Heat Pumps - post here.

Calahonda52

Frozen Veg wrote: »

There seems to be some horror stories going around re bills with a2w but perhaps that's all down to poor air tightness.

also undersized, by poor A/T and poor BER is an issue

sebdavis

Hi, just wondering if anyone here has invested in a DHW heat pumps? I was looking at solar for hot water but think this might be a better option, just wondering if anyone has invested and if worth it? thanks

graememk

sebdavis wrote: »

Hi, just wondering if anyone here has invested in a DHW heat pumps? I was looking at solar for hot water but think this might be a better option, just wondering if anyone has invested and if worth it? thanks

I think I've seen the ads on facebook too and I think I know what you're talking about. A bit sparse on the specs, and dimensions. Around 3k for it though.

If ran on night rate, it would be quite cheap to run.

How do you currently heat your water?

sebdavis

graememk wrote: »

I think I've seen the ads on facebook too and I think I know what you're talking about. A bit sparse on the specs, and dimensions. Around 3k for it though.

If ran on night rate, it would be quite cheap to run.

How do you currently heat your water?

Oil or electric
Standard hot water cylinder which is maybe 100ltr
Electric majority of the time because we always run out of water

graememk

sebdavis wrote: »

Oil or electric
Standard hot water cylinder which is maybe 100ltr
Electric majority of the time because we always run out of water

If you were thinking of changing your water tank anyway it could be an option. It's a 250L tank.

Only theorising, never seen them in person. So more research would be needed.

Another option is to get a bigger tank and have it plumbed to your oil so that it can call for heat from the oil independent from the heating controls.

Eg you use hot water, control system detects that and fires up the boiler. And only the hot water tank gets the heat, not the house.

- that option might be feasible even with your current tank.

It costs to heat water by oil to be 5-6c/kwh compared to the immersion at 16/17c

Water John

Only solar worth considering is PV. There are grants with that. Link it primarily to a larger hot water tank. Use night rate as a top up.

sebdavis

graememk wrote: »

If you were thinking of changing your water tank anyway it could be an option. It's a 250L tank.

Only theorising, never seen them in person. So more research would be needed.

Another option is to get a bigger tank and have it plumbed to your oil so that it can call for heat from the oil independent from the heating controls.

Eg you use hot water, control system detects that and fires up the boiler. And only the hot water tank gets the heat, not the house.

- that option might be feasible even with your current tank.

It costs to heat water by oil to be 5-6c/kwh compared to the immersion at 16/17c

Larger tank is required, kids getting bigger so more & more water getting used which means filling the tank on night rate it will all be gone very quickly in morning.

I have the ability to heat the water off the oil while not heating the house but it;s more a manual process that auto. I do have auto for rest of house with Drayon Wiser, I don't think they have an option for water to kick it in.....

I talked to guys many years ago and I think it was 3k for the DHW system, was too expensive at that stage, just wondering if they have reduced at all? I seen lots of post in UK facebook group so they seem fairly common over their

Calahonda52

sebdavis wrote: »

Hi, just wondering if anyone here has invested in a DHW heat pumps? I was looking at solar for hot water but think this might be a better option, just wondering if anyone has invested and if worth it? thanks

.
What exactly do you you mean by a DHW HP?
.
A HP has a SCOP of maybe 2.0 hot water, depends on what the temperature lift is, so at night rate it might be 5 cents kWh.

Re the Solar thermal, it can be a bit of an issue in terms of the way it is designed and implemented in domestic situations in Ireland so maybe a non runner, however in Europe it is used with large, stratified, thermal storage tanks.
.
https://www.jenni.ch/home-345.html
.
https://www.jenni.ch/files/jenni/inhalte/pdf/Produkte/certificate_Stratification_efficiency.pdf
.
The best example I have seen here in Ireland is where a guy buried a large precast tank in his front garden, and heats the water in it with solar thermal, so every erg of sun energy is captured.
He then fitted a W2W HP and the SCOP has never been less than 8.

sebdavis

Calahonda52 wrote: »

.
What exactly do you you mean by a DHW HP?
.
A HP has a SCOP of maybe 2.0 hot water, depends on what the temperature lift is, so at night rate it might be 5 cents kWh.

Re the Solar thermal, it can be a bit of an issue in terms of the way it is designed and implemented in domestic situations in Ireland so maybe a non runner, however in Europe it is used with large, stratified, thermal storage tanks.
.
https://www.jenni.ch/home-345.html
.
https://www.jenni.ch/files/jenni/inhalte/pdf/Produkte/certificate_Stratification_efficiency.pdf
.
The best example I have seen here in Ireland is where a guy buried a large precast tank in his front garden, and heats the water in it with solar thermal, so every erg of sun energy is captured.
He then fitted a W2W HP and the SCOP has never been less than 8.

http://glenergy.ie/hot-water-heat-pumps/

This is what I mean, as far as I can see they are called DHW heat pump but could be wrong

graememk

sebdavis wrote: »

http://glenergy.ie/hot-water-heat-pumps/

This is what I mean, as far as I can see they are called DHW heat pump but could be wrong

Oh good a decent brochure + Spec sheet. Has a 500w compressor, and a 1500w immersion - also a coil to be able to heat from oil too.

