Basic Heating Control Understanding Help

[JamesPa]

12 minutes ago, Nickfromwales said:

34 minutes ago, JamesPa said:

if only to power defrost

This is a huge bone of contention.

 

12 minutes ago, Nickfromwales said:

34 minutes ago, JamesPa said:

if only to power defrost

This is a huge bone of contention.

 

If an ASHP has been spec'd to go into a dwelling that sympathises with such a unit, then freezing should be deleted? If it's Baltic outside and humid, ergo defrosting is prevalent, then the owner should be heating the DHW by the immersion(s) for that period of the year. The maths defo work out, as I've stated recently, just with the huge labouring of the HP being eradicated, plus the extension to the longevity of the HP / ancillary equipment. 

 

Sorry can you explain.

 

I thought that ashps get frost on them when it's around 4 outside and thus humid, because water from the air condenses on them, and that needs to be defrosted from time to time.  However dhw is heated the space heating is still needed.  Did I miss something?

Edited May 28, 2023 by JamesPa

[Nickfromwales]

8 minutes ago, JamesPa said:

Sorry can you explain.

 

I thought that ashps get frost on them when it's around 4 outside and thus humid, because water from the air condenses on them, and that needs to be defrosted from time to time.  Did I miss something?

It (requirement for defrosting cycle(s)) becomes prevalent when the ASHP is being asked to do things it doesn't like doing, and even more so when it's 'least best' to do so. The ASHP's I've fitted recently should literally almost never freeze. Retro-fit units into 1930's refurbishments will likely be defrosting a LOT, ergo I would never install an ASHP to such a property, (but where others would of course).

Low flow temps and strategizing when (and how) to heat DHW will all add to the SCoP and longevity of the equipment.

[Shaun McD]

3 hours ago, Nickfromwales said:

Nope. The post refers to shoulder months where the heating may not be needed during the day, but instead where solar gain becomes problematic for E > S sunshine in the morning, with the S > W and N rooms then waiting to get the heat and balance out the slab / room temps.

 

If the house calls for heat the HP will be fired by the heating controls, as will the manifold pump(s). With my preferred technique of running the manifold(s) pump(s) during sunlight hours the problem of each far side of the dwelling behaving differently, heat wise, is reduced significantly.

 

Ok so during shoulder months and I assume summer, run the pump during sunlight hours to help circulate the solar gain? 

 

3 hours ago, Nickfromwales said:

This is a huge bone of contention.

 

If an ASHP has been spec'd to go into a dwelling that sympathises with such a unit, then freezing should be deleted? If it's Baltic outside and humid, ergo defrosting is prevalent, then the owner should be heating the DHW by the immersion(s) for that period of the year. The maths defo work out, as I've stated recently, just with the huge labouring of the HP being eradicated, plus the extension to the longevity of the HP / ancillary equipment. 

If you have solar PV then you will be banking electricity tokens all summer to 'spend' on this pursuit, but at the time where this will be most problematic your CoP will be 2:1 if you're lucky, and much much worse if defrosting is repeatedly required and added to the maths. 

In the arse of winter I recommend that you heat DHW via a cheap rate electricity period via the cylinder immersion and only do the daytime heavy lifting at most eg maintaining the absolute lowest set point of say 50^oC.

 

I have been oversizing UVC's for years now, for exactly this reason. Bulk heavy lifting when the CoP has the advantage, and boosting up the temps (heat energy capacity) via the immersion to stay away from having to do this whilst low temp heat is being produced. The oversize also helps massively during summer where extra DHW can be stuffed into the same device (by "overheating" the UVC with 'free' energy).

 

This is very interesting and first time I heard this perspective. If I'm right then basic principle is that the risk of defrosting is much greater when the ashp is working in dhw and much less risk when doing central heating temps regardless of the load? So to help this one should try avoid having the ashp heat the dhw? Is that the general idea?

An example of the setup, say for Nov - Feb, reduce the ashp set point for dhw way down, and set a timer switch to bring on the immersion during night rate electricity to top up the tank to a modest set point of say 50c, and have pv add input whenever it can? Sound about right?

What sort of oversizing of uvc would you recommend? 

 

[ProDave]

18 hours ago, Shaun McD said:

Thanks @ProDave, why always a 2 port valve for each manifold and DHW? (ignoring solar gain redistribution). Would the one for DHW not be surplus to the valve controlling heat V DHW?

I have a dislike of 3 port valves but that dilike is 3 port mid position valves.

