As a mini split owner myself, I can honestly tell you after servicing two head units in my house that were really dirty from a few years of use, you should never put one up really high, especially above stairs, where it would be hard for the technician to service it or clean it out.
Inconvenient, yes but having service a lot of AC units that are in crawl spaces or through small hatches buried in a wall in rafters with no floor, it's fine I have a adjustable ladder that's designed for stairs. Keeping it so high up keeps it out of your visual line and that's worth it. And in Matt's case it's a party unit, so it won't get used much
@@matt45540 "And in Matt's case it's a party unit, so it won't get used much" -- didn't he say he uses it a lot in his house, and didn't he show the filter looking dirty
My house had a Frankenstein setup of separate upstairs and downstairs forced air HVACs along with the chaotic attic duct work, it was all a mess. Pulled it all out and replaced it all with 20 mini-splits across 5 outdoor condensers. The old system was wildly uneven, problem prone, and struggled to keep up in weather extremes. The new system is wondrous, complete and absolute control of every room, I have it setup so that I can have an entire condenser die not be that concerned, and most importantly capacity, compared to the old system, isn't even in the same league. It's all networked and completely controllable through automations, and despite being about 500% more capacity, electric usage dropped by 25-30%. Night and day difference, it wasn't cheap to do this by any stretch of the imagination, but I don't regret doing it for a second.
Finally, encouraging words! I'm doing the same for the same reasons in a new construction house, but only a dozen heads, two outdoor units. In the framing stage. Can you offer any tips on how to do this successfully, and avoid the pitfalls? I think I have it figured out, but I could still be blind to some things. What brand did you pick? I'm planning on Mitsubishi ceiling cassettes on the recommendation of my AC guy, and Matt himself, but there's still time to change it if I have to. I have some more questions regarding known pitfalls of mini-splits in another comment on this video, if you can check it out. Talking in person would also be amazing, but no idea how to get in touch on here.
Neither of you mention fresh air supply which is essential for long-term success of a mini-split or VRF system for good indoor air quality. How are you addressing this?
I am a broken record but maintenance, maintenance, maintenance. If you don't clean these properly they will really not perform and get nasty. I don't know how many people realize just how often they require attention. I would not go a full year forgetting about any indoor head unit etc. Much of the cleaners are intended to be used for routine maintenance. Not for something that had excessive buildup etc. I clean ours once a season so about 3 times a year. There are two in the house and one in the shop. Obviously the one in the shop is trickier.
I'm probably gonna hate life with my 12 units 😂 I'll probably have to have someone on retainer to clean them a couple times a year. I hope the comfort will make up for it.
Matt. I have a solar powered mini split that is a DC/AC combo. So during the day. Runs directly from the solar panels. And at night runs off the solar inverter which is using lithium ion phosphate batteries. So my cabin runs completely from solar with battery backup with no external power source. Everything Runs from solar… the well, clothes washer/ dryer, lights, internet, AC etc. 100% green energy!
It is true that mini-split or air-to-air systems can provide heating. However, as the temperature drops, the efficiency of the outdoor unit decreases because it needs to defrost more frequently. During the defrost cycle, no heat is delivered, and in my experience, this can take up to 15 minutes per hour in very low temperatures. Additionally, it is crucial to choose a unit that is most efficient within the typical temperature range of your outdoor environment. Different manufacturers optimize their systems for different temperature ranges. Efficiency is measured in COP (Coefficient of Performance) or SCOP (Seasonal Coefficient of Performance), which indicates how much heat the unit can produce per kWh of electricity. Ideally, you should aim for a heating ratio of at least 4.
I've been in HVAC residential service for 28 years. Mini splits if done right can work great, but once they experience some type of failure it can be difficult to locate repair parts since most of the components are proprietary and there are no universal parts. Homeowners should be aware that even though you may have a unit that is under warranty, it may take a couple of weeks for parts to arrive
please do a video about the limitations of mini splits too. Single wall mounted units no matter how large cannot condition multiple rooms, unless they are ducted to each room, or there need to be in-wall transfer fans to circulate conditioned air.
It will probably cool and heat them it just will be colder and hotter where unit is to allow for the delayed air that finally makes it was to other rooms Plus have to leave all doors open
Mini-splits by definition are not intended to heat and cool multiple spaces (with a few specific exceptions). That’s how they got the name mini-splits! Serving multiple rooms with one air handler is just a standard ducted heat pump HVAC system.
My climate gets down to -40 degrees F in northern MN. Air heat pumps don't work the best, but ground loop heat pumps still work great. Minisplits are popular because we don't need a ton of primary cooling, but when it gets down to -40 a little extra heat output or a secondary heat source using a different energy source than the main heat source can be a life saving requirement.
I'm in Japan and they are everywhere here. I have 4 in my house mostly as aux heat since I have 4 kero heaters, a heated floor and two wood stoves. I love that you can heat just the areas that you want, no central heat here. They are very reliable, one of mine that came with the house is 32 years old and runs like a champ. They are very frugal on power unless you are trying to heat when it is quite cold out. Another advantage of them is they run on a remote control so no need to go to the thermostat to change the temp. The have timers so you can have it come on in the morning before you get up or turn off an hour after you go to bed.
I built a new home 3 years ago in Chicago. I added mini-splits as supplemental Heat/AC for the bedrooms. I love it!!! My wife likes it cold, I don't. So at night, I go in my bedroom and turn on my mini-split and life is perfect. I also don't have to heat or cool the entire house overnight. The only down side is when it gets to 5 below zero, they no longer produce heat. Maybe they will improve that in the future.
As Matt says here, he uses his mini splits in ways he didn't predict. Sometimes the mini split is his MAIN source of heating/cooling, and sometimes it's not used. So my suggestion is to design a central air system (like Matt did), and then add mini splits later as necessary when you find uses for them. For example, when your duct plans fail and leave one bedroom cold, add a mini split to it, rather than starting with a mini split in every room.
Let's talk about non-myths: 1) More units is more maintenance 2) Temperature control on most systems sucks, with very wide thermostat bands 3) On some systems, like Mitsubishi, the fans run constantly, even when no heating or cooling is called for. Do folks have tips on solving these? For 3), on Mitsubishi units you have to cut a physical jumper to disable the continuous fan. Pretty nuts, but at least it's possible. Ostensibly it works that way to circulate air, so the internal temperature sensor can sense a better average temperature. But it seems pretty crazy with wall mounted thermostats. And in general... Ends up burning more power than conventional systems. I also hope the outdoor unit can get to a low enough speed to feed an indoor unit running on low speed with low heating/cooling demand. And what if it can't? I'm building a SIP house, very well air sealed, so I expect my heating and cooling demands to be generally low.
We just turned on our 5 zone Mitsubishi mini-split system in our new build. So far it's better than I expected. Ive only needed 2 of them to maintain the consistent temp in the house. We also have a Braun AI ERV it really is great.
I put a mini split in my new well insulated work shop. It's 10' off the floor, with a 17' center beam. I had to buy a new step ladder to be able to clean the filter, which I wish was designed better. I can either shop vac the filter, or wash it. But I do wish they made a "kit" to improve the filter aspect, especially since my shop gets a lot of dust, welding smoke, etc.
As a 30yr HVAC Tech, a friend from church hired me to install 6 Mini-split systems in his 4000 sq ft home, Installed perfectly, yet 5yrs later he pulled them out and had central forced air systems retrofitted... his entire house was designed for the minis. but they are only good for niche applications. IMHO
Room size air purifiers are great for a bedroom, but once you add up the cost of the machines, the electricity and especially the filters it is more economical to have a whole home air filtration solution installed in the hvac and then a room sized purifier in the bedroom of anybody with issues such as asthma for that additional boost. I personally like the reme halo led system coupled with an electronic air cleaner and a filter box large enough to provide high merv without too much pressure drop for the health of the system.
I think whole house filtration is the one thing that's making me rethink my options for our eventual retirement home. Mini-splits are great for multizone heating and cooling, but I don't want a bunch of filter boxes littered around the house. I may still use some form of mini-split, preferably with a ground-source heat pump but I still want whole house filtration. If for no other reason than being able to use bigger, cheaper, and easier to maintain air filters.