As you currently have some manual control of heating hw from oil, - that should be easy enough to automate, esp with a new tank.

Have you an idea where you will source and vent Air from for the heat pump?

As you have said you need to do something, as your current system isn't adequate.

Time to get some quotes in!

Get one from the suppliers of the heat pump hot water and also get one that would be a "standard" well insulated HW tank. (that can call for heat from oil independently from the heating controls)

I have no idea on price etc, but I am just interested in the tech.

edit:, in addition
The installation on the dairy farm is clever, the vacuum pumps generate waste heat that then is captured by the hot water heat pump, which it means its not having to work as hard as it would if it was taking cold outside air in.

This would have a knock on effect in a house, if you were taking warm house air and pulling the heat out of it. Heat pumps move energy, not create it.

Taking heat out of the air in winter wouldnt be ideal as then you will have to run your heating longer.
In the summer it would cool the house.

sebdavis

graememk wrote: »

Oh good a decent brochure + Spec sheet. Has a 500w compressor, and a 1500w immersion - also a coil to be able to heat from oil too.

As you currently have some manual control of heating hw from oil, - that should be easy enough to automate, esp with a new tank.

Have you an idea where you will source and vent Air from for the heat pump?

As you have said you need to do something, as your current system isn't adequate.

Time to get some quotes in!

Get one from the suppliers of the heat pump hot water and also get one that would be a "standard" well insulated HW tank. (that can call for heat from oil independently from the heating controls)

I have no idea on price etc, but I am just interested in the tech.

edit:, in addition
The installation on the dairy farm is clever, the vacuum pumps generate waste heat that then is captured by the hot water heat pump, which it means its not having to work as hard as it would if it was taking cold outside air in.

This would have a knock on effect in a house, if you were taking warm house air and pulling the heat out of it. Heat pumps move energy, not create it.

Taking heat out of the air in winter wouldnt be ideal as then you will have to run your heating longer.
In the summer it would cool the house.

When I looked before he mentioned the boiler room itself which is in the house and the air in it is hotter. That is right beside the room which the DHW would reside so easy to pipe in

Also potentially a sun room which during the summer months can be like an oven. Bit of work but a bungalow so could be connected via attic but could* cool the sun room at the same time as heating water

Ideal would be the ability to pull hot air from boiler room during winter when the boiler is going and from sun room during the summer as the boiler would normally not be running.

planes01

Doing some ground work at the side of the house as putting down a concrete patio area. Have uncovered the pipes coming from the ground where we drilled down for geothermal heat pump.
Will it be ok to cover these with the cement or should we leave them accessible.
Thanks

KCross

planes01 wrote: »

Doing some ground work at the side of the house as putting down a concrete patio area. Have uncovered the pipes coming from the ground where we drilled down for geothermal heat pump.
Will it be ok to cover these with the cement or should we leave them accessible.
Thanks

You wont need to access them until you need to access them!


Covering them with concrete wont matter to the system right now but if you need to chase a leak its obviously going to be a problem then.

If you do concrete over them I'd try to, at least, get a decent layer of stone over them and then put red/yellow tape on top of that and then concrete on top of that so that if you do need to dig at a later date that you can do it without hitting the pipes as you are busting the concrete.

Calahonda52

as above and I would leave an expansion joint, felt or plastic, each side of the pipes so the breakout would be controlled when you have the HM 580 in digging!

Stefs_42

Thinking of upgrading from oil heating to heat pump. House has B2 rating. Walls pumped, double glazing and PV system in place. Yearly consumption of oil - approx 1000 Liters. Would I save much with heat pump considering I meet all requirements? What kind of extra insulation would be needed to get max efficiency from heat pump? Would spray foam insulation in attic be any good? What else should I consider replacing, apart from getting aluminium rads?

MicktheMan

Stefs_42 wrote: »

Thinking of upgrading from oil heating to heat pump. House has B2 rating. Walls pumped, double glazing and PV system in place. Yearly consumption of oil - approx 1000 Liters.
1. Would I save much with heat pump considering I meet all requirements?
2. What kind of extra insulation would be needed to get max efficiency from heat pump?
3. Would spray foam insulation in attic be any good?

1. Not enough info to answer. You might not save anything or it might not even be up to the job!
2. Depends on where & how the heat is currently being lost. It's not all about insulation either in our mild but windy climate. Do you know what your airtightness is like?
3. Unlikely

Stefs_42

MicktheMan wrote: »

1. Not enough info to answer. You might not save anything or it might not even be up to the job!
2. Depends on where & how the heat is currently being lost. It's not all about insulation either in our mild but windy climate. Do you know what your airtightness is like?
3. Unlikely

How do I measure heat loss? Is there a survey to be done, similar to BER?

