Thanks Adam, this is very thought provoking. Just a few points. The solar radiation of 1000W/sq m is for a surface perpendicular to the incident rays and we can expect something like this on a cloudless day in summer. In winter the sun is lower and thus takes a longer path through the atmosphere, so perhaps 2/3 of this at noon. On the ground it is spread out, half that power if the sub is 30 degrees above the horizon. Much better on the walls though. I think that mirrors may give a net reduction over the course of a day unless you have a sophisticated tracking system. Without the mirrors, visible and near IR radiation will be absorbed by the ground and wall surfaces. Heat from these surfaces will be transferred to the air passing across these surfaces when the fan is running. I had a HP installed a few weeks ago on the patio in the rear SE facing garden. I'd lifted some slabs and laid dark slate chippings. Using an IR thermometer I checked the temperature on a sunny say with ambient temperature of 26 C. Temperature on the grass was 27, the grey concrete slaps were 43 C, and the slate was 54 C. You have mentioned the first law of thermodynamics before, and clearly this heat must go somewhere. Some will be radiated as long wave IR, but much will transfer to the air by forced convection. Its a similar effect blowing on hot food transfers heat to the air. How much heat is gained with dark aggregate, or indeed with your mirrors is difficult to assess as there are so many variables such as ambient temperature, flow temp, internal or HW temp etc that are difficult to control. Even a whole season comparison might not be valid. One month or even one season is not the same as last yeats, or next. Just compare results from PV monitoring. I would like to see more work on this. Perhaps a brick shed with identical heat pumps on the north and south sides, heating identical loads such as uninsulated HW tanks. They could be programmed to run at identical scheduled times with performance 14:14 data collected from the HPs as well as sunshine data and temperature and wind sensors around the HP. Further trials would involve changing the wall and surrounding ground conditions to assess what solar gains can be achieved. I am not sure if this work has been done, but it needs to be and the results widely shared. I know my red brick wall, grey slabs and dark slate will have some solar gain but have no idea how much. If it totals 10 kWh per year, then if you need to prepare, go with whatever pleases you. If it is 500 kWh, then we need to know about it. It will not only inform designers, installers and customers, but also architects and developers. I am pretty sure it will be somewhere in between. All new builds with heat pump installations should aim to make the system as efficient as possible. A HP owner featured his installation recently. It is a newly built house with an unshaded South facing aspect. The bricks and gravel are both light in colour. I can't help thinking this was a missed opportunity.
A couple of thoughts… I had considered surrounding the heat pump with heat storing materials that would keep warmth more intense while the sun shines and longer after it’s gone since the pump extracts heat from the air surrounding it. I had also thought of a heat sink and duct device to have the heat pump cool a solar panel array by blowing cold air while extracting/using its heat.
@@HeatGeek also, when thinking about materials around the pump look into PCM “phase changing materials”. These might respond to weather more gradually and retain heat for much longer. These materials tend to maintain a set temperature around it (according to their composition).. might not be practical yet but you’ll geek out with the possibilities I am sure. There are companies making bricks, thermal batteries and home water heaters out of them. Really promising stuff ! I am learning a lot from the videos in this channel, please keep them coming!
While this is super interesting, you did change two variables. You moved the evaporator into the sun, and you also added the mirror. You really need to run without the mirrors for a period to see just how much impact putting the evaporator into the sun alone causes.
Just a random thought. The heat pump was standing on a black roof (black roofs get very hot) and it was standing in front of a white wall (white reflects heat and keeps cool). Does the colour of the surroundings affect the local ambiant temperature? What was the temperature on the ground in the shade? If you paint the wall black would that have a similar effect? So many questions... I'm looking forward to some relatively unscientific answers... Great work.
I have been considering fitting some black/dark grey composite decking boards or cladding to the wall behind my heat pump (which is south facing) to absorb the sun energy (when it’s out), so it would effectively preheat the air before being drawn in to the heat pump.
There is so much that could be done with HP design to boost efficiency. Top mounted evaporator always in the sun, greenhouse enclosure on top of that, heat recovery from kitchen extraction, flue heat, so much to be done!
@@HeatGeekexactly it’s on for 15 minutes a day and full of grease. It’s like economisers on combi-boilers, theory is great, they reduce your costs for heating hot water but they’ll never pay for themselves and the maintenance liability is too much.
I love this. Getting inventive. Something will work and be the next step forward. What about solar thermal in the loop, reduce the load on the heat pump?
The idea does have merit. James Biggar here on youtube did a very impressive solar pv/thermal hybrid system. He flanked a heat pump on either side with custom-fabricated solar pv panels that channel air behind them. In winter, this pre-warms the air going to the heat pump, and captures the solar energy as heat that the pv doesn't collect. In summer, it's isolated from the heat pump, and a blower blows the reverse direction to cool the pv modules with ambient air.
I feel like a large black heatsink or mass sat directly on the intake side of the heatpump (arranged so fins wouldn't obstruct the flow of air) would do wonders, particularly sunny days in spring and autumn when the air is cold but the sun is still bright.
Interesting experiment - when COP is quoted, the 400% efficiency is not really creating extra energy from the heat pump, but extracting energy from the atmosphere; in the case of an air source heat pump, the energy is almost all from the air (maybe a little from solar gain); Air is not a great medium for holding energy, so trying to warm the air around a heat pump will probably have little impact on the overall efficiency.... On the other hand, water is an excellent medium for storing energy, so if feasible, a solar thermal collector could be used to feed a large thermal store (1000 litre +) with daytime heat when the sun is switched on... then when needed, a water to water heat pump could then pump that 'warm' water around its inards (like a ground source heat pump) to boost the heat and feed the internal needs within the property. Not the most space efficient solution, but perhaps another experiment could be tried??!