@@jl9678 I can, but for 3 bedrooms, a main living area and a crafts area/home office, that's a lot of boxes to fit in the design, a bunch of places around the house to go every time the filters need changed, and a bunch of filters that won't need changing at the same rate. I think I'd rather get a single V- or W-box in the mechanical room and just route a bunch of hoses through the second floor trusses. I probably would do a box like that for the ERV though. Those filters are expensive, tiny, and stupid.
That strategy filters the air only after it has already entered the house; it’s just a strategy for keeping your mini-split clean, not your lungs, furniture, finishes, etc. A whole house ERV system will provide great indoor air quality for your entire house.
I'm surprised the Zehnder is not enough for him to clean the air, since it's running constantly. I assume you can get a HEPA or high MERV filter in that?
Gonna put a 9K BTU unit in a travel trailer. Wouldn't do it in a house. Radiant with great insulation all the way. I'm in a northern climate. In a refit? In a minute. Custom build? Don't like blowing air hot or cold if I can avoid it.
Myth #6, mini splits are more efficient than central ducted systems. This was true several years ago when mini spits were marketing seer 30+ and conventional systems were seer 14-16. Now, the much more realistic seer2 knocked the top tier seer 38 mini splits to seer2 27. Only the very small 3/4 or 1/2 ton get that high, but most 1 ton and above are only seer2 16-20. Meanwhile the central systems have improved vastly and reaching seer2 20 and up to 23. There's no longer a good reason to use mini splits.
I can think of one or two. Since the industry has figured out outlawing Freon X ever 10-15 yrs so owners have to get new systems before it’s worn out. The other is in areas with power outages, you can run one unit for a room versus the whole house.
Ducted mini-splits, that's it! Hide the unit in a conditioned attic, crawl space or utility closet. Then you can add a fresh air ERV/HRV system such as Zehnder (or others) and I think that would be the ideal combination for fresh filtered and dehumidified air plus the most efficient heating and cooling. Thanks, Matt & Steve! PS: Please do a presentation on ducted mini-splits. Also, I have no personal experience with mini-splits, but it seems since they have a built-in fan, they'd be noisier when operating than a ducted system with an air-handler located far from the vents in the rooms. Maybe someone could comment on mini-split noise. Thanks again.
I installed a Pioneer ducted mini-split to condition a couple of rooms in my basement. I really want to like the thing, but it has one huge flaw: the temperature control is awful. Suppose it's 71 degrees in the room and you want it a little warmer, so you set the temperature (wall controller or remote, they both work the same) to 72 degrees. Nothing happens. So you set it to 73 degrees... again, nothing happens. Set it to 74 degrees and the unit comes on and starts heating. And continues, and continues... I usually get fed up and turn it off when the temp in the room hits about 80. From research on forums, I understand that that behavior is pretty typical.
@@D2O2 I could be wrong but I believe Matt has covered Zehnder and other fresh air ERV/HRV systems and has shown them connected to dehumidifiers, such as AprilAir and others. Of course dehumidifiers would more commonly go in-line with the heating/cooling ducting system.
Any erv will constantly raise humidity as it's pulling in humid air from outside and can't reject all of the moisture. So in humid climates you need a dehumidifier, or an ac system that's really good at dehum. More so than if you didn't have an erv.
@@D2O2yes if... it's less humid outside. An ERV is like opening a window, fresh air but the air heat and humidity is in the same "direction" as the outdoors.
these days pretty much everyone makes a single direction ceiling cassette like that it typ fits between joists in the ceiling. there are bigger 4 way ones too
Concealed ducted is not a mini split anymore. It might be VRF, but it's not mini. That octopus mess at 5:59 is most definitely falling into the central air category.
Actually it is considered a mini-split and is marketed as such by several manufacturers because it serves a limited area and is smaller than even the smallest whole house heat pump system. Also, VRF is not synonymous with mini-split and the vast majority of mini-splits are not installed as components of a VRF system.
On myth #3: The -20°C minimum temperature isn't even particularly low. Most manufacturers have models specifically designed for cold climates that can go much lower. My Toshiba mini-split (RAS-25) for example has a minimum temperature of -35°C (-31°F).
True to a point. But the COP when the unit is operating in that cold of an environment is 1.2-1.6. Barely more efficient than just electric resistance. If your area gets that cold it would be worth it to invest in a wood boiler and radiant floors. Then just use the heat pump for chilly days.
I have two ductless mini-splits rated down to -22F. Their heat output drops as it gets colder, though. I sized them to provide enough heat at the coldest outdoor temps I see in my area. A basic Manual J calc and a glance at the units' spec sheets made it an easy decision. I have a 12k and a 24kBtu/hr unit, so 36kBtu/hr. At 25F I expect 31 kBtu/hr from them. The variable compressor speed and variable fan speed technology is great, too. I was able to oversize my units (to meet my coldest day and hottest day needs) without causing short-cycling on normal days.
Toshiba rates their units decently. Same with Panasonic and Mitsubishi. Their cold weather performance is still decent at cold weather. Both capacity and efficiency. Do note that if you have natural gas available, it's likely cheaper to heat with below somewhere around freezing +/-5°c depending on utility rates and model.
We did one house over 4000 sq ft on one ducted 18k BTU mini split. (Design called for 12,500 BTU.) So yeah, it can be done in a whole house situation! 👍
Hmm currently building a barndo type house that I am planning on using mini splits for but the one thing I had not thought of was the air filter, don't really care what it looks like for the space and would provide plenty of heat and AC but I'm on a dirt road with lots of dust, so you may have actually talked me out of them for my application... Food for thought. Thanks for the thought.
I added a separate air filter system. It runs 24/7, whether heating cooling or nothing. Merv 16 carbon filter 20x25x5. With a dust/hair filter in front of it to keep the nice one cleaner.
Yeah, you should have a dedicated ERV system with mini-splits in a new build or you’re not going to have good indoor air quality. An older house may or may not be leaky enough to have adequate fresh air, but it’s not going to be filtered and pressure balanced regardless.
#1 Super expensive period. #2 I have a Mitsubishi i have had for 14 years. Dead now but did love it. I always changed the filters but was shocked in year four of only using for air conditioning. The blower wheel was not putting any air out or very little . I took it apart (nightmare) and was astonished at how much mold and gunk was on the blower, made me ill looking at it..I am replacing it because it worked great, but now know to clean the blower wheel more often.
my apartment manager says the new unit they installed in all the old apartment buildings is a "mini-spit" but its installed in place of the old central air unit. I think they meant central-air heatpump. either way the unit is horribly underpowered especially now that its colder. but even just barely below freezing at night and the heat drops below the setpoint by a least 2f, or 1C. the HVAC guys say the unit is working properly and just totally ignore that their install isn't actually working as a resident would want it to.
Biggest issue with mini splits is, they are absolutely useless in a basement in most of this great country. Not enough sensible heat load, and the smallest indoor unit is 7kBtu, so it doesn’t take out enough humidity and the basement stays damp and musty. (the “variable” models are bs. it’s only the condenser that is somewhat variable, in reality it only adjusts its btu output depending on how many indoor units are tied to it and currently demanding refrigerant, but each indoor unit always gets full flow. Only Mitsubishi’s top of the line model can control the refrigerant flow volume to each indoor unit). I have 4 , 5 ton condensers powering 5 indoor units each. 5, 12kBtu units, and 15, 7kBtu units. The ones on the three regular floors work fine, but still severely oversized for most of the rooms they’re in. The basement units make it nice and chilly, but leave it damp.
While it's true that a mini split doesn't dehumidify as well as a dehumidifer, no other heating/cooling system does, either. If you need a dehumidifier, get a dehumidifier
Myth Busters Matt, Steven and Brian 👍👍👍... My buddy lives in a very basic 2 X 4 uninsulated 1950's house in Southern California. He has a 4 ton HVAC system. A few years ago we installed 2 mini splits in that house, one in the master bedroom and one in the living room to ad either additional AC or primary AC depending on the time of year. Here is the BIG BENEFIT, when his 4 ton HVAC system went out, those mini splits managed to keep the interior under 80° when it was 110° outside. Multiple mini splits offer unique value in redundancy... Myths busted... Great video, thanks for sharing, blessings and Merry Christmas wishes to all..... 🙂👍
It's a lovely mini-split.......it's just in the wrong spot. When you come down the stairs it's sticking out from the wall right in your eye-line. It should have gone on the wall over the doorway at the bottom of the stairs.
