an authorised reseller. Will never buy that brand again. Hope this helps any other future customers.
It was only a matter of time before you had an onlyfans episode.
😉
@@1210mk5g 😄
🤣🤣🤣
He'll regret it in years to come
Brilliant.🎉🎉😂
I bought a 12 year old house and there was a small amount of mould in the bathroom. The large housebuilder had fitted a mains ceiling fan on the opposite side of the wall to the bath. It made a noise but would not hold a single sheet of toilet paper up with its suction, I kid you not. Looked in the loft and "ducting" to a roof vent was made of various leftover bits including a flexible toilet connector taped together! Got a Manrose MF100T, put the vent right above the shower and it's been great. Now a flattened toilet roll tube can be held up by the fan, and that's on medium setting!
Guys... you guys have my subscription. You guys are the only ones i have found on youtube that actually get it, and understand the importance of a video WITH A TEST COURSE. The real people out here are interested in retaining the information, not just passively watching youtube videos and forgetting about it a week later.
Very few people want to pay for adequate ventilation in my experience. I've known people who had fairly large and expensive 'luxury' bathrooms installed, but want to use the cheapest fan possible - using the existing ducting or core hole to save a few quid. If there's a loft space above, its fairly easy to install a 4 or 5 inch inline fan and extract via a soffit in many cases. If the fan is mounted above the insulation, they can be extremely quiet - all you hear is the sound of air air being pulled through the inlet grille.
If you use a 5" grille, 5" ducting and have the fan set to the lower speed, it can be almost silent, but still retains a very good extraction rate.
Having to core a hole through a wall, get up a ladder outside to mount a grille, run sensible dusting etc can take up the best part of a day in some cases. Including the cost of an adequate fan, insulated ducting, install an accessible isolator etc. may well cost £400, but is generally money well spent IMO.
When a customer says they want to use the existing fan in their nice newly fitted bathroom - just because it seems to work and saves some money I despair!
If a fan wont even hold a single sheet of toilet paper to the ceiling/wall inlet, then you know its not going to perform very well!
Humidistat fans can cause grief in certain properties. We retrofitted one in a basement in Kensington and would run constantly no matter what humidity sensitivity it was set to - purely as the basement had high humidity all year round due to damp issues.
Good job we are all fans of the channel. I'll get me coat.
Blown away by the support 🤣
Only fans is an entirely different thing as well
I used to like farm vehicles - but now I'm an ex-tractor fan.
I gave up on standard extractors and instead fitted two in-line fans in the loft. They simply amazing, and have (especially in the bathroom) completely eliminated shower condensation.
@@barryfoster453 WTF. You don't ever, ever ventilate directly to the loft space!
@@markrainford1219 Wouldn't want the woodlice to die from dehydration.
@@barryfoster453 You crack on then, mr 'engineer'.
@@barryfoster453 What are you a qualified "engineer" in? Civil, electrical, mechanical? I'm a spark, I ain't going to touch gas or pouring concrete. Your 49 years of experience means nothing at all if it isn't in the right field. It's really difficult to check if you have sufficient ventilation in a roof space, because you can't test the static pressure accurately. Sure, it 'might' work. I actually care about the quality of my work so I want to be sure.
In-line fan is the best with insulated ducring and isolator switch. Venting outside of course.
What lot of people fail to understand is that you can put hundred extractor in your romm, if there is no way for the air to enter from an other way, there will be no extraction because the room will be in depression and the air flow will stop.
There will be some not a lot I clearly said no most bath rooms have a door with gaps in hundreds of fans in a small bathroom will create passive pressure drawing airbon though the door is gaps and any key hole, not a lot but enough to clearly make your statement of no air flow wrong even one drop of snow at a single walearher station. Is enough for a betting company to be legally obliged to pay up a white Christmas bet,
What's not been mentioned here (directly) is that most of the types of fan shown (I can't for the EnviroVent models) are not suitable for use in fully ducted systems. If you have the space, i.e., can fit the fan in the loft, a high pressure duct fan is a far better option.
Also, if using ducting, it's best to use insulated ducting to reduce condensate formation in the ductwork.
@@mikepeter1323 also when there is no makeup air you start pulling in air from places you don’t want to like around lighting, closed windows, electrical outlets and this in turn will bring with it the dust from insulation and other contaminants that you don’t want. You could also be pulling in un-conditioned air and expelling the conditioned air that you paid to cool or heat which is a kick in the wallet lol. Same happens with unbalanced hvac systems!.
Your doors are not airtight.... at least I hope they're not 😂
@@BadandMadMartin wherever it comes from, you can’t just extract unless it’s going in from somewhere
I think it is important to note that the different performance of fans is not just due to quality differences. The type of fan design usually matters the most. There are different fundamental designs optimized for high flow, high pressure, or a bit of both - but you inherrently can't be great at both. The design of fanblades is a very well explored science, so don't let marketing persuade you that some expensive fancy fan has the best of both worlds. This is a design tradeoff you have to maks - so use the appropriate type for the spesific situation.