Would be quite easy to integrate that into a ground source heat pump design, I suspect you are much better off just using the roof space for PV and running the heat pump off of that solar power, PV is so cheap now it makes hydronic systems just seem a liability.
@@edc1569 True point, and PV has the added benefit of allowing energy for a multitude of uses, but for maximum efficiency, solar thermal is a lot better than PV (per sq.m); the main point is for harvesting energy and smoothing demand for when it is required. If a relatively small amount of heat/hot water is needed then it would make more sense to store internally in a tank, but where space is available, large water tanks can be used even for seasonal energy storage over a longer period of time.
We can easily calculate the available sunlight energy falling on the unit and hence work out what the theoretical maximum gain could be, which in Dec/Jan/Feb will probably be very little, but could be useful in Jun/July/Aug
This is quite interesting. I am currently doing a new build apartment with a heat pump on a first floor balcony. The balcony has a relatively open metal balustrade with the back of the unit facing southwards. If what you are saying proves to be correct the heat pump for this apartment should be more efficient in this configuration.
Definitely check out the new low profile range from Urban Cooling, Chatham - ideal for apartments and conservation areas (no, I don't work for them 😂) Well worth a look @HeatGeek
Adam, I would propose you the following idea. You can repaint all the surrounding of the heatpump in black - the back wall and underneath it. In this way you will achieve an emmisivity factor of the wall of 0,99 and all the sun radiation will be absorbed and transferred to usable heat. In addition to this you can use mirrors to focus more sunlight to the black painted spot and this way achieve more heat. this idea is almost the same as yours but more easylly transformable to more locations and removing the obstacle that the condenser of the heatpump has na emmisivity factor of 0,4 - 0,5 and low perpendicular area subjected to sunlight due to it`s structure of alluminium fins.
Paint the cover black in sted of the white color. And exchange the mirror with a black background in sted. In winter time use exhaust air from the house (toilet, bath and so on) to exit to the heatpumt. Then the heat pump get air twmp og minus mixed with 20 degrees from inside.
Another test you could try: If you have a radon fan that pulls air from below your basement floor with a temp around 55F, exhaust that 55F air into the intake of the heat pump all winter long and my bet is the efficiency of the heat pump would do better when the outdoor temps are below freezing.
wondering what difference having black tubes behind perspex up the side of the building would make? they use this occasionally for adding heat to outdoor sheds. The idea is that the sun heats the tubes and air is forced up through due to warm air rising... this air could be fed behind the heatpump to add a couple of degrees to the air temperature maybe?
Have been talking to someone taking your training course , I offer this for feedback , they felt there was a lack of information provided , it was a case of you need this , now go and find out about it , surely the idea of training is to provide the answers and why they are the answers , obviously research is beneficial but it’s a balance .
You could just paint the wall black that it's near and if you wanted to redirect the light nearer the unit, you could just point the mirrors to reflect the sun on to the black wall
Something else to consider is the radiative cooling effect. In the human body we lose most heat due to radiation. This is why we wear clothes, or a knitted blanket or a sweater with lots of holes in it still keeps us warm. (it beaks up the radiation of heat off the body.) While everyone understands mirrors reflect light, certain materials reflect heat. And the sky is cool. So one could inadvertently cool the unit, (day or night) by reflecting heat off into space. Thermal cameras can be good at showing the difference in how materials reflect heat. At night, the mirrors might reflect the cold of the night sky onto the unit causing it to work harder. You might get better radiative cooling at night in the summer.
Wouldn't taking the (warm) air out of your loft make the most sense? Probably a good 10C above ambient even on a cool day and mostly non-directional (vs mirrors etc). Bolt an ASHP on the gable with a hole/duct to pull it out. Will also help ventilate the roof space at the same time, see a reduction in heat cycling/stress on the roof structure, reduce roof to habitable space heat transmission during summer, exhaust cool air at high level to guard against freezing of nearby paths. A win-win-win-win-win. Modern insulation at 270mm+ thick should mitigate the resultant increased deltaT between the habitable and roof space in winter. There is one (major issue): the Town and Country Planning Act 1990. Would be a good experiment though. PS. Probably scope for a H/W cylinder in the roof space the other side of the same gable. Win x6!
At times maybe but our loft in the colder weather is essentially the same as outside maybe a few degress. Most lofts are so well insulated these days esp those with heat pumps
In the winter at night it may make the situation worse, as effectively you will be surrounding the hat pump with sky at -30 if it is overcast or -200C rather than a building at 0C. So you will be losing extra heat by radiation rather than gaining it.
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You should use a heliostat mirror if you do longer term testing. That’s a tracking mirror that will keep reflecting on a certain spot as the sun moves actoss the sky
Interesting stuff. I would be interested to know about timer settings.... is running timed DHW first followed by heat more efficient than heat then DHW... my thinking is In option 1 that 'extra' flow temp can be used to kick start the heating by warming the rads and pipes, or in Option 2 is it better to have a pre heated flow before ramping up? Or does it make no difference or is it better to simply let the system heat the cylinder when it thinks is best? In my circumstances I have a time of use tariff, so use timers and cheap electric to heat DHW in afternoons when air is warmest to help boost efficiency, but does the order make any difference?
Interesting experiment. I think you would get better results from having the unit setting on black rooftop so it would use radiant heat from the surrounding area not just the area of the unit. Of corse this would be counter productive in summer
Her Adam. Can you do a video on hybrid heat pumps and boilers. How much could you reduce the heat pump power and improve the scop where you would be running the boiler or heating the water with the boiler. So when the outside temperature is low but not too low how much could you save ?
You've gone with mirrors, which is the ultimate in reflecting energy onto the evaporator. I wonder what the results would be using highly reflective white paint - paint some plywood boards and see what the results are. Do you have some volunteer heat pumps out there who would be interested in adding to the data sample?
I like the idea, but probably jusy easier to put up extra solar panels and let them eat the photons directly, then use the electricity generated to power the heat pump!