I've got a Mitsubishi hyper heat system. When the temperature outside drops below 30F, the unit hardly heats at all. It spends its time defrosting as my house gets colder and colder.
I understand and agree with the need for mini splits, but what about the extra air conditioning unit heating unit plus what you have the Zender unit. Do you really need three different mechanicals to keep a space heated cooled and fresh air for the house? It seems quite a bit a lot of mechanicals being used for comfort.
That is one thing I dont get. They should build an all in one unit. I know some people have built out systems that use the same ducting but it can sometimes be a little difficult to get right. If they just built an all in one system or a system that was designed to work together that would make way more sense.
Unfortunately, you usually have to pay for additional consulting/engineering to get an all-in-one system to work properly without having unintended consequences. Most installers don’t even use a basic Manual J calculation when sizing a system; they just use rule of thumb. So to expect them to properly design and install a combined heating, ventilation, and air conditioning (and humidity control) system is asking a lot. Where I live, there are at least two HVAC contractors that have licensed engineers on staff, but they typically work only on commercial projects and really large residential projects.
Thank you for the great video, I know a little bit about these but not as much as I would like to. The other great thing with these videos is the feedback in the comments section.
"Myth 3" is not actually a myth for a lot of us. A low ambient cutout of -4 is not that low for a lot of climates. I see these going in all over in my climate - which has had winter cold spells of -30 highs for entire weeks
What about humidity control? I'd like to do mini splits in my new build but don't want to have to add ducting just for controlling humidity here in GA.
You will not be happy with a mini-split system in GA with no dedicated ERV system and dehumidification. In fact, you will almost certainly have mold growing in your walls without ducted ERV and dehumidification unless your house is really leaky in terms of air infiltration. Even then, you’ll probably grow mold behind vinyl wallpaper, pictures hanging flat on the wall, and anywhere else the walls can’t “breathe.” Of course if your house is that leaky, your electric bill will be astronomical.
Thoughts on 4/5 ton units from Mr.Cool? I need to replace my entire system and the heat is oil from 1956 and the AC from the early 2000's. The compressor is dying.
I have a Mitsu system: two 5 ton air handlers outside, 6 zones inside. Each zone has an air handler with ducts to linear diffusers. Do I have a mini split system?
How do you clean the one above the stairs? They are great for houses that are refits and additional options. They okay not great I like the flush mount ceiling, but they only cool so much so you really need good insulation vs a regular in duct system. Now my mini splits do both have regular filters but thin screen filters and. Mine get dirty all the time. And impossible to clean without removing. I know they have better tech now but .. mine look nasty. I run heap filters all over my house.
-4F heat pump?!?!?! That is incredible. I am used to heat pumps falling off at 32F. I live in Iowa and having supplemental electric heat would be phenomenal.
I am a licensed HVAC contractor in florida. Most of the standard GREE brand mini splits that i install will heat effectively down to -13F. Not that we see those temps in florida. But they are capable of it. They will also cool when outdoor temps are as low as -4F. I have a client with a couple of server rooms that need to be kept cool year round..the servers create lots of heat, meaning, even in winter when its cold outside, the server rooms still need AC cooling. Most traditional split system air conditioners will not continue cooling when the outdoor temps drop too low...not without a low ambient cooling kit put on it...which is essentially a fan cycling relay/timer/pressure tranducer...which turns the outdoor fan motor off, strategically, to keep the head pressure from dropping too low to allow the refrigeration cycle to do its thing. also of note, GREE's Ultra series mini splits can heat down to -31F outdoor ambient. Amazing.
I installed a Mitsubishi cold weather mini split in northern Wisconsin. (30 minutes from Superior) Works great down to -15° F. For colder weather we retained an existing wood stove.
I’m sorry, guys; ductless mini-splits hanging on the wall or even in ceiling cassettes are visually hideous. Ducted mini-splits are the way to go if a mini-split is your preferred option in a given situation.
This subject was touched on, but I'd like to dive into it a little. I am thinking about putting a mini split in an ADU I'm having built as the sole heating and cooling for the unit. I live in northern Idaho, where it can get down to -20 degrees Fahrenheit. Does this seem feasible? Are there units that can accommodate those low temperatures?
What are you doing for fresh air? A tight, code-compliant building envelope needs some sort of ventilation system to provide fresh air, manage CO2 levels, and filter the incoming air (bonus points if you incorporate an HRV or ERV). It’s probably not hot enough or humid enough to need dehumidification during the summer in northern Idaho. I’m guessing you just open a window at night like we do over here in Oregon.
I'm building my 4300sqft house with ceiling cassettes in every room/area. I didn't want to deal with people in different rooms being unhappy with someone else's thermostat setting. Even closing a door vs having it open greatly affects the cfm coming through a duct. Balancing registers every season sucks, plus never turns out that well. A single head in a room has no such issues. It's not that expensive. 45k for like 12 heads, two narrow outdoor units. No big deal. And saving the labor and planning headaches of running big ducts where they don't fit is nice. What am I screwing up?
Wow that's a lot of heads! Sounds like it will be energy efficient. Here in NE Kansas setting up two forced air handler systems would be about half the cost.
What you’re screwing up is not providing a dedicated, whole-house energy recovery ventilation (ERV) system for fresh, filtered air (unless you just forget to mention it). You’ll probably need dehumidification during cooling season as well depending on where you live. Presumably your existing ducted system could be modified to provide these functions. The existing ducts are way oversized, but that’s much better than being undersized and dampers could be used to balance the system. Transfer grilles and ducts in the ceilings between bedrooms and hallways can eliminate the imbalance created by opening and closing the doors.
@@MichaelJ674 Yes, I'm using a Zehnder ERV. It's pretty much a requirement anyway with tight SIP construction. It's new construction, so no ducts planned. I'm in Los Angeles, so humidity is not really an issue. Transfer grilles were a possibility, but they also transfer noise. IMO central units are not really possible to balance for many reasons,. though changing seasons, etc. And even if you could, every person's temperature requirement is different. Zoning with a ton of dampers was also floated, but I was told those systems don't work well, either. But I appreciate all input.
If you can hide the box on the inside that's great. it's a lot easier to do on a new build where you can plan. if you have a space that already exists it's hard to find a spot to put it. they are ugly, and take up space...
I am going to admit it: I was a little shocked to see the in-room air cleaner in the bedroom. You've got a Zehnder - the Ferrari la Ferrari of ERV's - and that you still needed supplemental filtration kind of rocked me back on my heels.
To be fair, Zehnder is advertised as an ERV, and it is. Zehnder is NOT advertised as a HEPA filter for every square inch of air in the home. If you want to turn your house into a wind tunnel with ducts and massive filters like a nuclear silo, you can absolutely do that, but it's a separate thing from an ERV.
My 1500 sq ft home in VT is heated this winter with only two mini splits. I will say that I would not install one in a bedroom again. The sounds of the refrigerant in the lines running into the unit when its defrosting is a bit annoying.
I’ve had both in house builds. Prefer forced air, more pleasant for the entire space and smaller bathrooms etc. But mini splits are great for garages or additional capacity in big rooms…esp if you properly pair them with an ERV for fresh air
I don't know what's worse putting the indoor unit in a crawl space and ducting it or mounting it 10 ft above the stairs good luck servicing it. I'm not
UV light kits keep down microbial growth on the blower wheels. I prefer Mitsubishi units for their servicablity. Surge protectors help save expensive boards too. 25 yr service tech
Great tips! I'm planning on 12 Mitsubishi ceiling cassettes. Are these UV light kits aftermarket? Whole house surge protector? Any other tips for making such a system work well?
I think they look great. Living outside the US as a kid for several years these were considered statue symbols. I proudly placed mine front and central like a family portrait for all to see. Btw Its my only source of hear in the cold New England whether.
So you built a custom house, and instead of designing an appropriate ducted system you added a mini split? FFS. If you need a “boost” add automatic dampers in your conduits to make independent zones
I was told that zoning central air with dampers doesn't end up working very well. Do you have experience to the contrary? I would need like 10-12 zones.