High flow fans typically have fewer, larger and more spaced blades with deep angling to scoop up a lot of air, but they work best if you are venting sirectly to the outside with no or minimal ducting. They drop in performance very quickly if there are restrictions and might even stall out completely if used inappropriately.
High pressure fans have many, dense, shallow-angle blades to maximize pressure (ie. how well it can force air to move against restrictions, like long ducting or filters). While every fan will lose performance with long and winding ducting, these will suffer least.
Personally I would go for a model with an adjustable hygrostat (humidity meter/controller). These sensors are cheap and shouldnt add much cost, but it can can save both noise and energy by running on minimum or even turning off when the room is already dry. Remember that in the winter you are venting out the heat in the house, so you don't want excessive venting when its not needed.
Having a "boost" button that temporarily runs the fan full speed can be nice if you want to get rid of toilet stinks quickly. Thats also a common feature.
In my opinion, it's actually best to go for a Heat Recovery Fan which is on all the time. Many have a boost feature which you can activate while you're in the bathroom.
Bingo, this is what I did. Combined with a HEPA filter on the inlet. Wish I had the space to plum a full system in this old House
Fitting a mvhr system in a rewire just now and although it's a bit annoying it will be an amazing system when up amd running
@@christophergallagher3845
What, a full house one, or a room one?
@@barryfoster453 full house it's a unit made by vent axia sits in attic has inlet and outlet to the roof and every room has a vent to it via a manifold for both extraction and fresh air from outside
@@barryfoster453 it's a vent axia system it uses a rigid ducting its only feasible in renovations or new builds it would be hard to retrofit to a house without destroying every room
I ended up simply installing a PIR unit onto my envirovent 100 and it drastically improved the extraction process overall, stink humidity etc with a run on timer, along with ensuring a 10mm gap under the door.
When I fit inline fans and ducting, I put the fan as close to the outside vent as I can. Less pressure to push against and let the power of atmospheric pressure fill the slight vacuum behind.
Great tip
If only architects paid attention to that idea and roofers didn't occasionally forget the vents and install them near the apex :)
I always had this in my mind but never looked into it. It's a great idea, although not always works out .
The position of the fan is irrelevant. The Total Static Pressure is the sum of the pressure resistance in the duct on either side of the fan. Only use an axial fan as tested here if there is a very short duct run. If the air is to be ducted use a wall mounted centrifugal extract fan or an inline fan. Axial fans make noise and do little else.
@@TomB-o4v That's a bit harsh. Plenty of axial fans are capable. Sure, you want to get the anemometer out to check the extraction. For most domestic settings a centrifugal fan is not necessary (or available). Inline fans are also axial, and can present maintenance issues.
I added 3 flow switches when I rebuilt our bathroom. 1 on the cold feed of the shower, bath and toilet which triggers the fan, 1 to the hot feed to the shower & bath (also triggers the fan, added as redundancy).
These are connected to the fan where a lighting circuit would normally be connected to trigger the fan, so it's using the built-in timer that keeps the fan on after the water stops flowing.
Lastly, there's one on the hot feed of the shower (triggers the lights in the shower cubicle. This has a custom built electronic timer that keeps the lights on for 6 minutes after the water flow stops).
There's a sink in the bathroom, but I intentionally put the flow switches after the sink in the water circuit as there's no need for the fan to come on when just brushing teeth or washing hands.
With this setup, the fan only comes on when the shower or bath is running, or if the toilet is flushed. It then stays on for 10 minutes or so after the water flow stops.
If we ever need to force the fan to come on, we just turn the bath or shower tap on for a second.
If we ever need to force the fan off, we just use the fan switch outside the bathroom.
We also have a movement sensor that's controlling the lighting, with a 5 minute delay before it turns off.
Simple setup that works a treat and has been reliable for over 10 years.
Great idea and not something I thought of. I simply installed a PIR unit onto the fan with run on timer, as the room gets plenty of light. Granted it comes on when brushing teeth, but ventilation is good no matter what. Chopping 10mm from the bottom of the door also helped greatly.
Yes. I much prefer the idea of an external over-run than the cheap and nasty electronics built into many fans, yet couldn't manage to find a device that closes the contacts for a set period commencing when the switch (flow switch in your case) opens contacts rather than commencing when the contacts close.
Since then, I've discovered that Italian domestic wiring LOVES using relays. They often use relays instead of 2 or 3 way light switching, and on stairwells they often use timed relays. Practically ever home has a relay or 3 in its lighting circuits. Looking at the datasheets for "Finder" (other brands are available) _temporizzatore luce scale,_ I learned that these can be set to run exactly as I would have needed for an over-run relay.