@@CCyoutube0in the UK solar panels are about £100 now, a mirror that can survive being outside all seasons and cleaned is going to be more expensive than a solar panel as it’s a specialist item.
What if you would add a soda pop can heater, that will collect the suns heat and disperse that onto the evaporator. Would like to see if that would work too.
I stuck my mini-split outdoor unit in a north facing corner for this very reason as I will be using it primarily for cooling and the temp difference between north and south on a boiling hot day can be around 10C out of the sun - sadly it won’t be ideal positioning in the months when I use it for heating…on the plus side it will be using free electrons from the sun to run in either case anyway 😊
I've been wondering recently why they don't combine heat pumps with a thermal collector on the roof, that pumps hot water down/around a small radiator in front of the evaporator, when it's it heating mode.... 🤔
You & everyone has a huge thermal heat sink which is your loft space as long as you haven't had a loft conversion. Could you not run some conduit from the loft space to the back of the heat pump have a vent the opposite end from where the conduit is have some one way flaps to create a draw that when the fan kicks in blows the hot air over the heat pump. Would be a cheap way to boost output?
woulda gone with a fresnel lens, no reflection. 15"x15" on ebay for 35£, you'd be able to vary the distance from the evaporator to adjust the focal length.
I haven't watched the entire Video yet, but I would have guessed, that the impact of the sun it mitigated or even nullified due to the large amount of air the unit pulls through the evaporator...
As an average, what is the difference in performance when heating a hot water cylinder in cold winter temperatures against the warmer summer temperatures ? Thank you
I wonder, perhaps painting the bit of patio in front of the heat pump a dark colour would mean that is radiating heat through the day that the fan would pull in?
Why do you not look at waste hot water recovery? You mentioned you ran the bath to run the tank dry, but most people have a shower - water going out, same volume in. That waste water has got valuable heat in it, no?
C'mon lads, you can't be struggling for content this bad. That mirror is going to do sweet bugger all! Solar assisted heat pumps have been around for a while. The French use the 50mm ventilation voids in the roof as a warm air source. So if you wanted to, but some larger soffits in the eves on the south side, and install the heat pump in the gable end wall of the attic - drawing air from the attic, with a makeup air event at the other end if the pressure difference is too large.
@@HeatGeek I'm not being that serious, either :). Yeah, vented solar thermal roof systems are a lot of faff for the benefits. I would send you a link, but it's become so uncommon it's hard to find. 10 years ago there was a buzz around them. I think the main problem was there were a lot of approaches to directly vent the heat into the building. If you have a cooling demand, then it becomes a terrible idea. Then there's the building regs, the unfamiliarity of the approach, all for modest gains - most people aren't willing to risk that.
Cool experiment. The better way would be catching the energy of the sun with a solar panel (either thermal or electric), and complement your heat pump with it. Way more effective ;) But nice test anyway.
You could just use a heat recovery unit or a mvhr system but that would require you to have well sealed home to justify and usually isn't worth the investment unless you suffer with damp or humdity
I guess if this works you could design a heat pump with a secondary movable evaporator that slides up above the unit. Then have a photometer/thermometer that lifts it up into the sun and then back down when not sunny helping with wind chill on cold non sunny days. This wouldn't take up much more room than a standard unit.
Cautionary tale: reminds me of an issue I had with my NIBE a couple of days over the summer. Quite warm sunny days with very little wind. One of the temperature sensors was measuring over 40degC air temperature [quite a bit above the actual air temperature]. This was apparently too hot for the ASHP to function to start a DHW cycle [NIBE alarm #272 "Temperature of BT28 above the value that permits operation"]. I rectified this by using a household fan to blow some air around the unit and cool the sensor down, and then when it measured
Nibe have pushed out a software update that runs the external fan for a few minutes before attempting a compressor start if BT28 exceeds 40C. You can also just cool the sensor locally if required. It is on the rear corner of the unit at the top in a black tube, clipped into the frame by the condenser.
Ah, interesting - that update sounds like just what is needed! I have the SMO 20 connected up to myUplink and I am just one software version behind, haven't gotten around to that update yet. Doesn't mention anything about this on the release notes, though :/ Or is this update for a different controller [or a firmware update for the ASHP itself, if that's a thing]?
@@stevedeveaux3502having re read the release notes, I can see it was added in v9542R2 on 17/03/22 however only for the F2120 unit. I had assumed it was an SMO20 update that covered all outdoor units. We’ve not had such high temperatures since I’ve updated so I’m unable to test this for now.
Do Vaillant allow mirrors in the R290 zone or are they still reflecting on that?.. ill see myself out and I’ll expect to be removed from the map in the morning 😂
My Mitsubishi unit sits behind a fence with the wall behind facing SSE and the micro climate often indicates a temperature of 8-10 degrees higher than the ambient temperature hence heating hot water in the late morning gets the best COP.. I have oft thought that siting a heat pump in a glass enclosure like a conservatory would boost the COP. Obviously you would need to vent the cold air but it would be a promising way of boosting efficiency in the North of Scotland.
I have 55F degree ground water under my basement all year long. Do you think if I pumped it out to my air to air heat pump coils either tubes pouring it on them or heating the frame or pooling thw water somehow below it to heat the coils in sub freeIng weather? That might be a neat experiment to test out!! I dont have hard water but would probably use a filter if i did something
Too late for that!! And no idea if it's enough to run the whole unit. I wish I could have an extra loop running into the sump pit water as it's a 5 zone fujitsu halcyon system with only 3 heads attached but all loops have to run the same way so it would only heat the water not pull heat from it. I'm trying to figure out if I can give some extra heat to the outside condenser in extreme cold to help it keep up with heating our home. I don't think I need it in the summer as it runs well enough and we do have solar to offset but it uses so much more electricity in the winter than in summer.