You design a custom home with a light well washing the double height wall with daylight and then you put an ugly AF mini-split head right at eye level as you come down the stairs. Obvious conclusion: the mini-split manufacturer sponsored the mechanical system video during Matt’s house build.
He spent how much money on that Ferrari of an erv (his words) and spent so much time talking about all of his amazing air filtration. But he still has a stand-alone unit for air filtration in each bedroom?
The whole installation on that wall is hideous. Why would you wash the wall with daylight from above and then put an ugly mini-split head right at eye level coming down the stairs and air return grilles on either side. I think he reinforced myth #1 rather than debunking it. The view at 7:00 is so bad; I would have been too embarrassed to even show that clip. And then how Steve can stand there with a straight face as an architect is beyond me. And then you cut to the bedroom where you’ve had to add one of those useless air recirculating units in each bedroom because your expensive ERV system is inadequate… I lost a lot of respect for you guys with this video.
Maybe give a little more background info next time because minis have been invented for heating and are more efficient in that mode than in cooling so northern climates can use them. DNO - DO NOT OVERSIZE! Mitsu has a paper on that dated 10+ years. Those units are not great for dehumidification (90/10 SHR) and oversizing is bad. I hear so many contractors say that it’s ok because they ramp down to 20% ish of capacity but they don’t understand the tech behind all that. Manual J!
What's wrong with ramping down? If a one ton head is running at 50% speed, it would be the same as a half ton unit for dehumidification. What am I missing?
Having a mitsubishi mini split in east texas is no fun. No matter how much you clean the filters, the fan coil gets dirty and i have to take it apart every 6 months because of dust and mold 😒. Thats the reason im doing a traditional heat pump hvac system in my new house build.
Right?! I was all into mini splits until I watched a video on how to clean them. Huge pain and that's just for the wall mounted ones. The recessed ones are even harder to clean. Imagine doing all that for four different mini splits twice a year!
The minisplit floor-based units look a lot better. Having those where you use them almost exclusively for heating is nice, too, as you are heating across the floor. I just think they look ugly when they're sitting on a wall. They could make them a lot nicer looking by making them black or stainless or something other than just off-white.
This video is right is right on, mini splits are great for heating and cooling. However they are a maintenance nightmare so if you like mold blown around your house and $400 to $600 maintenance bills per year buy a mini splits, you'll love them! My experience was that any energy savings you have are blown on astronomical annual maintenance bills. If you have mini splits you will have poor indoor air quality mold mildew dust.
IQ-AIR!!! Dude If your going to do stand-alone filtration there’s nothing that beats “Swiss Made” I can’t believe you don’t know about IQ-Air, not crazy expensive and Hospitals use them. They can remove the smallest particles known to man. I have sleep apnea and I wear a blood O2 monitor to bed and my blood oxygen levels are 4-5 points higher when these are on. I’ve had air filters my whole life and nothing compares to these. Did you guys know we are all breathing microplastics? I just found that out. There’s so many things in our environment that are trying to kill us and we find out about more everyday. That’s why I bought the filter that can filter down to the smallest possible molecule. Or in the filter world they call that a micron and these go lower than 1 micron. That way only O2 can fit through the holes. It’s technically called air scrubbing or air washing when you get that low on the scale. Also IqAir last 2-4 years because there’s so much surface on thier filters. If you pulled one apart and laid all the filter area flat it’d be the size of a car versus the next best, Dyson which had way small filter contact surface area like 4x4 feet. Can’t believe that much can be fold into those tiny machines
I've owned a large HVAC company that does thousands of installs per year. Ductless are great for bonus rooms or garages, but traditional systems are better 99% of the time. Main reason are that ductless are a pain to service and in my experience have a much higher chance of failure (the pumps they use are often loud and annoying). Additionally, the techs cannot have the parts on them to easily fix while there like they can for regular split systems. In most cases splits systems are less money too. These ducted "mini-split" systems or the ones with multiple interior heads are very expensive, and do not work the way people think. You cannot heat and cool each room/zone simultaneously without upgrading to even more advanced systems that are extremely expensive. Simply not practical. PS -- If you are needed ductless due to some reason that a regular split will not work, Id recommend you stick with main brands like Daikon and Mitsubishi that offer legit warranties, and go to a ceiling cassette that looks much cleaner and has the pump already built in.
Tbh yea they are hideous. But also, why not just put in a pizza box and duct a single room with it? Also makes sure everyone's happy with their own zone. Edit: nvm he actually did this XD
You can run several ducted heads off one outdoor unit, so you can still get better zoning. You have the option to mix and match tonnages and form factors. I opted for all ceiling cassettes for simplicity and optimal zoning.
Agree, a mini split does the heat/cold transfer directly with the air in the room that they intend to heat/cool down. When you add ducts and do the heat/cool down another place it’s just a normal ventilation, size doesn’t matter
Since you didn't mention it as a Myth... From observation of several TH-cam Videos.. Mini-splits are difficult to clean. Apparently, the mini-split manufacturers do not make them easy to disassemble for cleaning and have many plastic wearing parts (that wear or are easily damaged when disassembled, eg. metal screws into plastic). Additionally, cleaning is recommended 1-2 times per year. Are these thing really designed for a 20 year lifespan?
As a mini split owner myself, I can honestly tell you after servicing two head units in my house that were really dirty from a few years of use, you should never put one up really high, especially above stairs, where it would be hard for the technician to service it or clean it out.
Exactly
Good advise, thanks
Inconvenient, yes but having service a lot of AC units that are in crawl spaces or through small hatches buried in a wall in rafters with no floor, it's fine I have a adjustable ladder that's designed for stairs. Keeping it so high up keeps it out of your visual line and that's worth it. And in Matt's case it's a party unit, so it won't get used much
It's really not a big deal. A ladder with independently adjustable legs is all you need.
@@matt45540 "And in Matt's case it's a party unit, so it won't get used much" -- didn't he say he uses it a lot in his house, and didn't he show the filter looking dirty
My house had a Frankenstein setup of separate upstairs and downstairs forced air HVACs along with the chaotic attic duct work, it was all a mess. Pulled it all out and replaced it all with 20 mini-splits across 5 outdoor condensers. The old system was wildly uneven, problem prone, and struggled to keep up in weather extremes. The new system is wondrous, complete and absolute control of every room, I have it setup so that I can have an entire condenser die not be that concerned, and most importantly capacity, compared to the old system, isn't even in the same league. It's all networked and completely controllable through automations, and despite being about 500% more capacity, electric usage dropped by 25-30%.
Night and day difference, it wasn't cheap to do this by any stretch of the imagination, but I don't regret doing it for a second.
Finally, encouraging words! I'm doing the same for the same reasons in a new construction house, but only a dozen heads, two outdoor units. In the framing stage. Can you offer any tips on how to do this successfully, and avoid the pitfalls? I think I have it figured out, but I could still be blind to some things. What brand did you pick? I'm planning on Mitsubishi ceiling cassettes on the recommendation of my AC guy, and Matt himself, but there's still time to change it if I have to. I have some more questions regarding known pitfalls of mini-splits in another comment on this video, if you can check it out. Talking in person would also be amazing, but no idea how to get in touch on here.
Neither of you mention fresh air supply which is essential for long-term success of a mini-split or VRF system for good indoor air quality. How are you addressing this?
@@MichaelJ674 Zehnder for me in SoCal.
I am a broken record but maintenance, maintenance, maintenance. If you don't clean these properly they will really not perform and get nasty. I don't know how many people realize just how often they require attention. I would not go a full year forgetting about any indoor head unit etc. Much of the cleaners are intended to be used for routine maintenance. Not for something that had excessive buildup etc. I clean ours once a season so about 3 times a year. There are two in the house and one in the shop. Obviously the one in the shop is trickier.
I'm probably gonna hate life with my 12 units 😂 I'll probably have to have someone on retainer to clean them a couple times a year. I hope the comfort will make up for it.
Never install where they look good. Install where you can service and wash it out and clean filter
That’s a false choice; good design will accomplish both or you’ve failed to meet your minimum design requirements.
Best install I ever saw, had a filter 'Box' above the head to keep the unit clean. Worked.
Find out how easy it is to remove, or access the blower wheel (FAN) before you buy, install.