 

You can use a 3 port 2 POSITION valve to switch from DHW to UFH but that does not help you if you want two manifolds operating independantly or a mix f UFH and radiators where you will be better off then with three 2 port valves.

[SteamyTea]

16 hours ago, Shaun McD said:

losses will be pretty close to each other no

No.

 

You can calculate, pretty accurately, how warm a wall will get from sunlight by using PVGIS.

A wall is just like anything else left in the sun, it gets warmer, this reduces heat losses, or may actually increase room temperature.  It all depends on the make up of the wall, the exposed area and orientation, hence my NW and SW corner example.

There is also cases where you want rooms at different temperatures. A kitchen, used solely as a kitchen, probably needs a lower base temperature, than a living room, which may, in turn be higher than a bedroom.  Bathrooms probably have the highest temperature due to usage (lots of 40°C water, and the need to be kept dry after use.  Some of that heat, heat is the old term for energy, will travel though the walls into the adjoining area i.e. a bedroom or landing.

Changing the spacing of the UFH pipework for the same delivery temperature and flow from the ASHP/Boiler allows for different room temperatures and losses/gains.  This is why a room by room heat lose calculation is done, you can take into account the usage and the seasonal variations.

As an example, image that you have one loop that does the living room and downstairs cloakroom.

Water enters the pipe at say 35°C and exits at 30°C.  The cloakroom may only have 3m² of exposed wall, the other 3 are inside the house.  The living room may have 3 exposed walls, with only one within the house, so 50m² exposed to the outside.

Depending on which way the flow goes, the cloakroom may be getting water entering the loop at either 35° or 30°C, so may be either too hot or too cold if the pipe spacing is the same as the living room.

The problems start when designers just put in standard UFH pipework spacing and control it all by having multiple loops, each with their own thermostat and flow controller.  This is simpler to design, but harder to installer and a pig to control effectively.

 

You may well find that a fixed spacing will work well enough, but without knowing the  details, one cannot be certain.

So do those calculations, they are easy enough, just tedious.  It is what spreadsheets are for.

[Shaun McD]

56 minutes ago, SteamyTea said:

No.

 

You can calculate, pretty accurately, how warm a wall will get from sunlight by using PVGIS.

A wall is just like anything else left in the sun, it gets warmer, this reduces heat losses, or may actually increase room temperature.  It all depends on the make up of the wall, the exposed area and orientation, hence my NW and SW corner example.

There is also cases where you want rooms at different temperatures. A kitchen, used solely ass a kitchen, probably needs a lower base temperature, than a living room, which may, in turn be higher than a bedroom.  Bathrooms probably have the highest temperature due to usage (lots of 40°C water, and the need to be kept dry after use.  Some o that heat, heat is the old term for energy, will travel though the walls into the adjoining area i.e. a bedroom or landing.

Changing the spacing of the UFH pipework allows, for the same delivery temperature and flow from the ASHP/Boiler allows for different room temperatures and looses/gains.  This is why a room by room heat lose calculation is done, you can take into account the usage and the seasonal variations.

As an example, image that you have one loop that does the living room and downstairs cloakroom.

Water enters the pipe at say 35°C and exits at 30°C.  The cloakroom may only have 3m² of exposed wall, the other 3 are inside the house.  The living room may have 3 exposed walls, with only one within the house, so 50m² exposed to the outside.

Depending on which way the flow goes, the cloakroom may be getting water entering the loop at either 35° or 30°C, so may be either too hot or too cold if the pipe spacing is the same as the living room.

The problems start when designers just put in standard UFH pipework spacing and control it all by having multiple loops, each with their own thermostat and flow controller.  This is simpler to design, but harder to installer and a pig to control effectively.

 

You may well find that a fixed spacing will work well enough, but without knowing the  details, one cannot be certain.

So do those calculations, they are easy enough, just tedious.  It is what spreadsheets are for.

 

Thank you very much @SteamyTea that all makes sense now! Will try do some calculations and see where that leads but open to the idea of using different spacings now! I assume, if rooms do not share loops, a portion of this can be achieved by adjusting flow rate for each loop? From what I have seen though, the controls on this are not exactly fine, so I guess you wouldnt want to be relying on this as your only way to control it, thus the need for different spacings?

[JamesPa]

13 hours ago, Nickfromwales said:

It (requirement for defrosting cycle(s)) becomes prevalent when the ASHP is being asked to do things it doesn't like doing, and even more so when it's 'least best' to do so. The ASHP's I've fitted recently should literally almost never freeze. Retro-fit units into 1930's refurbishments will likely be defrosting a LOT, ergo I would never install an ASHP to such a property, (but where others would of course).