Am I missing something..... The air is constantly being sucked through the evaporator therefor no gain via mirrors as the fins are constantly heated by the moving air not the sun shine. The best way to get the most efficency is to fit a hydrogen boiler. The other way to get efficiecy is run it in the summer when demand for hot water is very low like your video shows
I think the relatively worm but humid air blowing on the evaporator would help, however not as much as you think, because the added humidity would cause ice buildup way faster
The point of a MVHR is to extract the heat from the outbound air and transfer it to the incoming air to warm it up. Therefore the outgoing air has already had the heat extracted from it. You could have a dedicated unit that has phase change material in it and push that heat out but I doubt you will create more efficiency than you would consume as you’d probably need to add mechanical assistance.
What would be interesting is if those HP had MPPTs on them and you could just plug directly solar panels on them. They are DC systems anyways. There are some mini split air conditioning units from China that can do that. Just plug in 2-3 panels and no need for bureaucracy to connect to the grid etc. Panels are dirt cheap now. Like $0.15 /Wp cheap. They would also "protect" the unit from weather somewhat if the panels are placed on top of it.
@@edc1569 Still those solar panels are dirt cheap. And this means in warmer climates the HP can be used for cooling using the energy from solar panels. And even in winter they will cover some of the electricity costs.
It's already black. Applying more paint will be likely to act as an insulator. These units have the back with the evaporator facing the wall. Most heat transfer into the evaporator is by forced convection, not radiation.
You don't achieve anything with that except you force the eev to open more because the mirror overheats the overheated steam, which is dangerous for the compressor. . Up to 2C outside temp, something like this is actually harmful for the heat pump
Maybe you are looking at this the wrong way around? if you could use a way of getting the cold water temp up from maybe 14C to 21C or hotter could reduce amount it has to do in first place?. I am installing a system than produces all my hot water for free, I have a 3.5kw solar installation which uses my simple electric hot water tank of 300L and a 2kw element in the summer it runs my pool pump and hot water and I hope in the winter just my hot water (i live in south west France so might get a bit more sun) I have self installed panels for about 2000€ and here should give me about 3500kwh per year
I'm all for testing and this experiments, but that click-bait title and click-bait thumbnail is not how you are going to honestly grow your channel, especially with the improper testing and non-existing results (which the title and thumbnail imply).
Aw mate you missed the opportunity to communicate some proper engineering principles in this one. Everyone's here in the comments trying to come up with ideas to warm the 'source' air when you're very obviously reflecting radiant heat directly onto the condenser itself. You could have told them the difference and why it's almost impossible to do it the other way...
Why not? A lot of knowledge gained comes from experimenting with things rather than just theorising them. Doing this doesn't take away from heat pumps being one of the best ways to heat your home.
Thanks Adam, this is very thought provoking. Just a few points. The solar radiation of 1000W/sq m is for a surface perpendicular to the incident rays and we can expect something like this on a cloudless day in summer. In winter the sun is lower and thus takes a longer path through the atmosphere, so perhaps 2/3 of this at noon. On the ground it is spread out, half that power if the sub is 30 degrees above the horizon. Much better on the walls though.
I think that mirrors may give a net reduction over the course of a day unless you have a sophisticated tracking system. Without the mirrors, visible and near IR radiation will be absorbed by the ground and wall surfaces. Heat from these surfaces will be transferred to the air passing across these surfaces when the fan is running.
I had a HP installed a few weeks ago on the patio in the rear SE facing garden. I'd lifted some slabs and laid dark slate chippings. Using an IR thermometer I checked the temperature on a sunny say with ambient temperature of 26 C. Temperature on the grass was 27, the grey concrete slaps were 43 C, and the slate was 54 C.
You have mentioned the first law of thermodynamics before, and clearly this heat must go somewhere. Some will be radiated as long wave IR, but much will transfer to the air by forced convection. Its a similar effect blowing on hot food transfers heat to the air.
How much heat is gained with dark aggregate, or indeed with your mirrors is difficult to assess as there are so many variables such as ambient temperature, flow temp, internal or HW temp etc that are difficult to control. Even a whole season comparison might not be valid. One month or even one season is not the same as last yeats, or next. Just compare results from PV monitoring.
I would like to see more work on this. Perhaps a brick shed with identical heat pumps on the north and south sides, heating identical loads such as uninsulated HW tanks. They could be programmed to run at identical scheduled times with performance 14:14 data collected from the HPs as well as sunshine data and temperature and wind sensors around the HP.
Further trials would involve changing the wall and surrounding ground conditions to assess what solar gains can be achieved.
I am not sure if this work has been done, but it needs to be and the results widely shared. I know my red brick wall, grey slabs and dark slate will have some solar gain but have no idea how much. If it totals 10 kWh per year, then if you need to prepare, go with whatever pleases you. If it is 500 kWh, then we need to know about it. It will not only inform designers, installers and customers, but also architects and developers. I am pretty sure it will be somewhere in between.
All new builds with heat pump installations should aim to make the system as efficient as possible. A HP owner featured his installation recently. It is a newly built house with an unshaded South facing aspect. The bricks and gravel are both light in colour. I can't help thinking this was a missed opportunity.
A couple of thoughts… I had considered surrounding the heat pump with heat storing materials that would keep warmth more intense while the sun shines and longer after it’s gone since the pump extracts heat from the air surrounding it.
I had also thought of a heat sink and duct device to have the heat pump cool a solar panel array by blowing cold air while extracting/using its heat.
Like this!!! Black brick led at the back!!
@@HeatGeek also, when thinking about materials around the pump look into PCM “phase changing materials”. These might respond to weather more gradually and retain heat for much longer. These materials tend to maintain a set temperature around it (according to their composition).. might not be practical yet but you’ll geek out with the possibilities I am sure. There are companies making bricks, thermal batteries and home water heaters out of them. Really promising stuff ! I am learning a lot from the videos in this channel, please keep them coming!
