Heat Pumps - post here.

Latro · 27-05-2018 7:10pm

Just don't fall for claim that to run HP you need excellent insulated house.
I'd claim the opposite. If you have passive house level of thermal envelope don't get heap pump and definitely not GSHP. It will never pay back for itself.
Heat loss is heat loss, regardless of heating system.
If you lose almost 0 heat you can run anything to compensate for that near 0 loss. In these cases the cheaper the system the better imo.

Water John · 27-05-2018 7:19pm

You still have Building Regs to pass.
If you want to run a small log stove, all day, that's fine.

Latro · 27-05-2018 7:32pm

Water John wrote: »

You still have Building Regs to pass.
If you want to run a small log stove, all day, that's fine.

I wouldn't consider running log stove of any size in any house a cheap solution unless you have free supply of fuel and even then all the labor involved... oh well that would't be for me but I'm sure some people would enjoy.

Water John · 27-05-2018 9:21pm

I was sort of joking originally but I just see ceramic stoves on The Great House Revival. It absorbs a good bit of the heat and lets it out gradually. So the house would be warm in the morning.

RedPandaDan · 30-05-2018 12:53pm

Hi Folks,

So I've been informed that my gas boiler is on its last legs and needs to be replaced. I've been looking at A2W heat pumps and was wondering if they are worth fitting to a small existing house? I wouldn't be in a position to install under floor heating, can they be used with rads?

House built in 2000
3 Bed Semi
80 m² total
D1 BER

Most stuff I've found about them online talks about the savings in large houses. Would anyone have a rough estimate how much it'd cost?

Thanks in advance!

30-05-2018 1:13pm

If your house isn't extremely well insulated and air tight then you'd be far better off getting a modern 98% efficient gas Boiler, your old one is probably 70% that will save you 28% right there + change provider and you could save even more.

A HP is very expensive and the true life remains unknown, 10 years I hear, there's no pay back if that's the case.

A brand new build I'd say fair enough.

So if it were I, than I'd probably get a good efficient boiler and put the rest into insulation.

RedPandaDan · 30-05-2018 1:30pm

Deleted User wrote: »

If your house isn't extremely well insulated and air tight then you'd be far better off getting a modern 98% efficient gas Boiler, your old one is probably 70% that will save you 28% right there + change provider and you could save even more.

A HP is very expensive and the true life remains unknown, 10 years I hear, there's no pay back if that's the case.

A brand new build I'd say fair enough.

So if it were I, than I'd probably get a good efficient boiler and put the rest into insulation.

Thanks Mad_Lad, appreciate it.

30-05-2018 2:16pm

No bother, I'm no expert so just offering my opinion , perhaps maybe get professional advise as to what is the best way to go, it might also be better electronic controls to go with your new boiler if you get one.

Carrickbeg · 30-05-2018 9:42pm

[Deleted User] wrote: »

If your house isn't extremely well insulated and air tight then you'd be far better off getting a modern 98% efficient gas Boiler, your old one is probably 70% that will save you 28% right there + change provider and you could save even more.

A HP is very expensive and the true life remains unknown, 10 years I hear, there's no pay back if that's the case.

A brand new build I'd say fair enough.

So if it were I, than I'd probably get a good efficient boiler and put the rest into insulation.

New gas boiler is the one for you. Heat pumps for A rated homes and work best with UFH.

SeanHarty · 31-05-2018 10:27pm

Deleted User wrote: »

No bother, I'm no expert so just offering my opinion , perhaps maybe get professional advise as to what is the best way to go, it might also be better electronic controls to go with your new boiler if you get one.

Use to work in the technical office of a large heating and plumbing merchants and your spot on in this case a high efficiency boiler is the way to go.

Shefwedfan · 15-06-2018 3:35pm

I seen mentioned earlier on another forum about Air to Air heat pump. Longer term I want to move from oil and was looking at air to water but it is retrofit and don't want to change radiators.

I was thinking of swapping to air to air. Does anyone have any experience of these systems?

SeanHarty · 15-06-2018 4:38pm

Shefwedfan wrote: »

I seen mentioned earlier on another forum about Air to Air heat pump. Longer term I want to move from oil and was looking at air to water but it is retrofit and don't want to change radiators.

I was thinking of swapping to air to air. Does anyone have any experience of these systems?

Do you want to change from oil for a cost saving measure for tree hugging on?