WISE COMMENT LOL
Matt. I have a solar powered mini split that is a DC/AC combo. So during the day. Runs directly from the solar panels. And at night runs off the solar inverter which is using lithium ion phosphate batteries. So my cabin runs completely from solar with battery backup with no external power source. Everything Runs from solar… the well, clothes washer/ dryer, lights, internet, AC etc. 100% green energy!
It is true that mini-split or air-to-air systems can provide heating. However, as the temperature drops, the efficiency of the outdoor unit decreases because it needs to defrost more frequently. During the defrost cycle, no heat is delivered, and in my experience, this can take up to 15 minutes per hour in very low temperatures.
Additionally, it is crucial to choose a unit that is most efficient within the typical temperature range of your outdoor environment. Different manufacturers optimize their systems for different temperature ranges. Efficiency is measured in COP (Coefficient of Performance) or SCOP (Seasonal Coefficient of Performance), which indicates how much heat the unit can produce per kWh of electricity. Ideally, you should aim for a heating ratio of at least 4.
It’s always bothered me that Matt has one in the middle of his staircase even after a complete renovation.
I dont understand either- doing all that work and having a wall unit in the stairs and one on the kitchen ceiling. Cmon.
Yes! It didn't need to be that way and it IS hideous. Mini Split head = modern window unit
I think he did it slightly on purpose to “break the stigma” of minisplits in the USA
Ducted mini split is great, ceiling mount is ok, wall mount is shit!
@MustardMade I think he might have reinforced it.
I've been in HVAC residential service for 28 years. Mini splits if done right can work great, but once they experience some type of failure it can be difficult to locate repair parts since most of the components are proprietary and there are no universal parts. Homeowners should be aware that even though you may have a unit that is under warranty, it may take a couple of weeks for parts to arrive
Any brands/models you would recommend kind sir?
please do a video about the limitations of mini splits too. Single wall mounted units no matter how large cannot condition multiple rooms, unless they are ducted to each room, or there need to be in-wall transfer fans to circulate conditioned air.
It will probably cool and heat them it just will be colder and hotter where unit is to allow for the delayed air that finally makes it was to other rooms
Plus have to leave all doors open
Mini-splits by definition are not intended to heat and cool multiple spaces (with a few specific exceptions). That’s how they got the name mini-splits! Serving multiple rooms with one air handler is just a standard ducted heat pump HVAC system.
2:36 that is called a ceiling cassette.
My climate gets down to -40 degrees F in northern MN. Air heat pumps don't work the best, but ground loop heat pumps still work great. Minisplits are popular because we don't need a ton of primary cooling, but when it gets down to -40 a little extra heat output or a secondary heat source using a different energy source than the main heat source can be a life saving requirement.
You can also build a 4 inch pleated filter box to accept Aprilaire filters.
I am surprised with everything that you did in the garage that you don't have an insulated garage door!
I'm in Japan and they are everywhere here. I have 4 in my house mostly as aux heat since I have 4 kero heaters, a heated floor and two wood stoves. I love that you can heat just the areas that you want, no central heat here. They are very reliable, one of mine that came with the house is 32 years old and runs like a champ. They are very frugal on power unless you are trying to heat when it is quite cold out. Another advantage of them is they run on a remote control so no need to go to the thermostat to change the temp. The have timers so you can have it come on in the morning before you get up or turn off an hour after you go to bed.
I built a new home 3 years ago in Chicago. I added mini-splits as supplemental Heat/AC for the bedrooms. I love it!!! My wife likes it cold, I don't. So at night, I go in my bedroom and turn on my mini-split and life is perfect. I also don't have to heat or cool the entire house overnight. The only down side is when it gets to 5 below zero, they no longer produce heat. Maybe they will improve that in the future.
Imagine designing a house with a complex Mechanical
System and you still need standalone HEPA filters in the bedrooms for air quality. 🤦♂️
Imagine having a daughter with asthma and not going the extra mile to give her the cleanest air possible, even if it's overkill ...
Standard minis don't even have an air filter ,just a screen
As Matt says here, he uses his mini splits in ways he didn't predict. Sometimes the mini split is his MAIN source of heating/cooling, and sometimes it's not used. So my suggestion is to design a central air system (like Matt did), and then add mini splits later as necessary when you find uses for them. For example, when your duct plans fail and leave one bedroom cold, add a mini split to it, rather than starting with a mini split in every room.
Let's talk about non-myths:
1) More units is more maintenance
2) Temperature control on most systems sucks, with very wide thermostat bands
3) On some systems, like Mitsubishi, the fans run constantly, even when no heating or cooling is called for.
Do folks have tips on solving these?
For 3), on Mitsubishi units you have to cut a physical jumper to disable the continuous fan. Pretty nuts, but at least it's possible. Ostensibly it works that way to circulate air, so the internal temperature sensor can sense a better average temperature. But it seems pretty crazy with wall mounted thermostats. And in general... Ends up burning more power than conventional systems.
I also hope the outdoor unit can get to a low enough speed to feed an indoor unit running on low speed with low heating/cooling demand. And what if it can't?
I'm building a SIP house, very well air sealed, so I expect my heating and cooling demands to be generally low.
We just turned on our 5 zone Mitsubishi mini-split system in our new build. So far it's better than I expected. Ive only needed 2 of them to maintain the consistent temp in the house. We also have a Braun AI ERV it really is great.
The ERV is key for making the whole system work in terms of IAQ. That’s the piece that a lot of people leave out. Kudos for doing it right!
I'm planning on a 12 head Mitsubishi system. Any tips you can offer? Anything annoying about the system?
I put a mini split in my new well insulated work shop. It's 10' off the floor, with a 17' center beam. I had to buy a new step ladder to be able to clean the filter, which I wish was designed better. I can either shop vac the filter, or wash it. But I do wish they made a "kit" to improve the filter aspect, especially since my shop gets a lot of dust, welding smoke, etc.
The FarmCraft 101 channel had a great video where he built a filter box around his mini split in his shop.
As a 30yr HVAC Tech, a friend from church hired me to install 6 Mini-split systems in his 4000 sq ft home, Installed perfectly, yet 5yrs later he pulled them out and had central forced air systems retrofitted... his entire house was designed for the minis. but they are only good for niche applications. IMHO
That's not encouraging, since I'm doing the same with about 12 units :D Can you be specific about the deal breakers?
Love my Mr Cool Universal in northern Mn. It just works, and is cheap for winterizing the house and keeping it at 55F through the winter.
Thanks guys. Merry Christmas to you. 🎄🎄
Room size air purifiers are great for a bedroom, but once you add up the cost of the machines, the electricity and especially the filters it is more economical to have a whole home air filtration solution installed in the hvac and then a room sized purifier in the bedroom of anybody with issues such as asthma for that additional boost. I personally like the reme halo led system coupled with an electronic air cleaner and a filter box large enough to provide high merv without too much pressure drop for the health of the system.
I think whole house filtration is the one thing that's making me rethink my options for our eventual retirement home. Mini-splits are great for multizone heating and cooling, but I don't want a bunch of filter boxes littered around the house. I may still use some form of mini-split, preferably with a ground-source heat pump but I still want whole house filtration. If for no other reason than being able to use bigger, cheaper, and easier to maintain air filters.
You can use a ducted mini split and put a huge merv 13 filter ahead of it if you want
@@jl9678 I can, but for 3 bedrooms, a main living area and a crafts area/home office, that's a lot of boxes to fit in the design, a bunch of places around the house to go every time the filters need changed, and a bunch of filters that won't need changing at the same rate. I think I'd rather get a single V- or W-box in the mechanical room and just route a bunch of hoses through the second floor trusses. I probably would do a box like that for the ERV though. Those filters are expensive, tiny, and stupid.
That strategy filters the air only after it has already entered the house; it’s just a strategy for keeping your mini-split clean, not your lungs, furniture, finishes, etc. A whole house ERV system will provide great indoor air quality for your entire house.
@@MichaelJ674 As I said above, an ERV would probably (extremely likely) also be in the mix
That filtration thing blows this up, I’d say dealbreaker. Since this is about new builds, it seems lazy not to design it for forced air.
I'm surprised the Zehnder is not enough for him to clean the air, since it's running constantly. I assume you can get a HEPA or high MERV filter in that?
The ducted units can have a standard air filter and not a screen.
Thanks for the video!!