Low flow temps and strategizing when (and how) to heat DHW will all add to the SCoP and longevity of the equipment.

This is interesting, but Im still confused.  Cold and humid occurs during the season when space heating is needed (here in the South East of England its frankly cold and humid for much of the heating season, sadly, personally Id prefer it were colder and drier).

 

So although I agree that the time at which you heat DHW is adjustable, space heating is less so.  Unless you are suggesting offsetting the times of the space heating to avoid the cold/wet periods of the day.  I can see you could do this on some days but not every day.  Can you clarify your strategy to avoid defrost.  Is it basically oversize for the heating load and then run DHW when its not cold and wet?

 

Sadly, for the planet, avoiding 1930 refurbishments isn't an option.  Older properties are the majority of our housing stock!

Edited May 29, 2023 by JamesPa

[Nickfromwales]

1 hour ago, SteamyTea said:

The problems start when designers just put in standard UFH pipework spacing

The exact reason that on my current project (a fully certified Passivhaus) I am designing this issue out; manipulation of where flow goes first, selecting which pipes get insulated before reaching their target 'zones' and also by selecting different o/c's in different spaces according to discipline. One thermostat planned per floor but with a very tight hysteresis so the second there is fluctuation (up or down) the systems can respond quickly (as quickly as a PH can) and mitigate against over / under shoot. Solar gain over shoot is the offender that my efforts will be largely focussed on, heating is a doddle to deal with.  

[JohnMo]

2 hours ago, SteamyTea said:

No.

 

You can calculate, pretty accurately, how warm a wall will get from sunlight by using PVGIS.

A wall is just like anything else left in the sun, it gets warmer, this reduces heat losses, or may actually increase room temperature.  It all depends on the make up of the wall, the exposed area and orientation, hence my NW and SW corner example.

There is also cases where you want rooms at different temperatures. A kitchen, used solely as a kitchen, probably needs a lower base temperature, than a living room, which may, in turn be higher than a bedroom.  Bathrooms probably have the highest temperature due to usage (lots of 40°C water, and the need to be kept dry after use.  Some of that heat, heat is the old term for energy, will travel though the walls into the adjoining area i.e. a bedroom or landing.

Changing the spacing of the UFH pipework for the same delivery temperature and flow from the ASHP/Boiler allows for different room temperatures and losses/gains.  This is why a room by room heat lose calculation is done, you can take into account the usage and the seasonal variations.

As an example, image that you have one loop that does the living room and downstairs cloakroom.

Water enters the pipe at say 35°C and exits at 30°C.  The cloakroom may only have 3m² of exposed wall, the other 3 are inside the house.  The living room may have 3 exposed walls, with only one within the house, so 50m² exposed to the outside.

Depending on which way the flow goes, the cloakroom may be getting water entering the loop at either 35° or 30°C, so may be either too hot or too cold if the pipe spacing is the same as the living room.

The problems start when designers just put in standard UFH pipework spacing and control it all by having multiple loops, each with their own thermostat and flow controller.  This is simpler to design, but harder to installer and a pig to control effectively.

 

You may well find that a fixed spacing will work well enough, but without knowing the  details, one cannot be certain.

So do those calculations, they are easy enough, just tedious.  It is what spreadsheets are for.

But you can to a great degree just manipulate the flow rate through individual loop to correct for this. Increase or decrease the flow changes the delta T and therefore the mean flow temp. Anything below 20W/m2 heating requirement a 1 or 2 degree change in mean flow tamp has a big impact on heat output. Irrespective of pipe centres.

[Nickfromwales]

4 minutes ago, JohnMo said:

But you can to a great degree just manipulate the flow rate through individual loop to correct for this. Increase or decrease the flow changes the delta T and therefore the mean flow temp. Anything below 20W/m2 heating requirement a 1 or 2 degree change in mean flow tamp has a big impact on heat output. Irrespective of pipe centres.

Surface contact (cross sectional area of the pipe > surrounding concrete) determines how effectively the transfer of energy is, and if you want to effect cooling this becomes a valid point of consideration. Heating is barely worth talking about and almost manages itself; just look at examples of folk on here at all ends of the spectrum, some at 100mm o/c and other at 400mm o/c, some with a buffer / some without, and so on. Nobody has yet yelled for help as their system is 'out of control' for heating.

Closer o/c means the slab will be more reactive and pipe is cheap as chips, but I also cannot experiment in my clients homes! Belt & braces (for the cost difference vs risk) will always be my choice.