Best value for money for someone with oil is a efficient boiler and their cheap now and off the shelf.

Retro fitting a heat pump system CAN BE an expensive exercise

Shefwedfan · 15-06-2018 5:28pm

SeanHarty wrote: »

Do you want to change from oil for a cost saving measure for tree hugging on?

Best value for money for someone with oil is a efficient boiler and their cheap now and off the shelf.

Retro fitting a heat pump system CAN BE an expensive exercise

Your wisdom is great.....oh wise one.....

Expensive you say? I thought they would have just installed free of charge....with a few trees in garden so I can hug them

SeanHarty · 15-06-2018 6:49pm

Wasn't trying to take the piss out of you or anything, I have a degree in renewables so if anyone's a tree hugger it's me...

But with my degree and years experience working in the heating and plumbing industry selling these things I guess I would know a thing or two..

But please do plant the trees. The rate we are cutting them down is shocking.

Carrickbeg · 30-07-2018 12:49pm

Im told that the COP of heat pumps for heating hot water as oppose to space heating is 2.
Is this correct?

MOTM · 30-07-2018 12:52pm

Carrickbeg wrote: »

Im told that the COP of heat pumps for heating hot water as oppose to space heating is 2.
Is this correct?

How long is a piece of string?

Look for test results to EN16147 or Ecodesign technical documentation showing nWh efficiency from the supplier / manufacturer.

However, space heating efficiency in heatpumps (particularly for lower temperature applications such as underfloor heating) will likely be better than water heating efficiency as hot water is required at highter temperatures.

o1aa · 01-08-2018 6:18pm

Hi guys,

I have the air to water system installed by Dimplex and trying to figure out the hear curve.
People are saying to have it on low rather than high. Not sure what's meant by it?? I've attached my heat curve below, could someone explain to me what the numbers mean? I'm so confused!

Also would love to hear some insight on the heat curves that worked in your houses! Thanks a mill.

01-08-2018 10:23pm

o1aa wrote: »

Hi guys,

I have the air to water system installed by Dimplex and trying to figure out the hear curve.
People are saying to have it on low rather than high. Not sure what's meant by it?? I've attached my heat curve below, could someone explain to me what the numbers mean? I'm so confused! Also would love to hear some insight on the heat curves that worked in your houses! Thanks a mill.

haven't a clue what all that means but just curious as to what type of house the A2W system was installed, older house, very energy efficient ?

Cost including installation and what was involved ?

Water John · 01-08-2018 11:25pm

Could be wrong but my reading of the first one is that when the outside temp is very low, the output side is 45C, but as outside temp goes above 0C it tapers down to a 40C output.
The second simply tells Total Operating Times for the Compressor, the time for space heating, the time the compressor is producing hot tap water, the number of hours the back up electric heating element had to come on, to boost the compressor.

o1aa · 02-08-2018 5:40am

@Mad_Lad it's a new house in the estate. A2 rated.

Water John wrote: »

Could be wrong but my reading of the first one is that when the outside temp is very low, the output side is 45C, but as outside temp goes above 0C it tapers down to a 40C output.
The second simply tells Total Operating Times for the Compressor, the time for space heating, the time the compressor is producing hot tap water, the number of hours the back up electric heating element had to come on, to boost the compressor.

Thanks a lot for this! And why would the compressor come on to produce hot tap water? I thought I the water goes below certain degree that I set it at, the heat pump(starts working outside) and heats up the water to go to desired level.

I've been told that the compressor shouldn't run more than the heating , as this costs money. In my case the compressor is working more. Any idea why?

And when does the backup heater start working ?

I'm c a newbie in this and it's not so statight forward as heating up the house with gas!

Water John · 02-08-2018 7:34pm

Not an authority of HPs. The back up heater only comes on in very cold weather to supplement the HP. Usually HPs have a split system. The main one heats water to 40/45C for space heating either under floor or rads. A second unit takes water to 55/60C for tap/shower water.
The higher temp you take water to the less efficient the unit is. So the unit doing the space heating operates at a better efficiency (COP) than the tap water heating.

Condenser · 04-08-2018 8:47pm

Water John wrote: »

Not an authority of HPs. The back up heater only comes on in very cold weather to supplement the HP. Usually HPs have a split system. The main one heats water to 40/45C for space heating either under floor or rads. A second unit takes water to 55/60C for tap/shower water.
The higher temp you take water to the less efficient the unit is. So the unit doing the space heating operates at a better efficiency (COP) than the tap water heating.