Gonna put a 9K BTU unit in a travel trailer. Wouldn't do it in a house. Radiant with great insulation all the way. I'm in a northern climate. In a refit? In a minute. Custom build? Don't like blowing air hot or cold if I can avoid it.
Great video. You got me with the Christmas stockings on the stairwell. Big smiles.
Myth #6, mini splits are more efficient than central ducted systems. This was true several years ago when mini spits were marketing seer 30+ and conventional systems were seer 14-16. Now, the much more realistic seer2 knocked the top tier seer 38 mini splits to seer2 27. Only the very small 3/4 or 1/2 ton get that high, but most 1 ton and above are only seer2 16-20. Meanwhile the central systems have improved vastly and reaching seer2 20 and up to 23. There's no longer a good reason to use mini splits.
I can think of one or two. Since the industry has figured out outlawing Freon X ever 10-15 yrs so owners have to get new systems before it’s worn out. The other is in areas with power outages, you can run one unit for a room versus the whole house.
What are you trying to say, you save more money with seer 16 than with seer 27?
Ducted mini-splits, that's it! Hide the unit in a conditioned attic, crawl space or utility closet. Then you can add a fresh air ERV/HRV system such as Zehnder (or others) and I think that would be the ideal combination for fresh filtered and dehumidified air plus the most efficient heating and cooling. Thanks, Matt & Steve! PS: Please do a presentation on ducted mini-splits. Also, I have no personal experience with mini-splits, but it seems since they have a built-in fan, they'd be noisier when operating than a ducted system with an air-handler located far from the vents in the rooms. Maybe someone could comment on mini-split noise. Thanks again.
I installed a Pioneer ducted mini-split to condition a couple of rooms in my basement. I really want to like the thing, but it has one huge flaw: the temperature control is awful. Suppose it's 71 degrees in the room and you want it a little warmer, so you set the temperature (wall controller or remote, they both work the same) to 72 degrees. Nothing happens. So you set it to 73 degrees... again, nothing happens. Set it to 74 degrees and the unit comes on and starts heating. And continues, and continues... I usually get fed up and turn it off when the temp in the room hits about 80. From research on forums, I understand that that behavior is pretty typical.
Does a zehnder unit provide any real dehumidication?
@@D2O2 I could be wrong but I believe Matt has covered Zehnder and other fresh air ERV/HRV systems and has shown them connected to dehumidifiers, such as AprilAir and others. Of course dehumidifiers would more commonly go in-line with the heating/cooling ducting system.
Any erv will constantly raise humidity as it's pulling in humid air from outside and can't reject all of the moisture. So in humid climates you need a dehumidifier, or an ac system that's really good at dehum. More so than if you didn't have an erv.
@@D2O2yes if... it's less humid outside. An ERV is like opening a window, fresh air but the air heat and humidity is in the same "direction" as the outdoors.
4:15 here's an idea.... Build the house right. Insulate and hire a duct designer and make sure the installer is flowing it.
What do you mean by “flowing it”?
@@MichaelJ674*following*
Hello Matt and Steve, what make and model is the ceiling mounted unit you showed in your kitchen?
these days pretty much everyone makes a single direction ceiling cassette like that it typ fits between joists in the ceiling. there are bigger 4 way ones too
Great video Matt!
Off the subject: What wood did you use on your kitchen ceiling.
Exactly. I had to pause it several times
Concealed ducted is not a mini split anymore. It might be VRF, but it's not mini.
That octopus mess at 5:59 is most definitely falling into the central air category.
Actually it is considered a mini-split and is marketed as such by several manufacturers because it serves a limited area and is smaller than even the smallest whole house heat pump system. Also, VRF is not synonymous with mini-split and the vast majority of mini-splits are not installed as components of a VRF system.
On myth #3: The -20°C minimum temperature isn't even particularly low. Most manufacturers have models specifically designed for cold climates that can go much lower. My Toshiba mini-split (RAS-25) for example has a minimum temperature of -35°C (-31°F).
True to a point. But the COP when the unit is operating in that cold of an environment is 1.2-1.6. Barely more efficient than just electric resistance. If your area gets that cold it would be worth it to invest in a wood boiler and radiant floors. Then just use the heat pump for chilly days.
I have two ductless mini-splits rated down to -22F. Their heat output drops as it gets colder, though. I sized them to provide enough heat at the coldest outdoor temps I see in my area. A basic Manual J calc and a glance at the units' spec sheets made it an easy decision. I have a 12k and a 24kBtu/hr unit, so 36kBtu/hr. At 25F I expect 31 kBtu/hr from them.
The variable compressor speed and variable fan speed technology is great, too. I was able to oversize my units (to meet my coldest day and hottest day needs) without causing short-cycling on normal days.
I switch to the boiler @25f. Older house though, little to no wall insulation.
25°f....balmy. Sweater weather.
Toshiba rates their units decently. Same with Panasonic and Mitsubishi. Their cold weather performance is still decent at cold weather. Both capacity and efficiency. Do note that if you have natural gas available, it's likely cheaper to heat with below somewhere around freezing +/-5°c depending on utility rates and model.
We did one house over 4000 sq ft on one ducted 18k BTU mini split. (Design called for 12,500 BTU.) So yeah, it can be done in a whole house situation! 👍
Hmm currently building a barndo type house that I am planning on using mini splits for but the one thing I had not thought of was the air filter, don't really care what it looks like for the space and would provide plenty of heat and AC but I'm on a dirt road with lots of dust, so you may have actually talked me out of them for my application... Food for thought. Thanks for the thought.
I added a separate air filter system. It runs 24/7, whether heating cooling or nothing. Merv 16 carbon filter 20x25x5. With a dust/hair filter in front of it to keep the nice one cleaner.
Yeah, you should have a dedicated ERV system with mini-splits in a new build or you’re not going to have good indoor air quality. An older house may or may not be leaky enough to have adequate fresh air, but it’s not going to be filtered and pressure balanced regardless.
#1 Super expensive period. #2 I have a Mitsubishi i have had for 14 years. Dead now but did love it. I always changed the filters but was shocked in year four of only using for air conditioning. The blower wheel was not putting any air out or very little . I took it apart (nightmare) and was astonished at how much mold and gunk was on the blower, made me ill looking at it..I am replacing it because it worked great, but now know to clean the blower wheel more often.
my apartment manager says the new unit they installed in all the old apartment buildings is a "mini-spit" but its installed in place of the old central air unit.
I think they meant central-air heatpump. either way the unit is horribly underpowered especially now that its colder. but even just barely below freezing at night and the heat drops below the setpoint by a least 2f, or 1C. the HVAC guys say the unit is working properly and just totally ignore that their install isn't actually working as a resident would want it to.
Biggest issue with mini splits is, they are absolutely useless in a basement in most of this great country. Not enough sensible heat load, and the smallest indoor unit is 7kBtu, so it doesn’t take out enough humidity and the basement stays damp and musty. (the “variable” models are bs. it’s only the condenser that is somewhat variable, in reality it only adjusts its btu output depending on how many indoor units are tied to it and currently demanding refrigerant, but each indoor unit always gets full flow. Only Mitsubishi’s top of the line model can control the refrigerant flow volume to each indoor unit). I have 4 , 5 ton condensers powering 5 indoor units each. 5, 12kBtu units, and 15, 7kBtu units. The ones on the three regular floors work fine, but still severely oversized for most of the rooms they’re in. The basement units make it nice and chilly, but leave it damp.
While it's true that a mini split doesn't dehumidify as well as a dehumidifer, no other heating/cooling system does, either. If you need a dehumidifier, get a dehumidifier
*Matt, those monsters in your stairwell & on your kitchen ceiling are HIDEOUS...*
His house and he doesn't think they are.
He’s wrong, then 😂😂😂
What Brand and model is that air purifier you are using? I have been looking for a good one.
Myth Busters Matt, Steven and Brian 👍👍👍... My buddy lives in a very basic 2 X 4 uninsulated 1950's house in Southern California. He has a 4 ton HVAC system. A few years ago we installed 2 mini splits in that house, one in the master bedroom and one in the living room to ad either additional AC or primary AC depending on the time of year. Here is the BIG BENEFIT, when his 4 ton HVAC system went out, those mini splits managed to keep the interior under 80° when it was 110° outside. Multiple mini splits offer unique value in redundancy... Myths busted... Great video, thanks for sharing, blessings and Merry Christmas wishes to all..... 🙂👍
That mini split near the stove is gonna be so greasy. Even with a super vent hood, some grease escapes during deglazing.