Isnt all heat raising to the top, eventually escaping through roof, windows, etc? Hence I was thinking of packing up roof with spray foam.

MicktheMan

Stefs_42 wrote: »

1. How do I measure heat loss? Is there a survey to be done, similar to BER?

2. Isnt all heat raising to the top, eventually escaping through roof, windows, etc? Hence I was thinking of packing up roof with spray foam.

1. Yes, a heat loss survey will test your house for the primary heat loss mechanisms and make recommendations on how best to address.

2. Yes warm air is more buoyant and will rise but you have different types of actual heat loss from the house. No point in insulating the house (e.g. roof) if significant air leakage paths are not addressed and most of your heat loss is through air leakage rather than conduction through the roof. This is why a proper survey is worth considering.

Stefs_42

MicktheMan wrote: »

1. Yes, a heat loss survey will test your house for the primary heat loss mechanisms and make recommendations on how best to address.

2. Yes warm air is more buoyant and will rise but you have different types of actual heat loss from the house. No point in insulating the house (e.g. roof) if significant air leakage paths are not addressed and most of your heat loss is through air leakage rather than conduction through the roof. This is why a proper survey is worth considering.

Nice! We re getting somewhere. Have you got any links for heat loss surveyors, please?

MicktheMan

Stefs_42 wrote: »

Nice! We re getting somewhere. Have you got any links for heat loss surveyors, please?

Maybe. Depends on where you're based. Pm sent

wicklow_hunter

Anyone tried programming there heat pump to run ufh on the night rate tariff and if so did it pull down the average daily consumption.

My Danfoss does allow the hot water to be timed to go on the night rate but not the heating.

I’m guessing it’s an efficiency thing to maintain the temp of the floors as opposed to long on off cycles

ecowise

I can't comment on savings achieved by switching to a night only tariff from a mixed tariff but it can work to run on night tariff only. It depends very much on the energy rating of your house and the storage capacity of the medium containing the pipework. We have been running our GSHP on night rate only for 20 years and it costs slightly over1 euro per sq. m. per year to heat the house. We have solar panels for hot water and the house is designed to benefit from any solar gain available. At the coldest time of the year we frequently augment our heat, in the evenings mainly, with a wood burning stove which is positioned to benefit a large portion of the house (fortunately we have our own supply of wood). Our house was built well in excess of building regulations at the time with respect to insulation values, having a wall u value around 0.14 W/m2K. However we did not put enough insulation under the floor screed and we lose more heat than we should by that route. Probably your best option is to try it for a while and under different conditions to see how it works out but it is possible in theory.

Ballylad

MicktheMan wrote: »

Maybe. Depends on where you're based. Pm sent

could you also send me details of a heat loss surveyor. thnks

Gael23

What brand of A2W system is recommended?

BryanF

Gael23 wrote: »

What brand of A2W system is recommended?

It’s like asking ‘Which car would you recommend’?

the_amazing_raisin

Has anyone here any experience with getting a Dimplex heat pump serviced? Ours is due it's first out of warranty service and I'm wondering how much it typically costs

Also I think we're in need of a new water circulation pump as ours sounds like a hammer drill on full power sometimes. Anyone have any idea how much one will costs? I'm guessing it'll be a few hundred

the_amazing_raisin

Gael23 wrote: »

What brand of A2W system is recommended?

I'd go with a company that has been building heat pumps for a while, basically any company that makes air conditioners will have experience

You'll also want to check the support network available, not much use if there are no service agents or parts suppliers

I've a Dimplex A Class and while it works, I'm not convinced it'll last a long time, it's 4 years old and I don't see it going for 15-20 years like some people manage with their heating

Maybe the newer units are better but I'll be going with a different brand next time

DubLad69

Hey guys,

We are considering buying a new build with a dimplex Air to Water Heat pump and underfloor heating. We are concerned about a few things.

1. Does the water get hot enough for a really hot bath/shower?

2. How slow to respond is the system? I love going to bed in a cold room, and usually leave the window open. With my current gas boiler and a nest, I can still wake up in a warm room. Will this be possible with a heat pump system?

3. Will the house stay warm even if it gets to minus 3 outside?

0lddog

DubLad69 wrote: »

Hey guys,

We are considering buying a new build with a dimplex Air to Water Heat pump and underfloor heating. ....

Hi DubLad,
There may be some other considerations to take into account.
Have a read of https://www.boards.ie/vbulletin/showthread.php?t=2058139594

Calahonda52

Is there UFH throughout?
Whats the BER?
Have you an air permeability test result for the house?

UFH normally maintains an even temperature, its not designed for on off so it wont replicate you gas/nest.
whats the exact spec on the HP?
What do you mean by really hot shower, water should be no more than 60 in the tank.
It will meet that.
house will be warm at -3, it just depends on the pump as to what the COP will be at that point