This is incorrect. The system is not split. If you have ufh downstairs and rads upstairs the heat pump will heat the water to the temp required by the highest temp system meaning your overall COP will drop. So if you use rads that need 45c and your ugh needs 30c your efficiency is dictated by the need to satisfy the radiators and will drop performance by at least 35%.

The heat curve also needs to be set up to reflect your heating system so if your rads need 50c when it's 0c outside in order to heat the house then you set it to reflect this. If you have ufh alone 30c might be sufficient at 0c and 25c might be sufficient at 15c.

Regarding back up immersions, they tend to come on far more regularly in systems that require high temps such as radiators, have small hot water tanks usually less than 300l and air to water systems where lower outside temps put much more pressure on the system and defrosting is an issue.

GraceKav · 11-08-2018 4:26pm

Hi all, Hoping I have this in the right spot - we're just going out to tender on a new build which will have a heat pump - we've had conflicting advice about whether or not we should keep this as a PC sum item - Thoughts? Thanks.

Wearb · 11-08-2018 4:42pm

GraceKav wrote: »

Hi all, Hoping I have this in the right spot - we're just going out to tender on a new build which will have a heat pump - we've had conflicting advice about whether or not we should keep this as a PC sum item - Thoughts? Thanks.

Have a read here https://www.askaboutmoney.com/threads/warning-all-the-pc-provisional-sum.166542/

Carrickbeg · 11-08-2018 4:57pm

GraceKav wrote: »

Hi all, Hoping I have this in the right spot - we're just going out to tender on a new build which will have a heat pump - we've had conflicting advice about whether or not we should keep this as a PC sum item - Thoughts? Thanks.

Get your heat loss calculations done for your house and then get a properly sized system to meet your needs...

GraceKav · 11-08-2018 5:00pm

Wearb wrote: »

Have a read here https://www.askaboutmoney.com/threads/warning-all-the-pc-provisional-sum.166542/

Thanks Wearb, I think I've read this before but good to have a refresher as its been a while. I may have misunderstood the engineer as it sounded like they were planning to let the builder spec the heat pump which I wasn't happy with for all the reasons detailed in that article and more. We're sitting down to go through the full tender and construction drawings (which we have commissioned in full) next week and fingers crossed I've just misunderstood them. Just wanted to get a sensecheck that if I haven't misunderstood them, I'm not being unreasonable in wanting to spec 100% the heat pump and the supplier/model etc for the builder.

AnswerIs42 · 12-08-2018 5:38pm

Does anyone have their heat pump installed upstairs or in the roof? We are thinking of installing it in the gable wall upstairs so it would mean maintenance guys would need a ladder or scaffolding (Health & Safety reasons??) to service it from the outside. I'm trying to see if their are other issues with keeping the heat pump off the ground floor that should be factored in.

John.G · 21-08-2018 10:56am

KCross wrote: »

OK, I'm familiar with all those metrics. They are available on the main screen of the system as well. There isn't a great deal of benefit to being able to see them from the app to be honest.

Once the system is running and stable the way you want it it is fully automatic and there is no real requirement to remotely access it.

Even if you changed some of the settings it takes time for the system to "rebalance" so doing it from the app doesn't buy you anything really.

It should be free, tbh.

Do any of the ASHP manufacturers display the time on defrost cycle(s) and the compressor energy required since defrosting has such a huge effect on the COP/SPF of the installation or has any user any data/info on this?.

Latro · 23-08-2018 5:42pm

I retrofitted 9kW A2W in to my house last month.

I will post here how it goes once the heating season starts.
So far we use it to heat DHW 280L tank.
Water temp 45 degrees, at the moment cost according to the manufacturer app is 12-15 cents per day. 2 adults+1 child.

The target is to have constant 20-21 degrees throughout the day. The heating window initially is going to be from 7am to midnight with downtime for the night to avoid low external temperatures.

Some stats:
2 storey detached house with attached garage(heated), in total around 200sqm heated surface. Finished in 2013 to pre 2008 regs. Timber frame.
Ground floor: open plan, office, utility, toilet, garage.
First floor: 3 bedrooms, 2 en suite, bathroom, TV/play room, hot press, small walk-in wardrobe.