While this is super interesting, you did change two variables. You moved the evaporator into the sun, and you also added the mirror. You really need to run without the mirrors for a period to see just how much impact putting the evaporator into the sun alone causes.
Also reduced the restriction to airflow.
No. We changed 1 variable. We introduced more sunlight. If this works your suggestion is step 2.
@@HeatGeekpretty sure you moved the evaporator away from the wall too... 😂
Actually three... unless the pipe insulation removed was fully replaced, which it appears to only been partially done.
Airflow/wind speed across the unit should also be consistent for comparison, not just ambient temperature. Great content
Just a random thought. The heat pump was standing on a black roof (black roofs get very hot) and it was standing in front of a white wall (white reflects heat and keeps cool).
Does the colour of the surroundings affect the local ambiant temperature? What was the temperature on the ground in the shade? If you paint the wall black would that have a similar effect?
So many questions... I'm looking forward to some relatively unscientific answers... Great work.
I have been considering fitting some black/dark grey composite decking boards or cladding to the wall behind my heat pump (which is south facing) to absorb the sun energy (when it’s out), so it would effectively preheat the air before being drawn in to the heat pump.
Wouldnt that just help for a minute when it boots up? after that it's the same as before.
There is so much that could be done with HP design to boost efficiency. Top mounted evaporator always in the sun, greenhouse enclosure on top of that, heat recovery from kitchen extraction, flue heat, so much to be done!
Not a great idea to have a top facing evap - snow?
@@normanboyes4983 greenhouse/perspex cover with servo operated louvres 🤓
You know there’s a reason we don’t do this, it’s not worth it.
Tip facing Evap would fill with leaves and crap. Extractor energy is below peanuts I think???
@@HeatGeekexactly it’s on for 15 minutes a day and full of grease. It’s like economisers on combi-boilers, theory is great, they reduce your costs for heating hot water but they’ll never pay for themselves and the maintenance liability is too much.
I love this. Getting inventive. Something will work and be the next step forward. What about solar thermal in the loop, reduce the load on the heat pump?
@@GavinWilkinson NIBE do this solution!
The idea does have merit. James Biggar here on youtube did a very impressive solar pv/thermal hybrid system. He flanked a heat pump on either side with custom-fabricated solar pv panels that channel air behind them. In winter, this pre-warms the air going to the heat pump, and captures the solar energy as heat that the pv doesn't collect. In summer, it's isolated from the heat pump, and a blower blows the reverse direction to cool the pv modules with ambient air.
I feel like a large black heatsink or mass sat directly on the intake side of the heatpump (arranged so fins wouldn't obstruct the flow of air) would do wonders, particularly sunny days in spring and autumn when the air is cold but the sun is still bright.
Interesting experiment - when COP is quoted, the 400% efficiency is not really creating extra energy from the heat pump, but extracting energy from the atmosphere; in the case of an air source heat pump, the energy is almost all from the air (maybe a little from solar gain); Air is not a great medium for holding energy, so trying to warm the air around a heat pump will probably have little impact on the overall efficiency.... On the other hand, water is an excellent medium for storing energy, so if feasible, a solar thermal collector could be used to feed a large thermal store (1000 litre +) with daytime heat when the sun is switched on... then when needed, a water to water heat pump could then pump that 'warm' water around its inards (like a ground source heat pump) to boost the heat and feed the internal needs within the property.
Not the most space efficient solution, but perhaps another experiment could be tried??!
Would be quite easy to integrate that into a ground source heat pump design, I suspect you are much better off just using the roof space for PV and running the heat pump off of that solar power, PV is so cheap now it makes hydronic systems just seem a liability.
@@edc1569 True point, and PV has the added benefit of allowing energy for a multitude of uses, but for maximum efficiency, solar thermal is a lot better than PV (per sq.m); the main point is for harvesting energy and smoothing demand for when it is required. If a relatively small amount of heat/hot water is needed then it would make more sense to store internally in a tank, but where space is available, large water tanks can be used even for seasonal energy storage over a longer period of time.
How about painting the wall black around the the heat pump?
I was thinking the same, this could potentially provide extra radiated heat to the unit after the sun goes down. Hard to test, so many variables.
Interesting, thank you. Where did you source the mirrored panels, please?
We can easily calculate the available sunlight energy falling on the unit and hence work out what the theoretical maximum gain could be, which in Dec/Jan/Feb will probably be very little, but could be useful in Jun/July/Aug
I’m a bit surprised hearing you talk about instantaneous scop. Instantaneous cop would be more likely?
The only thing i heard was the heatpump running from 8.36 lol, wasnt very quiet
This is quite interesting. I am currently doing a new build apartment with a heat pump on a first floor balcony. The balcony has a relatively open metal balustrade with the back of the unit facing southwards. If what you are saying proves to be correct the heat pump for this apartment should be more efficient in this configuration.
Definitely check out the new low profile range from Urban Cooling, Chatham - ideal for apartments and conservation areas (no, I don't work for them 😂) Well worth a look @HeatGeek
Adam, I would propose you the following idea. You can repaint all the surrounding of the heatpump in black - the back wall and underneath it. In this way you will achieve an emmisivity factor of the wall of 0,99 and all the sun radiation will be absorbed and transferred to usable heat. In addition to this you can use mirrors to focus more sunlight to the black painted spot and this way achieve more heat. this idea is almost the same as yours but more easylly transformable to more locations and removing the obstacle that the condenser of the heatpump has na emmisivity factor of 0,4 - 0,5 and low perpendicular area subjected to sunlight due to it`s structure of alluminium fins.
Paint the cover black in sted of the white color. And exchange the mirror with a black background in sted.
In winter time use exhaust air from the house (toilet, bath and so on) to exit to the heatpumt. Then the heat pump get air twmp og minus mixed with 20 degrees from inside.