It's a lovely mini-split.......it's just in the wrong spot. When you come down the stairs it's sticking out from the wall right in your eye-line. It should have gone on the wall over the doorway at the bottom of the stairs.
Should have been ducted so you don’t have to look at the hideous thing (that’s not a myth 😁).
Mini splits make up for a lot of "ugly" with a much smaller repair bill.
I've got a Mitsubishi hyper heat system. When the temperature outside drops below 30F, the unit hardly heats at all. It spends its time defrosting as my house gets colder and colder.
I understand and agree with the need for mini splits, but what about the extra air conditioning unit heating unit plus what you have the Zender unit. Do you really need three different mechanicals to keep a space heated cooled and fresh air for the house? It seems quite a bit a lot of mechanicals being used for comfort.
That is one thing I dont get. They should build an all in one unit. I know some people have built out systems that use the same ducting but it can sometimes be a little difficult to get right. If they just built an all in one system or a system that was designed to work together that would make way more sense.
Unfortunately, you usually have to pay for additional consulting/engineering to get an all-in-one system to work properly without having unintended consequences. Most installers don’t even use a basic Manual J calculation when sizing a system; they just use rule of thumb. So to expect them to properly design and install a combined heating, ventilation, and air conditioning (and humidity control) system is asking a lot. Where I live, there are at least two HVAC contractors that have licensed engineers on staff, but they typically work only on commercial projects and really large residential projects.
Thank you for the great video, I know a little bit about these but not as much as I would like to. The other great thing with these videos is the feedback in the comments section.
I expect a new subdivision to soon be all mini splits.
Do folks have issues with condensate lines on ceiling cassettes?
"Myth 3" is not actually a myth for a lot of us. A low ambient cutout of -4 is not that low for a lot of climates. I see these going in all over in my climate - which has had winter cold spells of -30 highs for entire weeks
I think some units go lower, and have resistive heating elements for backup. That's probably what you see going in.
Matt - who installed your kitchen ceiling - looks great and would like to have similar work done - thank you for all the great videos and advice
I love mopping up ours every couple months because the condensation doesn't pump properly.
What about humidity control? I'd like to do mini splits in my new build but don't want to have to add ducting just for controlling humidity here in GA.
That would be dealt with by an HRV/ERV with de-humidification abilities. You will need ducts for your fresh air anyways
You will not be happy with a mini-split system in GA with no dedicated ERV system and dehumidification. In fact, you will almost certainly have mold growing in your walls without ducted ERV and dehumidification unless your house is really leaky in terms of air infiltration. Even then, you’ll probably grow mold behind vinyl wallpaper, pictures hanging flat on the wall, and anywhere else the walls can’t “breathe.” Of course if your house is that leaky, your electric bill will be astronomical.
Thoughts on 4/5 ton units from Mr.Cool? I need to replace my entire system and the heat is oil from 1956 and the AC from the early 2000's. The compressor is dying.
I have a Mitsu system: two 5 ton air handlers outside, 6 zones inside. Each zone has an air handler with ducts to linear diffusers. Do I have a mini split system?
Yes, you do. It's not central air.
Is it working well?
How do you clean the one above the stairs? They are great for houses that are refits and additional options. They okay not great I like the flush mount ceiling, but they only cool so much so you really need good insulation vs a regular in duct system.
Now my mini splits do both have regular filters but thin screen filters and. Mine get dirty all the time. And impossible to clean without removing. I know they have better tech now but .. mine look nasty. I run heap filters all over my house.
Why point out a -4F one when up here in 'the north' we've got -40f ones?
It's currently 2f out and my Mr. Cool is keeping the house warm just fine.
-4F heat pump?!?!?! That is incredible. I am used to heat pumps falling off at 32F. I live in Iowa and having supplemental electric heat would be phenomenal.
I have a Lennox unit that is rated down to -22°F.
Somehow, it was still operating at -35°F last winter in Montana. 😮
I am a licensed HVAC contractor in florida. Most of the standard GREE brand mini splits that i install will heat effectively down to -13F. Not that we see those temps in florida. But they are capable of it. They will also cool when outdoor temps are as low as -4F. I have a client with a couple of server rooms that need to be kept cool year round..the servers create lots of heat, meaning, even in winter when its cold outside, the server rooms still need AC cooling. Most traditional split system air conditioners will not continue cooling when the outdoor temps drop too low...not without a low ambient cooling kit put on it...which is essentially a fan cycling relay/timer/pressure tranducer...which turns the outdoor fan motor off, strategically, to keep the head pressure from dropping too low to allow the refrigeration cycle to do its thing.
also of note, GREE's Ultra series mini splits can heat down to -31F outdoor ambient. Amazing.
I installed a Mitsubishi cold weather mini split in northern Wisconsin. (30 minutes from Superior) Works great down to -15° F. For colder weather we retained an existing wood stove.
Minus Four is NOT a "Cold Climate" 🥶
What air filter is that in the bedroom?
What about condensation draining? Wanting to put one in my garage. Do I need a drain?
Yes, unless you live somewhere with a very low dew point
They all have condensate lines no matter where you live.
I’m sorry, guys; ductless mini-splits hanging on the wall or even in ceiling cassettes are visually hideous. Ducted mini-splits are the way to go if a mini-split is your preferred option in a given situation.
This subject was touched on, but I'd like to dive into it a little. I am thinking about putting a mini split in an ADU I'm having built as the sole heating and cooling for the unit. I live in northern Idaho, where it can get down to -20 degrees Fahrenheit. Does this seem feasible? Are there units that can accommodate those low temperatures?
What are you doing for fresh air? A tight, code-compliant building envelope needs some sort of ventilation system to provide fresh air, manage CO2 levels, and filter the incoming air (bonus points if you incorporate an HRV or ERV). It’s probably not hot enough or humid enough to need dehumidification during the summer in northern Idaho. I’m guessing you just open a window at night like we do over here in Oregon.
Yes, you can find units that go lower, especially with backup heating elements.
I'm building my 4300sqft house with ceiling cassettes in every room/area. I didn't want to deal with people in different rooms being unhappy with someone else's thermostat setting. Even closing a door vs having it open greatly affects the cfm coming through a duct. Balancing registers every season sucks, plus never turns out that well. A single head in a room has no such issues. It's not that expensive. 45k for like 12 heads, two narrow outdoor units. No big deal. And saving the labor and planning headaches of running big ducts where they don't fit is nice.
What am I screwing up?
Wow that's a lot of heads! Sounds like it will be energy efficient. Here in NE Kansas setting up two forced air handler systems would be about half the cost.
What you’re screwing up is not providing a dedicated, whole-house energy recovery ventilation (ERV) system for fresh, filtered air (unless you just forget to mention it). You’ll probably need dehumidification during cooling season as well depending on where you live. Presumably your existing ducted system could be modified to provide these functions. The existing ducts are way oversized, but that’s much better than being undersized and dampers could be used to balance the system. Transfer grilles and ducts in the ceilings between bedrooms and hallways can eliminate the imbalance created by opening and closing the doors.
@@MichaelJ674 Yes, I'm using a Zehnder ERV. It's pretty much a requirement anyway with tight SIP construction. It's new construction, so no ducts planned. I'm in Los Angeles, so humidity is not really an issue.
Transfer grilles were a possibility, but they also transfer noise. IMO central units are not really possible to balance for many reasons,. though changing seasons, etc. And even if you could, every person's temperature requirement is different. Zoning with a ton of dampers was also floated, but I was told those systems don't work well, either. But I appreciate all input.
If you can hide the box on the inside that's great. it's a lot easier to do on a new build where you can plan. if you have a space that already exists it's hard to find a spot to put it. they are ugly, and take up space...
I am going to admit it: I was a little shocked to see the in-room air cleaner in the bedroom. You've got a Zehnder - the Ferrari la Ferrari of ERV's - and that you still needed supplemental filtration kind of rocked me back on my heels.
Couldn’t agree more. That’s a major fail.