Insulation:
-walls 6 inch fibreglass
-slab: no idea here since I bought the house at near builders finish state and never had opportunity to see whats in it.
-attic: initially there was 10(4+6) inches of fiberglass, upgraded with another 2 layers of 6 inch of the same in criss-cross pattern. In total 22 inches. Heh I know, a lot, but it is relatively cheap material and easy to DIY.

Windows: known brand PVC, double glazed.
Ventilation: traditional holes in the walls, I'm contemplating upgrading to heat recovery, maybe next year, depends on this season heating bills.

Steel, double Radiators: 8 fairly large downstairs and 6 of the same upstairs plus 4 towel rails in total.

Fingers crossed it is enough. If not I will add few more as this option would be far cheaper than going underfloor at this stage. Also easy DIY-able with timber frame.

3 zones for heating: ground floor, 1st floor and DHW tank. No zone thermostats at all, TRVs on all rads.

Heat pump: 9kW, monoblock, inverter, single phase with cooling option and desktop PC or android phone loging/monitoring/operating bells and whistles.
One of the latest model of big, known brand.

John.G · 24-08-2018 11:40am

Latro wrote: »

I retrofitted 9kW A2W in to my house last month.

I will post here how it goes once the heating season starts.
So far we use it to heat DHW 280L tank.
Water temp 45 degrees, at the moment cost according to the manufacturer app is 12-15 cents per day. 2 adults+1 child.

The target is to have constant 20-21 degrees throughout the day. The heating window initially is going to be from 7am to midnight with downtime for the night to avoid low external temperatures.

Some stats:
2 storey detached house with attached garage(heated), in total around 200sqm heated surface. Finished in 2013 to pre 2008 regs. Timber frame.
Ground floor: open plan, office, utility, toilet, garage.
First floor: 3 bedrooms, 2 en suite, bathroom, TV/play room, hot press, small walk-in wardrobe.

Insulation:
-walls 6 inch fibreglass
-slab: no idea here since I bought the house at near builders finish state and never had opportunity to see whats in it.
-attic: initially there was 10(4+6) inches of fiberglass, upgraded with another 2 layers of 6 inch of the same in criss-cross pattern. In total 22 inches. Heh I know, a lot, but it is relatively cheap material and easy to DIY.

Windows: known brand PVC, double glazed.
Ventilation: traditional holes in the walls, I'm contemplating upgrading to heat recovery, maybe next year, depends on this season heating bills.

Steel, double Radiators: 8 fairly large downstairs and 6 of the same upstairs plus 4 towel rails in total.

Fingers crossed it is enough. If not I will add few more as this option would be far cheaper than going underfloor at this stage. Also easy DIY-able with timber frame.

3 zones for heating: ground floor, 1st floor and DHW tank. No zone thermostats at all, TRVs on all rads.

Heat pump: 9kW, monoblock, inverter, single phase with cooling option and desktop PC or android phone loging/monitoring/operating bells and whistles.
One of the latest model of big, known brand.

Its not clear to me at least but have you upgraded your house insulation (just) before you installed the HP and what form of heating are you converting from?.
It will be very interesting to see how fast the house will take to heat up after being off from midnight to 0700 each night bearing in mind that you will now have ~ 30 deg rads with ~ 50% output of the 50 deg rating.
The best of luck with your installation.

Latro · 24-08-2018 12:49pm

John.G wrote: »

Its not clear to me at least but have you upgraded your house insulation (just) before you installed the HP and what form of heating are you converting from?.
It will be very interesting to see how fast the house will take to heat up after being off from midnight to 0700 each night bearing in mind that you will now have ~ 30 deg rads with ~ 50% output of the 50 deg rating.
The best of luck with your installation.

The rads water temperatures will be on a curve from 40 to 50 degrees between 15 to -5 degrees outside. As I'll be gaining experience with the system I'll adjust it if they are too low or too high.

Before HP installation I was running something like pellet boiler with large hopper but instead of pellet it used small pea coal. It was cheap enough system to run (about 600-700/year) but the necessity of cleaning it every 10-12 days from sludge made my garage completely unusable because of dust everywhere.
I wanted perfect clean garage so I decided to get rid of it and do a full renovation. I'd probably keep the old system if I had totally separate room dedicated for the purpose but that option would be quite expensive.
Also I don't need to store large pile of coal bags in my shed anymore.
The water temperature I ran on that was too 45-50 degrees but it was circulating 24/7 with TRVs cutting off rads when too warm.