Another test you could try: If you have a radon fan that pulls air from below your basement floor with a temp around 55F, exhaust that 55F air into the intake of the heat pump all winter long and my bet is the efficiency of the heat pump would do better when the outdoor temps are below freezing.
What is 55F?
@@edc1569 12.7C
A 10kW heat pump is going to be pumping like 300L/s if air through it, I suspect your radon extraction is less than a tenth of 1% of that.
@@edc1569 good point, perhaps it won't make any difference. But it would be a fun test to watch.
Solar assisted heat pumps! Always wanted to try one, use a water to water with big solar/air collector. Could be fun.
wondering what difference having black tubes behind perspex up the side of the building would make? they use this occasionally for adding heat to outdoor sheds. The idea is that the sun heats the tubes and air is forced up through due to warm air rising... this air could be fed behind the heatpump to add a couple of degrees to the air temperature maybe?
Have been talking to someone taking your training course , I offer this for feedback , they felt there was a lack of information provided , it was a case of you need this , now go and find out about it , surely the idea of training is to provide the answers and why they are the answers , obviously research is beneficial but it’s a balance .
You could just paint the wall black that it's near and if you wanted to redirect the light nearer the unit, you could just point the mirrors to reflect the sun on to the black wall
Something else to consider is the radiative cooling effect. In the human body we lose most heat due to radiation. This is why we wear clothes, or a knitted blanket or a sweater with lots of holes in it still keeps us warm. (it beaks up the radiation of heat off the body.) While everyone understands mirrors reflect light, certain materials reflect heat. And the sky is cool. So one could inadvertently cool the unit, (day or night) by reflecting heat off into space. Thermal cameras can be good at showing the difference in how materials reflect heat. At night, the mirrors might reflect the cold of the night sky onto the unit causing it to work harder. You might get better radiative cooling at night in the summer.
Wouldn't taking the (warm) air out of your loft make the most sense? Probably a good 10C above ambient even on a cool day and mostly non-directional (vs mirrors etc). Bolt an ASHP on the gable with a hole/duct to pull it out. Will also help ventilate the roof space at the same time, see a reduction in heat cycling/stress on the roof structure, reduce roof to habitable space heat transmission during summer, exhaust cool air at high level to guard against freezing of nearby paths. A win-win-win-win-win. Modern insulation at 270mm+ thick should mitigate the resultant increased deltaT between the habitable and roof space in winter. There is one (major issue): the Town and Country Planning Act 1990. Would be a good experiment though. PS. Probably scope for a H/W cylinder in the roof space the other side of the same gable. Win x6!
At times maybe but our loft in the colder weather is essentially the same as outside maybe a few degress. Most lofts are so well insulated these days esp those with heat pumps
In the winter at night it may make the situation worse, as effectively you will be surrounding the hat pump with sky at -30 if it is overcast or -200C rather than a building at 0C. So you will be losing extra heat by radiation rather than gaining it.
You should use a heliostat mirror if you do longer term testing. That’s a tracking mirror that will keep reflecting on a certain spot as the sun moves actoss the sky
Love it
You could also automate it to point away to a safe spot (solar panels?) if the evaporator is overheating, or heat pump doesn't need to generate heat.
what about an IR lamp running of solar ?
How about a little greenhouse over the back of the heat pump?
Pulls too much air through it to matter. Or it would have to be freaking massive
Interesting stuff. I would be interested to know about timer settings.... is running timed DHW first followed by heat more efficient than heat then DHW... my thinking is In option 1 that 'extra' flow temp can be used to kick start the heating by warming the rads and pipes, or in Option 2 is it better to have a pre heated flow before ramping up? Or does it make no difference or is it better to simply let the system heat the cylinder when it thinks is best? In my circumstances I have a time of use tariff, so use timers and cheap electric to heat DHW in afternoons when air is warmest to help boost efficiency, but does the order make any difference?
Interesting experiment.
I think you would get better results from having the unit setting on black rooftop so it would use radiant heat from the surrounding area not just the area of the unit. Of corse this would be counter productive in summer
Her Adam. Can you do a video on hybrid heat pumps and boilers. How much could you reduce the heat pump power and improve the scop where you would be running the boiler or heating the water with the boiler. So when the outside temperature is low but not too low how much could you save ?
What app are you using for the Scop readings Adam? Where can I get it?
You've gone with mirrors, which is the ultimate in reflecting energy onto the evaporator. I wonder what the results would be using highly reflective white paint - paint some plywood boards and see what the results are. Do you have some volunteer heat pumps out there who would be interested in adding to the data sample?
I like the idea, but probably jusy easier to put up extra solar panels and let them eat the photons directly, then use the electricity generated to power the heat pump!
Why would that be instead rather than as well?
A mirror costs £50, a solar panel is more like £500 even if you add it yourself
Think a solar panel is only about €150
@@CCyoutube0in the UK solar panels are about £100 now, a mirror that can survive being outside all seasons and cleaned is going to be more expensive than a solar panel as it’s a specialist item.
@@HeatGeek
because you have not proved anything at all. maybe, something in it, it might, doesn't cut it.
What if you would add a soda pop can heater, that will collect the suns heat and disperse that onto the evaporator. Would like to see if that would work too.
I stuck my mini-split outdoor unit in a north facing corner for this very reason as I will be using it primarily for cooling and the temp difference between north and south on a boiling hot day can be around 10C out of the sun - sadly it won’t be ideal positioning in the months when I use it for heating…on the plus side it will be using free electrons from the sun to run in either case anyway 😊
I've been wondering recently why they don't combine heat pumps with a thermal collector on the roof, that pumps hot water down/around a small radiator in front of the evaporator, when it's it heating mode.... 🤔
You & everyone has a huge thermal heat sink which is your loft space as long as you haven't had a loft conversion. Could you not run some conduit from the loft space to the back of the heat pump have a vent the opposite end from where the conduit is have some one way flaps to create a draw that when the fan kicks in blows the hot air over the heat pump. Would be a cheap way to boost output?
just do “earth tubes” to warm the air intake… it would help for cooling in reverse, too.