Cooling is the 'enemy' as the input flow temps need to avoid condensation risks, ergo you can only effect a certain amount of 'change' over x period of time, and the less CSA and volume, the worse (more elongated) that becomes. Further to this, the dwelling type has further effects which need to be factored in, and then you also need to understand if auxiliary cooling via AHU's can bolster the effect and manage the times between the slab coming into useful play. Cooling likely needs injecting at the small hours, so as to have some kind of momentum for the sunny morning to midday, and the kick in the knackers there is only some of it can be dealt with from PV then.

One client uses the cooling 'long & low' (so nigh-on constant flow of "cold-ish" water through the UFH)but I also specified an intelligent AHU which speeds up the MVHR fan speeds when it detects cold water input into the heat exchanger, eg to increase the volume of cooled air (heat energy) conveyed, and I'm still gathering feedback / data as to how that works out in an occupied dwelling but controls seem to be the bug bear with this type of flip/flop setting. Trying to get something simple and recognisable to hand over to Joe Public is a challenge!

 

I am very impressed with the Steibel Eltron ASHP we installed recently, but more so with the controls. DHW goes direct off the ASHP and cooling / heating of the UFH goes through a digital blending set (fed from buffer when either warm or cold) which then goes direct to AHU. The advantage here is that I can send 7^oC water to the AHU to max out its cooling capabilities vs minimising air flow speed rates, and the blended sum goes to the UFH so I can decide that to be 16^oC, simultaneously.

 

I think a few of the more boffin-like members on here have come up with the same solution, but this one is out of the box and more 'fit for human consumption'. I just wish there were more hours in the day so I could read everything written on here about the subject! In the meantime, I may just go on to recommend and employ the (very expensive) Steibel setup, as it actually works out as being value for money when you look at it as a holistic and comprehensive turnkey heating and cooling arrangement.

[Shaun McD]

1 hour ago, Nickfromwales said:

The exact reason that on my current project (a fully certified Passivhaus) I am designing this issue out; manipulation of where flow goes first, selecting which pipes get insulated before reaching their target 'zones' and also by selecting different o/c's in different spaces according to discipline. One thermostat planned per floor but with a very tight hysteresis so the second there is fluctuation (up or down) the systems can respond quickly (as quickly as a PH can) and mitigate against over / under shoot. Solar gain over shoot is the offender that my efforts will be largely focussed on, heating is a doddle to deal with.  

 

Nice point on insulating loop feed lines, would never think on these things! Is handling which area gets flow first just position on manifold?

 

1 hour ago, Nickfromwales said:

Surface contact (cross sectional area of the pipe > surrounding concrete) determines how effectively the transfer of energy is, and if you want to effect cooling this becomes a valid point of consideration. Heating is barely worth talking about and almost manages itself; just look at examples of folk on here at all ends of the spectrum, some at 100mm o/c and other at 400mm o/c, some with a buffer / some without, and so on. Nobody has yet yelled for help as their system is 'out of control' for heating.

Closer o/c means the slab will be more reactive and pipe is cheap as chips, but I also cannot experiment in my clients homes! Belt & braces (for the cost difference vs risk) will always be my choice.

Cooling is the 'enemy' as the input flow temps need to avoid condensation risks, ergo you can only effect a certain amount of 'change' over x period of time, and the less CSA and volume, the worse (more elongated) that becomes. Further to this, the dwelling type has further effects which need to be factored in, and then you also need to understand if auxiliary cooling via AHU's can bolster the effect and manage the times between the slab coming into useful play. Cooling likely needs injecting at the small hours, so as to have some kind of momentum for the sunny morning to midday, and the kick in the knackers there is only some of it can be dealt with from PV then.

One client uses the cooling 'long & low' (so nigh-on constant flow of "cold-ish" water through the UFH)but I also specified an intelligent AHU which speeds up the MVHR fan speeds when it detects cold water input into the heat exchanger, eg to increase the volume of cooled air (heat energy) conveyed, and I'm still gathering feedback / data as to how that works out in an occupied dwelling but controls seem to be the bug bear with this type of flip/flop setting. Trying to get something simple and recognisable to hand over to Joe Public is a challenge!

 

I am very impressed with the Steibel Eltron ASHP we installed recently, but more so with the controls. DHW goes direct off the ASHP and cooling / heating of the UFH goes through a digital blending set (fed from buffer when either warm or cold) which then goes direct to AHU. The advantage here is that I can send 7^oC water to the AHU to max out its cooling capabilities vs minimising air flow speed rates, and the blended sum goes to the UFH so I can decide that to be 16^oC, simultaneously.