So this would be an alternative to custom building an electronic timer (though I'd love to see the circuit diagram if you are willing to share it).
Nice presentation, however I mis the notice of the supply of air in a (bath)room. If you want to suck out moist air, you need to to supply fresh air. Next if you live in a area with lots of bugs like 🦟, take a vent with a filter or beter with flow-shutters etc.
Well done 👏🏼 and thanks for the info and demo 👍🏼🏴🇬🇧
These in wall fan bug the ever loving hell out of me also the ability for people to turn them off cause of the noise my mother was terrible for not turning it on before a shower. Just use a decent in-line fan with hard tubing! dont bother manufacturing them crappy ones, and the cost will go down! If the uk routinely adopted the European standard of heat recovery ventilation, then there would be even less of a problem, we are SOOOO far behind it's not even funny. Conduit wireing for easy rewire or additions is another perfect example of how far behind we are. I could go on all night, but i got a whole playlist to catch up on. 👍
Putting moist contaminated air through a system with filters is pointless
If housebuilders cared enough to pay the extra price for MVHR systems I will eat several of my hats. In my experience they will only do it if the council wants them to meet noise/pollution regs. Being near an airport or motorway, etc. The few times I was asked to use solid duct in a roof was when the site manager knew that plot was getting inspected for an award.
Heat recovery ventilation is still pretty rare here in mainland Europe. They are starting to put them in new homes now, partly because of the new and more onerous EU energy label scheme.
Heat recovery ventilation is the “standard” in Europe? Dream on. It’s very rare there. I’m not aware of it being the standard anywhere in the world, even if it’s the ideal in most places.
One additional thing to consider is how well the fan seals the ventilation hole when not in use. Cheap fans often don’t have any closing flaps and even those on the premium fan looked to be quite thin plastic so offer little insulation.
Building regs required an extractor to be fitted in our utility room despite there being an external door and no buildup of moisture occurring. In winter it was basically a 4” hole straight through to outside so I ended up having to stuff the fan hole with rockwool to stop the wind blowing in, thus of course defeating the purpose of having a fan fitted that we never used anyway.
We had the silent serie for Some years,3-4.. and we reduced& stopped mould grow in the bathroom.
but we still had mould grow in the bedroom.
So i changed the silent serie for a vent axia multihome, that Provides us from fresh air 24/7! No more mould in the bedroom since we ventilate 24/7.. 🤞🏻
I tried 3 different fans in my bathroom, cheap or expensive the ones that got the job done were noisy as hell and silent ones weren't pumping for sht. Then I ordered a noname one with a 4-speed inverter motor from taobao. THAT Is what actually solved my problem. Speed 1 is almost inaudible even inside, speed 2 is inaudible from the bordering bedroom even in total silence, speed 3 does a fantastic job of clearing heavy fog and speed 4 can clear out a chemical weapon faster than you can breathe it in.
I’m thinking of installing MANROSE LP150STW 150MM (6") AXIAL KITCHEN EXTRACTOR FAN in my bathroom. It suffers from mould and currently doesn’t have any extractor fan. Very useful video
Great video but you've missed the one item that will trip up any casual fan fitment. They are a controlled fitting under B.Regs ie. Building Control must be notified and latest regs says the installation MUST be tested AS INSTALLED, to show it meets the performance required, by a CERTIFIED professional, and results forwarded to Building Control.
Good point - we discussed this issue during a recent live stream - th-cam.com/users/liveOlTniinvHCw?si=uRrbrX3c7lVvMfeR
So, just somthing else I wont be notifying, excellent.
Really! What else are building control going to stick their oar in to next. I’m sure we are all going to die if we don’t have a fan in our bathrooms and it’s thoroughly checked by a well paid fan professional.
I’m not renting my property, it’s mine. I own it. If building control did what they should then I wouldn’t be spending huge amounts of money to fix the bodge done by the cowboys that built it. Sadly this is still going on with new builds so it’s not like building control are actually doing anything for the money they cost.
Provided it’s safe then it’s nothing to do with building control and they can jog on.
@@davideyres955
I feel like that. We had a wood burning stove, but didn't tell anyone (and it didn't go into a liner, either), and in my bathrooms, I have normal light switches, not pullcords. My house, my rules.
They are nice fans, but not many customers will be happy paying £200+ for a bathroom fan...
Shop around - www.electricalsonline.co.uk/products/envirovent-sil100t-100mm-ultra-quiet-wc-bathroom-extractor-fan?gad_source=1&gbraid=0AAAAABYQt6LNl7PMIEpZ13qoWgxEYbz46&
LOL! I bought a large radial duct fan that delivers about 80 liters/second at 100 Pa (or 40-45 l at 200 Pa), for like half that.