I been told that Bosch is releasing a roof mounted heat pump that resembles a solar panel which I assume takes advantage of radiant heat.
woulda gone with a fresnel lens, no reflection. 15"x15" on ebay for 35£, you'd be able to vary the distance from the evaporator to adjust the focal length.
Wouldn’t an air source heat pump work better if it was fed by pipes coming from underground with a good run to moderate their heat?
I haven't watched the entire Video yet, but I would have guessed, that the impact of the sun it mitigated or even nullified due to the large amount of air the unit pulls through the evaporator...
Radiant passes through air so has no effect
Why not integrate a solar thermal unit on a south facing roof with the return flow to your heat pump?
would painting the back of the wall black help?
As an average, what is the difference in performance when heating a hot water cylinder in cold winter temperatures against the warmer summer temperatures ? Thank you
I wonder, perhaps painting the bit of patio in front of the heat pump a dark colour would mean that is radiating heat through the day that the fan would pull in?
How about painting the house wall in a dark color?
or build a black airflow tunnel / greenhouse tunnel
Bad idea, at night your house will radiate more heat. Black absorbs and radiates heat.
Why do you not look at waste hot water recovery? You mentioned you ran the bath to run the tank dry, but most people have a shower - water going out, same volume in. That waste water has got valuable heat in it, no?
C'mon lads, you can't be struggling for content this bad. That mirror is going to do sweet bugger all!
Solar assisted heat pumps have been around for a while. The French use the 50mm ventilation voids in the roof as a warm air source. So if you wanted to, but some larger soffits in the eves on the south side, and install the heat pump in the gable end wall of the attic - drawing air from the attic, with a makeup air event at the other end if the pressure difference is too large.
This is just a bit of fun frank. Not sure about the French idea as it will increase the properties heat loss???
@@HeatGeek I'm not being that serious, either :).
Yeah, vented solar thermal roof systems are a lot of faff for the benefits. I would send you a link, but it's become so uncommon it's hard to find. 10 years ago there was a buzz around them.
I think the main problem was there were a lot of approaches to directly vent the heat into the building. If you have a cooling demand, then it becomes a terrible idea.
Then there's the building regs, the unfamiliarity of the approach, all for modest gains - most people aren't willing to risk that.
Cold winds in winter will need more defrosts.
Cool experiment. The better way would be catching the energy of the sun with a solar panel (either thermal or electric), and complement your heat pump with it. Way more effective ;) But nice test anyway.
So puting small fire 🔥 at back will help 🤣🤣
I was wondering if you could take the stale warm air out of the house and put it behind the heat pump in the winter
This might be scuppered by additional defrost cycles needed to deal with the extra moisture that will be present in that airstream.
I was planning to use the air in my attic during summer for a ashp water tank. And in winter switch the inlet to outside air.
That called an exhaust air heat pump, and a company called Nibe makes them :)
You could just use a heat recovery unit or a mvhr system but that would require you to have well sealed home to justify and usually isn't worth the investment unless you suffer with damp or humdity
Is this not the theory behind thermodynamic solar panels? Maybe there could be a combined ASHP with thermodynamic solar?
I have an issue with insects going in the electronics and shirt circuit. What can U do? Waranty replaceds ones but I doubt they will again
I guess if this works you could design a heat pump with a secondary movable evaporator that slides up above the unit. Then have a photometer/thermometer that lifts it up into the sun and then back down when not sunny helping with wind chill on cold non sunny days.
This wouldn't take up much more room than a standard unit.
Cautionary tale: reminds me of an issue I had with my NIBE a couple of days over the summer. Quite warm sunny days with very little wind. One of the temperature sensors was measuring over 40degC air temperature [quite a bit above the actual air temperature]. This was apparently too hot for the ASHP to function to start a DHW cycle [NIBE alarm #272 "Temperature of BT28 above the value that permits operation"]. I rectified this by using a household fan to blow some air around the unit and cool the sensor down, and then when it measured
Those NIBE units really are a bit bonkers.
Nibe have pushed out a software update that runs the external fan for a few minutes before attempting a compressor start if BT28 exceeds 40C. You can also just cool the sensor locally if required. It is on the rear corner of the unit at the top in a black tube, clipped into the frame by the condenser.
Ah, interesting - that update sounds like just what is needed! I have the SMO 20 connected up to myUplink and I am just one software version behind, haven't gotten around to that update yet. Doesn't mention anything about this on the release notes, though :/ Or is this update for a different controller [or a firmware update for the ASHP itself, if that's a thing]?
@@stevedeveaux3502having re read the release notes, I can see it was added in v9542R2 on 17/03/22 however only for the F2120 unit. I had assumed it was an SMO20 update that covered all outdoor units. We’ve not had such high temperatures since I’ve updated so I’m unable to test this for now.
@@LukeHopper-ms4tt Fair enough, thanks for checking 🙂
perforated steel plate against the wall with air gap behind?
Do Vaillant allow mirrors in the R290 zone or are they still reflecting on that?.. ill see myself out and I’ll expect to be removed from the map in the morning 😂
Hahaha 👍👍
put it on a black sand fundament ... and a solarheater to heat up the sandfundament ...
My Mitsubishi unit sits behind a fence with the wall behind facing SSE and the micro climate often indicates a temperature of 8-10 degrees higher than the ambient temperature hence heating hot water in the late morning gets the best COP.. I have oft thought that siting a heat pump in a glass enclosure like a conservatory would boost the COP. Obviously you would need to vent the cold air but it would be a promising way of boosting efficiency in the North of Scotland.