 

I think a few of the more boffin-like members on here have come up with the same solution, but this one is out of the box and more 'fit for human consumption'. I just wish there were more hours in the day so I could read everything written on here about the subject! In the meantime, I may just go on to recommend and employ the (very expensive) Steibel setup, as it actually works out as being value for money when you look at it as a holistic and comprehensive turnkey heating and cooling arrangement.

 

all very interesting, I have yet to get into too much detail on the cooling side! Main factors so far are the solar gain redistribution and opting for a heat pump (if possible) with a cooling function. On that note, again on pipe spacings, using flow rates and pipe spacing to help not over heat areas with higher solar gain seems clear, but on the flip side, when it comes to cooling the slab by pumping around 13-16deg C water, would it not be a plus point to have more pipe, i.e. less spacing? The principle that the more water in the slab will allow for more heat extracted? Having pipes at 300 centers are bound to be less efficient at cooling the slab than at 100mm? I am sure there is maths that can be done on how much heat can be extracted by volume of water i guess

[SteamyTea]

1 hour ago, Shaun McD said:

I am sure there is maths that can be done on how much heat can be extracted by volume of water i guess

There is, but it is based on mass flow rates.

Luckily in the case if water, mass and volume are equal mathematically.

2 hours ago, Nickfromwales said:

Nobody has yet yelled for help as their system is 'out of control' for heating.

They have in here, frequently.

[Nickfromwales]

3 hours ago, Shaun McD said:

Nice point on insulating loop feed lines, would never think on these things! Is handling which area gets flow first just position on manifold?

One pipe leaving will be flow at the manifold temp, and the return loop will obvs be at the lower temp. Deciding which pipe runs where offers some minimal but additional manipulation of this distribution. In a PH or thereabouts it does become almost moot as the slab will almost completely uniformly acclimatise and there will be very little difference between the two. I only insulate the pipes going to the far side of the dwelling from the manifold, mostly to keep whatever is in the pipe, in the pipe, until I want it 'out'.

[SteamyTea]

8 minutes ago, Nickfromwales said:

One pipe leaving will be flow at the manifold temp, and the return loop will obvs be at the lower temp

Unless used for cooling.

(I may have missed something posted up earlier about this, the beach wear is a distraction).

[Nickfromwales]

1 hour ago, SteamyTea said:

Unless used for cooling.

(I may have missed something posted up earlier about this, the beach wear is a distraction).

Flow will be flow, regardless of duty, so the energy in the pipe gets preserved and delivered where it needs to go to.

[SteamyTea]

15 minutes ago, Nickfromwales said:

Flow will be flow, regardless of duty, so the energy in the pipe gets preserved and delivered where it needs to go to.

Won't the thermostats/blending valves behave a bit odd if they see a cooler temperature entering?

[DanDee]

6 hours ago, Shaun McD said:

 

but on the flip side, when it comes to cooling the slab by pumping around 13-16deg C water, would it not be a plus point to have more pipe, i.e. less spacing? The principle that the more water in the slab will allow for more heat extracted?

 

Yes, in general I wish for both floor and ceiling/walls piping as the perfect solution to manage the cooling loads, and the different heating loads(once you go double the surface of the floor, at the same spacing, you have enough loops that can be off when load needs reducing, without different temps).

Whatever the benefits (extra low temp on heating, extra cooling power) this cannot be done for every customer at their expense, only for those that really want something like this.

[JohnMo]

On 29/05/2023 at 12:09, Nickfromwales said:

Surface contact (cross sectional area of the pipe > surrounding concrete) determines how effectively the transfer of energy is,

Not completely there is also the downward and upward heat transfer, how quickly the heat or cool is moved either upwards or downwards. Very good insulation below the pipes makes a difference.

 

On 29/05/2023 at 13:22, Shaun McD said:

cooling the slab by pumping around 13-16deg C water, would it not be a plus point to have more pipe, i.e. less spacing? The principle that the more water in the slab will allow for more heat extracted? Having pipes at 300 centers are bound to be less efficient at cooling the slab than at 100mm

You would think so but, you also have to careful you stay a over condensation temperature. More cold water in floor equals a cold floor and risk of condensation. Plus your heat pump will alway manage the delta T between flow and return, get the floor too cold your heat pump permissive to start cooling again may not achieved, so your room go hot, cold,hot, cold.. it's all a balancing act.