To be fair, Zehnder is advertised as an ERV, and it is. Zehnder is NOT advertised as a HEPA filter for every square inch of air in the home. If you want to turn your house into a wind tunnel with ducts and massive filters like a nuclear silo, you can absolutely do that, but it's a separate thing from an ERV.
Who sizes the unit for you?
I like these info shows... they give a person effective and cost saving idea's.. and know how
Ish…
My mini split is amazing. 0 degrees Fahrenheit keeps pumping out the heat. During hot humid MidWest summers nice and cool 🆒
Just go from 9’ to 8’ hide a pancake unit there.😂
My 1500 sq ft home in VT is heated this winter with only two mini splits. I will say that I would not install one in a bedroom again. The sounds of the refrigerant in the lines running into the unit when its defrosting is a bit annoying.
If a mini-split can be ducted and serve an entire house, at what point is it not a “mini” anymore, and we should just call it what it is, a heat pump?
I’ve had both in house builds. Prefer forced air, more pleasant for the entire space and smaller bathrooms etc.
But mini splits are great for garages or additional capacity in big rooms…esp if you properly pair them with an ERV for fresh air
Yay! Someone with functioning brain cells!! Cheers, @tjhva.
Nice.
I don't know what's worse putting the indoor unit in a crawl space and ducting it or mounting it 10 ft above the stairs good luck servicing it. I'm not
Well if it gets below 4° below zero it's no longer a myth.
UV light kits keep down microbial growth on the blower wheels. I prefer Mitsubishi units for their servicablity. Surge protectors help save expensive boards too. 25 yr service tech
Great tips! I'm planning on 12 Mitsubishi ceiling cassettes. Are these UV light kits aftermarket? Whole house surge protector? Any other tips for making such a system work well?
I think they look great. Living outside the US as a kid for several years these were considered statue symbols. I proudly placed mine front and central like a family portrait for all to see. Btw Its my only source of hear in the cold New England whether.
So you built a custom house, and instead of designing an appropriate ducted system you added a mini split? FFS.
If you need a “boost” add automatic dampers in your conduits to make independent zones
I was told that zoning central air with dampers doesn't end up working very well. Do you have experience to the contrary? I would need like 10-12 zones.
You design a custom home with a light well washing the double height wall with daylight and then you put an ugly AF mini-split head right at eye level as you come down the stairs. Obvious conclusion: the mini-split manufacturer sponsored the mechanical system video during Matt’s house build.
install a Voltage monitor you don't want to pay for that warranty repair.
Can you elaborate, please?
Can run them on solar for free AC/heat all year long
Mr. Cool mini-splits are the best! ❄🔥
I'm assuming you have one? Have you ever had to get it serviced? I have heard, not sure hence the question, that many HVAC people will not touch them
He spent how much money on that Ferrari of an erv (his words) and spent so much time talking about all of his amazing air filtration. But he still has a stand-alone unit for air filtration in each bedroom?
😂😂😂
or
😭😭😭
forced air return air grates are hideous
The whole installation on that wall is hideous. Why would you wash the wall with daylight from above and then put an ugly mini-split head right at eye level coming down the stairs and air return grilles on either side. I think he reinforced myth #1 rather than debunking it. The view at 7:00 is so bad; I would have been too embarrassed to even show that clip. And then how Steve can stand there with a straight face as an architect is beyond me. And then you cut to the bedroom where you’ve had to add one of those useless air recirculating units in each bedroom because your expensive ERV system is inadequate… I lost a lot of respect for you guys with this video.
Maybe give a little more background info next time because minis have been invented for heating and are more efficient in that mode than in cooling so northern climates can use them.
DNO - DO NOT OVERSIZE! Mitsu has a paper on that dated 10+ years. Those units are not great for dehumidification (90/10 SHR) and oversizing is bad. I hear so many contractors say that it’s ok because they ramp down to 20% ish of capacity but they don’t understand the tech behind all that. Manual J!
What's wrong with ramping down? If a one ton head is running at 50% speed, it would be the same as a half ton unit for dehumidification. What am I missing?
@ a lot but it’s late and I need to sleep. I’m sure a decent VRF tech will give you the answer
Having a mitsubishi mini split in east texas is no fun. No matter how much you clean the filters, the fan coil gets dirty and i have to take it apart every 6 months because of dust and mold 😒. Thats the reason im doing a traditional heat pump hvac system in my new house build.
Right?! I was all into mini splits until I watched a video on how to clean them. Huge pain and that's just for the wall mounted ones. The recessed ones are even harder to clean. Imagine doing all that for four different mini splits twice a year!
@christopherbenjamin9273 Seriously, a friend of mine has a house with 6 of the heads and he regrets it for sure 😬
The minisplit floor-based units look a lot better. Having those where you use them almost exclusively for heating is nice, too, as you are heating across the floor. I just think they look ugly when they're sitting on a wall. They could make them a lot nicer looking by making them black or stainless or something other than just off-white.
avoid LG brand like the plague.
This video is right is right on, mini splits are great for heating and cooling. However they are a maintenance nightmare so if you like mold blown around your house and $400 to $600 maintenance bills per year buy a mini splits, you'll love them! My experience was that any energy savings you have are blown on astronomical annual maintenance bills. If you have mini splits you will have poor indoor air quality mold mildew dust.
IQ-AIR!!! Dude If your going to do stand-alone filtration there’s nothing that beats “Swiss Made” I can’t believe you don’t know about IQ-Air, not crazy expensive and Hospitals use them. They can remove the smallest particles known to man. I have sleep apnea and I wear a blood O2 monitor to bed and my blood oxygen levels are 4-5 points higher when these are on. I’ve had air filters my whole life and nothing compares to these. Did you guys know we are all breathing microplastics? I just found that out. There’s so many things in our environment that are trying to kill us and we find out about more everyday. That’s why I bought the filter that can filter down to the smallest possible molecule. Or in the filter world they call that a micron and these go lower than 1 micron. That way only O2 can fit through the holes. It’s technically called air scrubbing or air washing when you get that low on the scale. Also IqAir last 2-4 years because there’s so much surface on thier filters. If you pulled one apart and laid all the filter area flat it’d be the size of a car versus the next best, Dyson which had way small filter contact surface area like 4x4 feet. Can’t believe that much can be fold into those tiny machines
I've owned a large HVAC company that does thousands of installs per year. Ductless are great for bonus rooms or garages, but traditional systems are better 99% of the time. Main reason are that ductless are a pain to service and in my experience have a much higher chance of failure (the pumps they use are often loud and annoying). Additionally, the techs cannot have the parts on them to easily fix while there like they can for regular split systems. In most cases splits systems are less money too. These ducted "mini-split" systems or the ones with multiple interior heads are very expensive, and do not work the way people think. You cannot heat and cool each room/zone simultaneously without upgrading to even more advanced systems that are extremely expensive. Simply not practical.
PS -- If you are needed ductless due to some reason that a regular split will not work, Id recommend you stick with main brands like Daikon and Mitsubishi that offer legit warranties, and go to a ceiling cassette that looks much cleaner and has the pump already built in.
One thing that isn’t a myth is how ugly that thing is.
Tbh yea they are hideous. But also, why not just put in a pizza box and duct a single room with it? Also makes sure everyone's happy with their own zone.
Edit: nvm he actually did this XD
Ducted mini split?🤨🤨... Ok at what point is it no longer a mini split and just a small central heating and air unit...
the ducted units have lower BTUs than most stand alone ducted systems, also this allows zoning, and you can add filtration to the incoming air side
You can run several ducted heads off one outdoor unit, so you can still get better zoning. You have the option to mix and match tonnages and form factors. I opted for all ceiling cassettes for simplicity and optimal zoning.
Agree, a mini split does the heat/cold transfer directly with the air in the room that they intend to heat/cool down.
When you add ducts and do the heat/cool down another place it’s just a normal ventilation, size doesn’t matter
Since you didn't mention it as a Myth... From observation of several TH-cam Videos.. Mini-splits are difficult to clean. Apparently, the mini-split manufacturers do not make them easy to disassemble for cleaning and have many plastic wearing parts (that wear or are easily damaged when disassembled, eg. metal screws into plastic). Additionally, cleaning is recommended 1-2 times per year. Are these thing really designed for a 20 year lifespan?