I have built a small greenhouse structure over the back of mine to cover the evaporator
If I will ever install an ashp I think I will also have black pavement around it. I imagine it will help a bit, if not, the yard is paved anyway.
I have built a small greenhouse structure over the top of my evaporator. Works.
How would the air circulate to replenish energy??
Any restriction to airflow is going to work against you, have to remember these devices are sucking 3-12 kilowatts of heat out of the atmosphere.
I have 55F degree ground water under my basement all year long. Do you think if I pumped it out to my air to air heat pump coils either tubes pouring it on them or heating the frame or pooling thw water somehow below it to heat the coils in sub freeIng weather? That might be a neat experiment to test out!! I dont have hard water but would probably use a filter if i did something
get a water to water heatpump
Too late for that!! And no idea if it's enough to run the whole unit. I wish I could have an extra loop running into the sump pit water as it's a 5 zone fujitsu halcyon system with only 3 heads attached but all loops have to run the same way so it would only heat the water not pull heat from it. I'm trying to figure out if I can give some extra heat to the outside condenser in extreme cold to help it keep up with heating our home. I don't think I need it in the summer as it runs well enough and we do have solar to offset but it uses so much more electricity in the winter than in summer.
Hi, I am thinking of installing a heat pump and would like to be in touch with you. Could you please let me know how you would be of my help? Thanks
you are wasting your time.
Please put mirror on floor and test back in old place and compare on a day at 18 oc no rain but like the thinking is free sun
I have solar, the time I need it the most ie December and January, it's useless. I think this would work out the same.
Am I missing something..... The air is constantly being sucked through the evaporator therefor no gain via mirrors as the fins are constantly heated by the moving air not the sun shine. The best way to get the most efficency is to fit a hydrogen boiler. The other way to get efficiecy is run it in the summer when demand for hot water is very low like your video shows
What about painting the fins in a thin layer of black 2.0?
the paint acts as a insulator,,
Surely a thin layer wouldn't make much difference?
@@robandrews9826 but it really does,, the energy has to go from a fast energy mover cross to a paint and back out to the air.
As above!
Interesting to see how a the heat pump would perform with exhaust from MHRV systems along the back
I think the relatively worm but humid air blowing on the evaporator would help, however not as much as you think, because the added humidity would cause ice buildup way faster
The point of a MVHR is to extract the heat from the outbound air and transfer it to the incoming air to warm it up. Therefore the outgoing air has already had the heat extracted from it.
You could have a dedicated unit that has phase change material in it and push that heat out but I doubt you will create more efficiency than you would consume as you’d probably need to add mechanical assistance.
Yey,green house with automatic roof opening
americans style AC-s have 360 degree evaporators (those cube looking units). So there should be no problem sun shining on them.
What would be interesting is if those HP had MPPTs on them and you could just plug directly solar panels on them. They are DC systems anyways. There are some mini split air conditioning units from China that can do that. Just plug in 2-3 panels and no need for bureaucracy to connect to the grid etc. Panels are dirt cheap now. Like $0.15 /Wp cheap. They would also "protect" the unit from weather somewhat if the panels are placed on top of it.
But when the heat pump isn’t running which is most of the time in summer you can do nothing with that electricity
@@edc1569 Still those solar panels are dirt cheap. And this means in warmer climates the HP can be used for cooling using the energy from solar panels. And even in winter they will cover some of the electricity costs.
Do you really get any sunshine in GB 😂😂😂😂
You need to watch this video! "The Mummy - Treasure Lighting Trick".
Next experiment, the blackest black paint applied to the evaporator...
It's already black. Applying more paint will be likely to act as an insulator. These units have the back with the evaporator facing the wall. Most heat transfer into the evaporator is by forced convection, not radiation.
You don't achieve anything with that except you force the eev to open more because the mirror overheats the overheated steam, which is dangerous for the compressor. . Up to 2C outside temp, something like this is actually harmful for the heat pump
they should get paint them all black
Wouldn’t it be easier to just swivel the heat pump to follow the sun? ;-)
Maybe you are looking at this the wrong way around? if you could use a way of getting the cold water temp up from maybe 14C to 21C or hotter could reduce amount it has to do in first place?.
I am installing a system than produces all my hot water for free, I have a 3.5kw solar installation which uses my simple electric hot water tank of 300L and a 2kw element in the summer it runs my pool pump and hot water and I hope in the winter just my hot water (i live in south west France so might get a bit more sun) I have self installed panels for about 2000€ and here should give me about 3500kwh per year
Pop it right next to the flue on the neighbours gas boiler, free heat.
Air holds little heat. Radiant has 1000w/m2!!
Careful with your ideas and experimenting on saving energy, you will go missing one day 😂
Pointless. If there is sun hitting the mirror, it would warm the wall and radiate to the heat pump anyway.
Scop is not cop!
White board would have been better? Thought mirrors albedo wasn't great.
I'm all for testing and this experiments, but that click-bait title and click-bait thumbnail is not how you are going to honestly grow your channel, especially with the improper testing and non-existing results (which the title and thumbnail imply).
Aw mate you missed the opportunity to communicate some proper engineering principles in this one. Everyone's here in the comments trying to come up with ideas to warm the 'source' air when you're very obviously reflecting radiant heat directly onto the condenser itself. You could have told them the difference and why it's almost impossible to do it the other way...
@@beetooexwatch the very beginning but again about moving the heat pump to the south side not really doing much.
oh... erm yeah your right 😂😂😂😂. The beginning of the video was a long time ago 😂😂😂
if heat pumps are the bees knees as you constantly tell us why are you doing this?
Why not? A lot of knowledge gained comes from experimenting with things rather than just theorising them. Doing this doesn't take away from heat pumps being one of the best ways to heat your home.
Wouldn't it just be a lot easier if we all just moved to Spain..