 

Ran my UFH on cooling today. Start temperature of the water in the floor was 20.5 degs.  End of the day at 5pm when I turn off the system the water was returning at 17 degrees.

 

Comparing the house temp today and yesterday in similar conditions, sun all day.  Yesterday pumping the UFH around all day, but not cooling, living room was 27 degs, by this time, today cooling on 22, but feels cooler. Set ASHP with a 12 deg flow temp, (tried higher but delta T could not manage it) so ran once and didn't give a permission to restart.  ASHP ran most of the day, switching of about a 10 times over a 9 hour period, living room 22 degrees, but felt cooler. That's with floor U value of 0.09 and 300mm spacing and circa 100mm concrete screed.

[Shaun McD]

8 minutes ago, JohnMo said:

Not completely there is also the downward and upward heat transfer, how quickly the heat or cool is moved either upwards or downwards. Very good insulation below the pipes makes a difference.

 

You would think so but, you also have to careful you stay a over condensation temperature. More cold water in floor equals a cold floor and risk of condensation. Plus your heat pump will alway manage the delta T between flow and return, get the floor too cold your heat pump permissive to start cooling again may not achieved, so your room go hot, cold,hot, cold.. it's all a balancing act.

 

Ran my UFH on cooling today. Start temperature of the water in the floor was 20.5 degs.  End of the day at 5pm when I turn off the system the water was returning at 17 degrees.

 

Comparing the house temp today and yesterday in similar conditions, sun all day.  Yesterday pumping the UFH around all day, but not cooling, living room was 27 degs, by this time, today cooling on 22, but feels cooler. Set ASHP with a 12 deg flow temp, (tried higher but delta T could not manage it) so ran once and didn't give a permission to restart.  ASHP ran most of the day, switching of about a 10 times over a 9 hour period, living room 22 degrees, but felt cooler. That's with floor U value of 0.09 and 300mm spacing and circa 100mm concrete screed.

 

Great information, maybe I am naive but that seems like a great result, free daytime PV running the HP in cooling mode and seeing upwards of 5 degc temp offset, id be delighted with that!

[Nickfromwales]

4 hours ago, JohnMo said:

Ran my UFH on cooling today. Start temperature of the water in the floor was 20.5 degs.  End of the day at 5pm when I turn off the system the water was returning at 17 degrees.

 

Comparing the house temp today and yesterday in similar conditions, sun all day.  Yesterday pumping the UFH around all day, but not cooling, living room was 27 degs, by this time, today cooling on 22, but feels cooler. Set ASHP with a 12 deg flow temp, (tried higher but delta T could not manage it) so ran once and didn't give a permission to restart.  ASHP ran most of the day, switching of about a 10 times over a 9 hour period, living room 22 degrees, but felt cooler. That's with floor U value of 0.09 and 300mm spacing and circa 100mm concrete screed.

From 27 to 22 is what we call "a result". 27 must have been quite unbearable? Do you not have a means of initiating cooling automatically (via a dumb stat which monitors the upper temps) eg to facilitate a policy of prevention vs cure? You should be able to run at lower cool flow temps if this is 'grabbed' early. Why did you have to 'run' it, why didn't it run itself?

[JohnMo]

9 hours ago, Nickfromwales said:

Do you not have a means of initiating cooling automatically (via a dumb stat which monitors the upper temps) eg to facilitate a policy of prevention vs cure? You should be able to run at lower cool flow temps if this is 'grabbed' early. Why did you have to 'run' it, why didn't it run itself

Hi Nick, yesterday was me commissioning the ASHP on cooling, so ran it manually. Now have the thermostat setup to cooling mode, so it's fully automated. So basically at the moment the setting is to start cooling if the house is above 20 degrees, at any time between 8am and 5pm.

 

When the cooling season is over, I will flip thermostat to its heating setting and flip the summer/winter selection switch for the ASHP to winter.

[Nickfromwales]

12 minutes ago, JohnMo said:

Hi Nick, yesterday was me commissioning the ASHP on cooling, so ran it manually. Now have the thermostat setup to cooling mode, so it's fully automated. So basically at the moment the setting is to start cooling if the house is above 20 degrees, at any time between 8am and 5pm.

 

When the cooling season is over, I will flip thermostat to its heating setting and flip the summer/winter selection switch for the ASHP to winter.

Great. Do you mind me asking which stat you ended up going with, please? 

[JohnMo]

14 minutes ago, Nickfromwales said:

Do you mind me asking which stat you ended up going with, please

I'm using a Computherm Q7RF.