Before I moved in the system was designed to take oil boiler and I didn't modify it at all just connected the other boiler with 3 way valve.
Now the heat pump is connected directly to it as if it was oil.

I upgraded insulation in the attic in 2013 when we moved in. And now with HP install I didn't do any modifications at all.

Carrickbeg · 24-08-2018 3:03pm

Latro wrote: »

I retrofitted 9kW A2W in to my house last month.

I will post here how it goes once the heating season starts.
So far we use it to heat DHW 280L tank.
Water temp 45 degrees, at the moment cost according to the manufacturer app is 12-15 cents per day. 2 adults+1 child.

The target is to have constant 20-21 degrees throughout the day. The heating window initially is going to be from 7am to midnight with downtime for the night to avoid low external temperatures.

Some stats:
2 storey detached house with attached garage(heated), in total around 200sqm heated surface. Finished in 2013 to pre 2008 regs. Timber frame.
Ground floor: open plan, office, utility, toilet, garage.
First floor: 3 bedrooms, 2 en suite, bathroom, TV/play room, hot press, small walk-in wardrobe.

Insulation:
-walls 6 inch fibreglass
-slab: no idea here since I bought the house at near builders finish state and never had opportunity to see whats in it.
-attic: initially there was 10(4+6) inches of fiberglass, upgraded with another 2 layers of 6 inch of the same in criss-cross pattern. In total 22 inches. Heh I know, a lot, but it is relatively cheap material and easy to DIY.

Windows: known brand PVC, double glazed.
Ventilation: traditional holes in the walls, I'm contemplating upgrading to heat recovery, maybe next year, depends on this season heating bills.

Steel, double Radiators: 8 fairly large downstairs and 6 of the same upstairs plus 4 towel rails in total.

Fingers crossed it is enough. If not I will add few more as this option would be far cheaper than going underfloor at this stage. Also easy DIY-able with timber frame.

3 zones for heating: ground floor, 1st floor and DHW tank. No zone thermostats at all, TRVs on all rads.

Heat pump: 9kW, monoblock, inverter, single phase with cooling option and desktop PC or android phone loging/monitoring/operating bells and whistles.
One of the latest model of big, known brand.

12 - 15 cents to heat 280L of hot water? That's 1kwh on my electricity charges...

John.G · 24-08-2018 4:09pm

Carrickbeg wrote: »

12 - 15 cents to heat 280L of hot water? That's 1kwh on my electricity charges...

Its possibly referring to the energy required to supply water at 45C for the three occupants from a fully heated 280 Litre tank?......if one just assumes a average hot water demand of 50 Ltrs/person/day then energy (water input) required is
150*(45-15)/860, 5.23 Kwh. HP input ~ 1 Kwh, COP (5.23/1), 5.23, quite possible one would think with the present high ambient temperatures and no need for HP defrost?.

Latro · 24-08-2018 5:06pm

John.G wrote: »

Its possibly referring to the energy required to supply water at 45C for the three occupants from a fully heated 280 Litre tank?......if one just assumes a average hot water demand of 50 Ltrs/person/day then energy (water input) required is
150*(45-15)/860, 5.23 Kwh. HP input ~ 1 Kwh, COP (5.23/1), 5.23, quite possible one would think with the present high ambient temperatures and no need for HP defrost?.

That's exactly what I meant. Also water in the tank probably never drops to 15 degrees at this time of the year. And there is some left over heat in it from previous day.
Seems there is 0 reasons to go solar once you have HP with hot water on demand any time of the year.
But anyway, it is warm outside so I don't get too exited yet.
The real test will be Dec,Jan and Feb.

Not sure how to post a picture here.

https://imgur.com/a/fDmScez

John.G · 25-08-2018 7:56am

Latro wrote: »

That's exactly what I meant. Also water in the tank probably never drops to 15 degrees at this time of the year. And there is some left over heat in it from previous day.
Seems there is 0 reasons to go solar once you have HP with hot water on demand any time of the year.
But anyway, it is warm outside so I don't get too exited yet.
The real test will be Dec,Jan and Feb.

Not sure how to post a picture here.

https://imgur.com/a/fDmScez

As you say "The real test will be Dec,Jan and Feb." as @ A0 W45 the output may be < 6.0 Kw and @ A-3 W45 it may be as low as 5.0 Kw. Was there any particular reason why you went for a 9 Kw unit as against say a 12 KW (or higher) especially when you selected VSD.