I use it in a sort of reverse configuration when I need som extra ventilation in my apartment - "pushing" in fresh air in from the outside (creating overpressure), then open the vents (going to the air ducts in the house) all the way. That increases the airflow (suction) thru the vents a lot (due to larger the larger static pressure difference). Perfect for cooking - get rid of the fumes quickly without having to deal with grease building up in the fan.
I put 150's in the shower/bath room... A metal insulated duct sorted out the performance issues we were having. Fan runs-on for 15 minutes based on the humidity. And here I was switching the fan off after I had finished showering.....
Placement of extractor fan and and available airflow/ventilation into the bathroom/kitchen is also crucial to maximise fan extraction. A suitable gap must be under the door, or an internal wall or door vent/grille, is needed. An under door gap and door vent would be optimal.
If the fan is placed between a window and shower/bath and you open the window, the fan is going to extract the air from the window first, leaving the condensation to travel across before it's extracted. The same applies with door gap/grille/internal wall vent airflow and fan placement. Basically install the fan in the optimal placement for airflow extraction, that prevents condensation from leaving the zone 1 area.
If i could, i would draw a diagram to explain and make it easier to understand.
Optimal fan placement, zone 1 if door gap/door grille/wall vent is opposite to shower/bath tub, i.e airflow/ventilation on the left of the room and shower/bath on the right of the room, or visa versa.
Airflow/ventilation in a bathroom, is crucial to condensation extraction. Without airflow/ventilation, an extractor fan can not do the job it was made for, as it can not extract condensation from an unventilated room. A window trickle vent being open in an airtight bathroom, is not enough, even less so with a bathroom that has external walls. And you'll notice this in colder weather, when condensation is dripping on those external walls.
If you have the right extractor fan for the size of your bathroom and you have condensation dripping on the walls, then the extractor fan placement is wrong, or there isn't adequate ventilation, or possibly both. Extractor fans need to be cleaned and ducts checked every 4 months or so.
Or if you're in the UK and your bathroom is a cold room, double insulate above in the attic. Use expanding foam to seal any air gaps in the attic above the bathroom i.e. wall plates etc, also make a box from insulation board (Kingspan) and place it over the extractor fan unit in the attic and seal with expanding foam. Double check you have a backdraft for the extraction fan.
Another reason for cold external walls, is that people do not seal the tiles to prevent moisture from reaching the plasterboard, as these areas are generally not waterproofed prior to tiling. Tiles are porous, so is grout and over time moisture will make its way to the plasterboard if you have a lot of condensation. So when the temperature drops outside, even the smallest amount of moisture in the plasterboards or in the tiles, will turn those walls into ice buckets.
What an informative and professional video.
I've been fitting the cheap 150mm extractor fans in our bathrooms for a few years now (from Screwfix). I don't think the 100mm/4 inch ones standardly specified in UK bathrooms are up to the job on a straight run out of the wall, never mind when coupled with flexi duct. I always run them straight out of the wall using a solid duct too. I don't like the idea of putting them through the ceiling and into the loft, what do you do then when you want a loft extension? Also, since the air has to come in from somewhere, trickle vents open are a must, or something else - not that our homes are air tight enough for it to be an issue generally, there's normally some nice gaps under the bath tub or where pipes come out etc. but it is a consideration.
Cheers Gents, we have a 100mm in a bathroom in a listed building. I now know what I am looking for when it comes to best for the hole in the wall
I went for a quiet fan which I don’t mind running 24/7 if it has to, and connected it to a smart relay so my smart home runs it as long as the humidity is above my set target 👌
Extraction is tricky. I went to the trouble of installing an inline fan for my kitchen and use that instead of the ceiling mounted centrifugal, and replaced half of the flexi hose with rigid; result is much quieter. However, a second inline did not perform much better when installed to extract bathroom (with flexi duct), and generated more noise than the existing centrifugal. Due to constraints of installation (inlines can't be mounted at odd angles), it had to be mounted to the wooden beams above, and a 10mm rubber damping mat was not enough to isolate the noise. It's a perception thing but the greater low frequency energy from above made it feel louder. After watching this I think the bathroom shrouded inlet design is also impeding air flow to make it quieter, so I will remove it.
When fitting a fan with a humidity sensor, never set the sensor to anything below 50% as very often the air will be naturally above this level, a low setting will result in the fan running constantly, generally 75% will be ok.
Remember to add 10mm under cut to door for makeup air
I still don’t understand how Britain lives without proper extractor fans. Damp houses with no ventilation would benefit from a good sized vent!
@@srpacific houses in the UK are generally very cold and inneficient. Power is very expensive (especially in the last few years). Many want to sacrifice poor ventilation for warmth.
We open the windows!