Latro · 25-08-2018 10:30am

According to my own calculations based on fuel used with old system my house needs between 60 to 100kWh per day to compensate for the heat loss.

100kWh/5kW=20h and that is when temperature dips to -5(very rare).
And at this cold the compensating curve is set do raise the temperature to 50 degrees.

If it gets even colder for that odd week once per few years I don't mind boosting it with built-in immersion, it should not affect heating cost long term too much.
Also there is the stove in the living room to give additional kick but I'm against that form of heating unless you have free fuel. I use it maybe 2 times a year and not even for heating purposes.
Anyway, that's all theory, I'll keep you posted with real life numbers as winter progresses.

stoves1 · 27-08-2018 8:53pm

I am presently considering a works on my house a standard 3bed semi detached, the proposal is to get the house insulated incl external walls, windows doors etc underfloor heating with aluminium rads upstairs which at the end i have been guaranteed an A3 rating, i am happy to go ahead but wondering will a mitsubshi ecodan 5kw heat pump along with a 150 litre pre plumbed hot water cyclinder be suffice to offer us the hot water we need for showers and the heat we will require in winter, i would appreciate your comments

Latro · 27-08-2018 9:32pm

What is heated sqm area of the house?
A3 house requires between 50 and 75kWh/1sqm/year.
I'm no expert at BER but I'd think 70-80% of that is spent on heating.
You can work your numbers from there.
Don't be too optimistic with HP efficiency and there should be no problem with figuring it out. I'd assume 2.6-2.7 average winter COP.

Water John · 27-08-2018 10:21pm

Be very sure the correct insulation is going under the floor if you are installing UFH.

John.G · 28-08-2018 6:54am

stoves1 wrote: »

I am presently considering a works on my house a standard 3bed semi detached, the proposal is to get the house insulated incl external walls, windows doors etc underfloor heating with aluminium rads upstairs which at the end i have been guaranteed an A3 rating, i am happy to go ahead but wondering will a mitsubshi ecodan 5kw heat pump along with a 150 litre pre plumbed hot water cyclinder be suffice to offer us the hot water we need for showers and the heat we will require in winter, i would appreciate your comments

I know you hope to get a A3 rating but have you any idea of your heating requirements now based on Gas/oil usage.? A 5 KW unit seems very optimistic bearing in mind that its output will be as low as 3.0 KW on cold winter days, and also regular defrosting must be kept in mind. Has a heating "expert" sized the HP for you?, IMO the electric auxiliary heating element could be in use quite a lot if you go for this unit. If it was my house I would be far happier to install at least the 8.5 KW unit and possibly bigger.

John.G · 01-09-2018 7:46am

John.G wrote: »

Do any of the ASHP manufacturers display the time on defrost cycle(s) and the compressor energy required since defrosting has such a huge effect on the COP/SPF of the installation or has any user any data/info on this?.

Some interesting info here including info on above even though its for one period....Nov 2016.
https://passivehouseplus.ie/magazine/feature/the-ph-guide-to-air-source-heat-pumps

Easter Sunday · 01-09-2018 10:31am

Hi John,
Not sure but this is a big thing for me too.

After doing a lot of research and speaking to multiple installers( most of whom could not answer my defrost cycle question to my satisfaction), we think we will go with a CTC as it only defrosts when needed, it has much wider (anti corrision) coils at the back to reduce frosting and it’s pv panel ready.

Apparently others ice up easily due to tight coils, they rust and they defrost every few minutes when the temperature drops below a certain degree whether it’s needed or note. Also most others are not pv panel ready, despite what installers tell you.

Please note I am no expert, just building my new house and my advice is based on what I believe to be true and what makes sense to me.

John.G wrote: »

Some interesting info here including info on above even though its for one period....Nov 2016.
https://passivehouseplus.ie/magazine/feature/the-ph-guide-to-air-source-heat-pumps

John.G · 02-09-2018 8:25am

I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."

Easter Sunday · 02-09-2018 12:30pm

I was told by several different installers ( who each installed only 1 brand) that their systems were compatible with pv panels as long as they were wired for pv.

I wasn’t quite convinced as a sales man for one of these brands at the Ideal Homes Exhibition told me that they weren’t currently ready but that a new model next year probably would be.