I'm one of very few council tenants who don't have so much trouble with damp, and my habit of leaving the windows latched into the „vent“ position is most likely for why. I only close them fully (And still leave the frame vents open) during extreme weather events. 👍
I also engage in the German practice of _Stößluft_ - The act of throwing open all the windows to completely replace all the air in the house (Usually, during mid afternoon when the air is still warm-er) - To freshen the atmosphere before turning on the heating in the evening. It drops the temp by a few degrees (Moot in my case as I can't afford to use the heating anyway) but it really does help get rid of the stale air and may contribute positively to health. 🌬🇩🇪👍
@@srpacific first time i saw these was in britain 20 years ago.
Humidistat fans are good (I have one myself) but the ones I have seen share a basic flaw: they all sense relative (R.H.) and not absolute humidity.
If I want to avoid condensation, I need an absolute humidity level (defined in terms of g water/kg dry air) that avoids condensation forming above, say, 14°C. The absolute humidity is in a fixed relationship with the dewpoint (the temperature at which the air reaches 100% R.H.). Absolute humidity can be known using a wet-bulb thermometer as well as a normal thermometer, or, if you have a way of measuring R.H., you can very easily know it from the 'normal' dry-bulb thermometer temperature and the R.H.
Relative humidity isn't a very useful thing to monitor in order to control a fan. I could have a bathroom with air at 23°C and 70% R.H. which might contain a lot of moisture and have a high dewpoint (i.e. high risk of condensation) and want the fan to run, or I could have a cold bathroom (perhaps a window is open somewhere) and just 12°C and 70% R.H. (much lower risk of condensation) and have no need for the fan to continue to run. But a fan controlled by R.H. cannot tell the difference at all. In fact, my fan makes exactly this mistake and runs for brief periods when cold external air gets into the bathroom through the fan itself at night (because the backdraught shutters are never 100% effective).
With all the electronic devices we have these days (I even own a CO alarm that also measures temperature for some reason), why are humidistat extract fans still using solely R.H. to decide whether to switch on or off? Would a basic computer (probably as basic as a pocket calculator) and integral thermometer really cost the earth? (The question is rhetorical).
Anyone know an extract fan in which you can set the maximum desired dewpoint temperature of the air instead of the R.H.?
Can’t answer your question but I’ve had great experience with a dmev fan which is permanently on and the humidistat enables boost mode for a set length of time. Underfloor heating being used to keep the minimum bathroom temperature to a certain limit.
The best option is a centralised system with one extraction unit in the loft that can connect several vents.
Stand alone fans that are wall mounted create thermal bridges because they are directly connected to outside.
I'm a huge fan of this video.
Well done - you didn't even mention the old chestnut aka backdraft shutter. The home owner asks for an extractor fan, so the builder finds the cheapest fan at Screwfix. Obvs a shutter model costs more, so the home owner ends up freezing his/her cods off and/or paying through the nose to keep the room warm. Even more brutal if you have 2 extractors in the same room. How many times have you seen this?
I open a window even in winter, works better than the enviro vent i have. Granted some may not have windows. Close the door, vent out the moist hot air. Open window vents. Fairly simple stuff.
An interesting video.
Thank you
19:00 cylindrical drill through cabinet from below to access
Easy way to measure real time static pressure is by attaching clear pvc tube half filled with water to the duct close to the fan and measure difference in water levels when fan is running, I deal to select pipe size for long runs,
Best would be to replace the fan by a whole house ventilation unit with remote control/humidity sensor and have it ramp up when necessary, and never have it turn off. Also, remember that the air needs to come in from somewhere otherwise you're just making a vacuum!
Whole house ventilation is a great solution but can be a challenge for retrofitting.
@@efixx Correct, and it also adds some bends too. Not to mention retrofitting whole house recovery... Easier to build a whole new house almost if it's entirely brick and concrete.
That aside, this video intrigued me to replace my fan. It's a cheap design model but the amount of cubic meters per hour compared to the decibels it made it seemed quite on par with premium models. I should definitely look into one for myself. In fact, it also seems that the manufacturer is listing the cubic meter airflow for covered design fans without the cover plate installed while they are obviously meant to be used with the cover. Shady marketing.
I have a cheap fan in the bathroom and it does the job super well, meaty because we have a natural air draw through the tubes and at the opposite side a air inlet feed from the kitchen.
Thanks for the video =)
1:05 they might look similar on first glance but there's 15% difference between the cheap and the expensive model. That can be significant.
I'll be showing this to my boss. All ours are on the lighting circuits without the 4th wire to run the run on timers, the amount of flex ducting is hideous, and a pain to clean.
I’m considering a DMEV for a living room in an old cob cottage, which has an existing ventilation pipe from an old wood burner installation. The other side of the wall is an A-road. Are there any good quiet, effective DMEVs (room is prone to mood) with HEPA style filters to ensure good air quality both inbound and avoiding recirculating extracted particles from inside?
If you have a longways to go it may be better to get a pull fan mounted on the outside.
"Pulling" the air is easier than "pushing" the air. After all your goal is to move air, not to build up pressure.
Sure the wiring may get a bit more annoying but it's way better than mold buildup.
Well thats cleared the air !
Don’t bother with intermittent, go straight for the trickle/boost type. Check out the Vectaire ELX1003 for longer duct runs over 1.5m and the EL1003 for short runs or straight through wall. 8l/s trickle means the room stays fresher…boost to max when showering/ no. 2’s 😂 This meets building regs for domestic. 13l/s trickle for kitchens and utility rooms.
I don't know why VMC systems aren't more widely used in the UK. Much more straightforward and better performing to ventilate the entire house
This system is mandatory in France for new builds since the 80's
bought a 12 year old house and found that the builder just drilled a small hole in the exterior cavity wall and stuck a fan on one side and a cowl on the other. No ducting between the two walls. Whats worse is that the hole is probably 2 inches in diamiter so what little air can be pushed through that is likely venting into the cavity
Insightful knowledge. The title of the video was the shocking truth about extractor fans. I have found little shocking facts from this video. What aspects are shocking or highly insightful about Extractor fans. Why I have found shocking is that simply opening a window to ventilate us much more effective in managing a humid or condensing environment in a bathroom. My vision is that bathrooms in homes today are simply designed inadequately and a extractor fan is simply a symptom of a design flaw. Would like to hear if there is any truth to this. I have always found duct fans limited in their functional and capacity. I have had a loud extractorfan installed because of building code. The bathroom is built on an I terror facing wall, with no wall being next to or an exterior wall. There is all this refined and quasi placed ducting to manage a ventilation system. The problem I see is that the fan does pull humidity and condensation, bit there seems to be an area of static area across from the ventilator that does not clear quickly. While all other walls are dry quickly, the furthest wall stays condensates for a while even at maximum ventilation rate setting. The radiator fan border the door, which has a open slot at the bottom for ventilation. What I see happening is that there seems to be a strong air flow from this slot to the extractor fan. I can clearly feel as air flow from this slot to the fan box. The rest of the bathroom seems stale in airflow. This has given me an impression that likely an extractor fans performance is perhaps also only as good as the way a bathroom is built and in which spot the ventilator is actually placed in the space. If I could choose I wouldn't want my house dependent on an electrical system but rather gave natural ventilation. Is think this would leave us less dependent on energy consumptive technologies and maintenance and perhaps unnecessary overhead cost. Electric does have its conveniences. But in a world where the is increasingly designed to cater for elictric systems, which come with priveleges, but also obligations (which are often glanced over), makes me more excited in the current climate to thonk of ways to passively ventilate a bathroom rather than being dependent on more costly active systems. I am curious to know if others share this view in this energy transition zeitgeist and what similar or more refined ideas people may have.
I’d suggest you checkout our CPD on ventilation and the building regulations. As buildings become more airtight and insulated the requirements for properly designed ventilation increase.
@MED Cool story bra
Do I still need an extractor fan if I live in postcode HG2 0FL ?
No as there is a huge fan base nearby
@@efixx is that like a Homebase for OnlyFans?
Those Envirovent fans look suspiciously identical to the Vent-Axia fans we are more used to in the South.
Envirovent is premium? I have one of those pieces of trash keeping me up every night.. the bearings are made of beach stones.. at least that's my best guess based on the sound
I have a Vent-Axia 'silent' fan. It uses the timber-frame as a soundboard. On a masonry wall it might be silent...
20yr old Care Home. No maintenance done since indtallation. All bathroom ventilation systems were clogged with dust.
Got a contractor in the clean with rotating brushes and vacuum.
Amazing difference.
Cleaning these systems is rarely considered.
I have a heat recovery fan in my bathroom with a straight exit throught the wall.
It needs yearly cleaning.
Not easy
Fortunately I have an air compressor for. Job done.
But think of sll those thousands of installations with years snd years of dust build up.......oh dear😢
I had a customer that got me to wire his 1M wide 150mm extractor hood , It pushed out so much air his gas backboiler fumes were being drawn into the house.
Great video ;) I'd like to ask why extract fans have a delayed opening cover - why delayed?
But technically you're removing water vapour, not steam. Steam is dry.
Thanks
If not putting a carpet on the floor and putting a drain instead there, the majority of the water goes away. Warm floor and walls are good if want no condensation, but then humidity has no where to go, but, or letting walls be cold, the condensation grabs there and the water streams down...to drain. If I had to, (never had, actually never seen screamers on bathrooms here in Finland) use the fan, I'd surely put it on the attic alongside the kichen one. And a real one, slow spinning, not these toys you like there...