I then spoke to an installer who fits several brands ( including these aforementioned brands ) and he told me that neither of the brands I had researched is pv panel ready ( something to do with an immersion I think). He had nothing to lose by telling me that as he installs them anyway...he wasn’t pushing any particular brand on me -just explaining the difference.

So just be sure you’re happy with the capability of your brand / model.

quote="John.G;107968753"]I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."[/quote]

John.G · 03-09-2018 3:20pm

Easter Sunday wrote: »

I was told by several different installers ( who each installed only 1 brand) that their systems were compatible with pv panels as long as they were wired for pv.

I wasn’t quite convinced as a sales man for one of these brands at the Ideal Homes Exhibition told me that they weren’t currently ready but that a new model next year probably would be.

I then spoke to an installer who fits several brands ( including these aforementioned brands ) and he told me that neither of the brands I had researched is pv panel ready ( something to do with an immersion I think). He had nothing to lose by telling me that as he installs them anyway...he wasn’t pushing any particular brand on me -just explaining the difference.

So just be sure you’re happy with the capability of your brand / model.

quote="John.G;107968753"]I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."

[/QUOTE]

The normal Solar PV can have a diverter installed that will send any surplus power to a electric immersion in a hot water cylinder so I assume that you are saying that this power could be diverted to the HP auxiliary heating element instead and therefore the HP should be able to recognize this and accept the switched surplus and that this is what is meant by "PV Panel ready"?.

MENACE2010 · 05-09-2018 3:06pm

Hi
check the type of hot-water cylinder you are going to use , some of them will have a heating element in it , connect the divert to the heating element and it will heat the water in the tank. .the heatpump should detect the hot water temperature and decide to kick in or not. (Regardless my HP will cycle the hot water to avoid Legionnaires disease to 70 degrees ..so there will be some extra cost )

search for PV batteries instead, there is a supplier in Ireland that sells modular battery storage that can work with the HP and the house .. so you store the excess in battery storage and use it at night for lighting and telly(s) and hot water generation for the HP.

the challenge is though the numbers don't add up .. I have been through this with a PV installer and the payback time is Years .. and then some ..I dont have that spare cash to burn on a lofty and green initiative ..

WLad · 05-09-2018 5:20pm

Has anybody set up any type of smart system with these heat pumps? Ours is a dimplex air to water and wondering how easy it is to change over to something like alexa controlling sonoff switches or something similar. Thanks.

MENACE2010 · 06-09-2018 10:14am

Hi
I tried , eg researched our HP has smartlink.. but that only governs the heating not the hotwater. .. there a "port" you can dabble with but my other half is not that thrilled with "experiments" .. we also have a webinterface , but I'm not sure how "hackable" that is .. i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Google for the service manual for your heatpump and you will discover where is what, and what you can steer .

WLad · 06-09-2018 10:22am

MENACE2010 wrote: »

Hi
I tried , eg researched our HP has smartlink.. but that only governs the heating not the hotwater. .. there a "port" you can dabble with but my other half is not that thrilled with "experiments" .. we also have a webinterface , but I'm not sure how "hackable" that is .. i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Google for the service manual for your heatpump and you will discover where is what, and what you can steer .

Exact same as me, my track record with experimenting and then breaking things isn't great so she doesn't trust me

The hot water wouldn't bother me, I am really just looking to make it so that I can get Alexa or whatever to turn on the heating in specific zones before I get home. I will research anyway, thanks for your input!

KCross · 06-09-2018 10:36am

MENACE2010 wrote: »

Hi
i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Does your heat pump not do weather compensating?
I thought that was standard enough... i.e. a temp gauge outside that the HP monitors and adjusts its run time accordingly.

WLad wrote: »

I am really just looking to make it so that I can get Alexa or whatever to turn on the heating in specific zones before I get home. I will research anyway, thanks for your input!

HP's dont really work that way. If you are sending it a signal at 5pm to have a room warm for you by 6pm you are going to be disappointed. HP's need hours to build up the UFH temp and then release it.

You are thinking of the old style oil burner and rad type system where you turn it on and it fires out 60C heat within minutes. HP's deliver <30C to the UFH and then it takes time for that to "seep" through to the house.

You shouldnt really be turning anything on or off on the heat pump. Set it to the temp that is comfortable for you and your house and then let the HP manage that itself.

Heat Pumps - post here.

Comments