Most bathrooms in the UK don't have drains in the floor or even tiled floors, unlike the bathrooms I've used in Suomi.
@dieseldragon6756 The reason I said that was the fact that they do not have drains in England, but fans they have.
we live in a tower block with a passive vent connected to a central duct...the vent has always been noisy, so we cover it regularly....how can i find a vent cover that will be quieter?
I dunno what the regs would say about it...But if I was in your situation I'd remove the vent cover, clean the duct behind, and then line the first 9-15" with some suitable foam. This would at least dampen the sound coming from the ventilation system. Do check on this though, as foam tends to be flammable and would *not* be suitable if that ventilation forms part of the buildings fire/smoke management system. 🚬⚖⚠
Ridiculously expensive now but you can’t beat envirovent…
Use a vent axia revive 7…. Work a treat. Very good for social housing.. use 12v version in the bathroom..
I had my new bathroom fitted, the ducting in the loft goes up to a vent tile in the roof.
The flexible ducting in the the loft is quite long and has a hanging bend, this bend is full of water, should I remove and empty it? After that should I shorten it and make it straight?
Sometimes I get water dripping from the fan (condensation).
Lots of problems - duct should be insulated you should also install condensation trap.
Loratap do a wireless smart switch with 30 minute run off timer for extractor fans. Ideal for inline fans in the ceiling.
Can i add an inline fan to my existing fan or is it just better to lose the wall mounted one altogether
Very informative
Glad you think so!
Do you know whether or not the Envirovent SIL100 Silent-100 Axial Silent Extractor Fan Timer Model (White) has fully stainless steel bearings? There is no info on their website
Trying to decide on one just now.
Good informative video. The fan in my bathroom is on the wall & leads straight outside. It is 20 years old, noisy and only works with the light on. Is there a better option and are they easy to install?
Humidistat fans are your best option, but if you don't know what you're doing, you should get a qualified electrician to change it. Should be simple in theory, but if any problems come up then the experience will be invaluable.
Do any of them really work that well,look outside on a cold day,you never see steam coming out the extractor when they are on,if you can just open a window up,you do then...
@ That's because the water vapour has had time to cool down to ambient temperatures through the fan and ducting. You will see vapour in cold conditions when the fan is wall mounted and directly extracting.
I am looking into replacing our bathroom extraction fans. Besides what's immediately visible list those Envirovent systems, would I still also need something like a Manrose MF100T in-Line Extractor Fan up in my loft? I would like a single inline extractor fan to support two bathrooms (family + on-suite) - since they are close to each other.
Tbh I think 4 inch (or "100mm") fans are pathetic, I'd much rather have a 12 inch (or "300mm") and with adjustable speed.
Admittedly what I came across was in a kitchen not a bathroom, but about 17 to 20 years ago, a family I know lived in the most random old-fitted-out "multi-storey house above a shop" ever (sadly since converted to boring flats) with a weird random layout and multiple bathrooms (one leading into one of the bedrooms and another leading into the laundry room), and the kitchen had a 12 inch (or "300mm") Vent Axia T-series wall extractor fan, yes in a domestic house! I can't see why one couldn't be used in a bathroom either?
140mm 12v brushless PC fan, thermostatic speed controller, 12v psu -sorted. much quieter, more air flow and only runs when its actually needed.
Easy to replace when the bearing goes bad too! Commodity components ftw
If I did my bathroom again, I’d install a heat recovery through the wall fan.
Semi rigid ducting is the way forward 👍
Had to replace my old extraction fan as it stopped working after a couple years after a bathroom refit took the manufacturer details and found it was about £7 on ebay went to b&q a got a marly fan about £40 has been going years
1 bends equals 16m of straight equivalent? Is that just for flexi duct?
I thought it added 1m per bend.
Would this be the same if i install MVHR with a 90mm semi rigid duct for each bend?
Unfortunately you've not addressed the inline fan option which is typically quieter and more powerful such as the Manrose. Additionally this has 3 power level choices.
I used to like tractors. 🚜 Now I'm an ex-tractor fan! 😂
Nobody has designed a bathroom fan that works efficiently! Been waiting years for it to happen. Even dipsy Dyson ain't done one.
Fans in bathrooms need controlling with a humidistat!. When controlling humidity/ black mold formation dry air is the answer. We use to fit positive pressure axial fan units in loft ceiling or hallway dragging fresh dry air from outside the property that pressurised the dwelling with fresh dry air, pushing contaminated air away outside. The fan setup and running would acheive the set amount of air changes! Job done apart from regular maintenance. NU-air units.
When I was a child I used to collect anything I could get my hands on to do with tractors. I loved them. I even had a ride on one. As I've got older my interest in tractors has fallen considerably to almost zero.
I'm an ex tractor fan.
Like fighting a uphill battle. Apparently when I have the NICEIEC do our assessment for ventilation we are the only company in a huge radius. We sign off all new installs with a certificate and notification to building control.
Bloody no one does it, no one does it right it’s a joke.
Maybe add the ventilation course on to the apprenticeship course just to give some basic knowledge on the subject
Cause we are fed up being scammed and paying to work for marketing companies like the nic.... im either qualified or im not, paying to be * member* is a scam, really is. Just do what everyone else is doing, notify nothing.
@ agree with the “scheme cough cough scam” but it’s doing a course be it at a college or even at a manufacturing company it gives a better understanding of what should be done. Also using a dedicated tester to commission the fan will give you an idea if you have installed the correct unit for the space.
I have seen so so many piss poor installs for Ventilation it’s a joke. Provides me with lots of work which is good but not good for the customer. Should not be having to pay twice for dumb installers. Like I said if basic installation methods and basic regs were taught in the electrical apprenticeship course it would help with what the video is banging on about .
Half the problems I had were that builders would insist on underspecced fans and then complain when I failed their fan tests. Company told me to fudge the numbers to make them pass. I wouldn't put my name on those certs and eventually left.
My experience of UK builders/contractor's is many lack basic knowledge of ventilation principles. Here is another common mistake, fitting a bathroom extractor with a door that shuts tight. Where is the air drawing from?? Most extractor's I see are absolutely useless.
If the extractor is pumping air _out_ and the soil pipe is open vented (As all should be) chances are the main _source_ of air would be through the open end of the soil pipe, through the U-bend and out of the toilet... 🌬🚽🤮
And if the soil ventilation *isn't* all that great in a system with many toilets connected (Thinking of my mate and the vertical drain which serves his and 15 other flats) you're going to be breathing in more Hydrogen Sulphide than air... ☠
@dieseldragon6756 wouldn't you need to see bubbles in your toilet or gurgling sink if this was the case though? Not a nice thought
I always found that opening the window works much better than extractor fans.
Sadly, not all bathrooms have windows... 🍎
@dieseldragon6756 Yes, it is a bigger problem for people without windows.
The problem with that in the winter is that you’re just introducing more damp cold air into the bathroom
@@hughmarcus1 An extractor fan does the same, the air you blow out as to be replaced, or you would create a vacuum. That air as to get in from outside.
@ yes but not directly into a bathroom with all the associated condensation issues.
The best way is a proper MvHR system anyhow
A fan isn't just for condensation in a bathroom with toilet. So humidistat isn't suitable in such areas
Humidistat versions also include switch input so do cover all “problems”
@sparking2016 Once fitted a humidistat fan and it would turn off and then not restart. Turned out the heat from the dropper resistor would desiccate the sensor 🤦♂️.
Most new builds use Envirovent but don’t use the correct ducting so become useless. They also used a 10m run with kinks, so naturally water ran back down. I’ve had to switch to an in-line extract instead.
I used to be a tractor fan, but not anymore.....
Boom 💥
@@efixx I think you should have filled 'er up with diesel, *not* petrol... 🚜⛽💥😉
0:05 greenwood airvac
Always use icon 60
The video title made me think that this is some sloppy put to gether video by some guy from india, I was pleasantly surprised that this is an informative video. Maybe you should rethink making your titles more descriptive?
Aren't those static pressure graphs the wrong way around? I only did GCSE maths but surely volume is a function of pressure.
Been burnt recently. Axia Svara. Who knew constantly on trickle in ensuite. No way to turn it off and trickle isnt silent.
Forget 4” fans for bathrooms go for the 6” fans. Inline are a lot better.
Sucks the heat right out the bathroom that 100mm HOLE does warmest room in the house not no more since I fitted a fan,open the window used to work fine never ever had any mold house is 100years old.Heat Pump doesn’t supply enough heat for towel rails we are going backwards £60 spent on heating the house now and it is never above 19c.
With ducting a centrifugal fan is really needed for decent performance against back pressure. I have a loft mounted 150mm centrifugal fan reduced down to a 125mm inlet grill for bathroom. I don't see the point of these little 100mm wall mounted fans that do very little.
Interesting, thank you. Not really shocking though!?
It was shocking enough for me...But that's the price I pay for *not* isolating the lighting circuit before installing it! 🌬⚡🤣
What happened to
Fan E
Lol
😉
I think she was taking leave when this was edited... 😉
Dont buy envirovent on the basis of thr 5 year warranty. I did and when i had an issuez they declined the claim. Even though i bought brwnd new from Amazon. They claimed that wasn't an authorised reseller.
Will never buy that brand again. Hope this helps any other future customers.
Panasonic fans are quiet and Powerful
All I know about ex'tractor fans is that they had interests in agricultural vehicles at earlier stages of their lives, but they don't anymore... 😍🚜😋