Heat Pumps - post here.

Cosmia

Thanks for that Ted, and for the recommendation re the other forum...think I'll copy my query there and see if I get a few more hits...

The_Morrigan

Cosmia wrote: »

Thanks for that Ted, and for the recommendation re the other forum...think I'll copy my query there and see if I get a few more hits...

I'll move it over for you - no point having two live threads on the same subject.

seaniefr

Cosmia wrote: »

I'm considering buying a property with this heating system...this will be the only source of heating the water and air in the house. It is a new build with an A3 BER rating, approx 1000sq ft and will be heated using a Dimplex air source heat pump. I have absolutely no experience with this system, nor do I know anyone who has used one and my knowledge is limited to what I've gleaned from the internet (very little!)

I got an info sheet from Dimplex which makes grand claims as to their cost efficiency and environmental benefits, but I'm primarily concerned with two questions:

a)will I actually be warm in winter without it costing an arm and a leg?

b) are they really cost efficient?

The info sheet says that they are 382% efficient compared with natural gas which is 92% efficient... and therefore the running costs are approximately half of what gas would be...this seems too good to be true!! Is it?

I actually have no problem paying the same type of bills I might reasonably expect had I natural gas, but I fear I may actually end up paying more.

I rented a place years ago that had electric storage heating, and swore then that I would never under any circumstances go back to electricity...
I really like the house and want this to be a good thing, but don't want to regret it either...

I'd really appreciate any feedback! thanks!

Ask them how the heat pump cope when the outside air temp drops below 4 degrees some use a back up electrical element to make up the difference and your electricity bill will rise if we have another bout of hard weather.
It should have a soft starter also which would help with the electricity consumption also.
My neighbor has one of those although it's about 6 years old now and it let him down during the cold weather spell a fee years ago

BryanF

HP threads merged

AntrimGlens

So its just a few days short of a year since we turned on the heating to dry out the house and I took a reading last night and since 1st Sept 13 we have used 5580kwh. We didn't actually move in until 18th Dec so no real hot water usage until then. house is 3100sq ft and no mhrv. I have no split between hot water or heating usage.
12kw waterkotte hp with geo thermal and ufh and to be honest I didn't keep that tight an eye on heating as i should have. Working it out based on what I would be paying for electric it would be costing me £2.67 per day or £975 for the year, which is slightly less than what the govt are paying me through the renewable heat incentive annually, although it's actually not costing me anything to power it thanks to the hydro turbine.

Extremely happy with the performance, compared to what we were previously paying for oil in the old house which was only 1100sq ft.

MortgageBroker

Anybody have a link or name & number of the geothermal trouble shooter people? Did a search & not sure who everybody is referring to, thanks

ArraMusha

For a new build are heat pumps just too expensive right now? I have been researching the pros and cons of ground and air heat pumps and although I like and understand the theory of their operation, the upfront cost right now are just too large when compared to a Firebird kerosene boiler.

Concerns:
1. It could take up to 15 years or more to repay the cost depending on the house design (insulation and air tightness).
2. There are also a lot more things that can go wrong and the fact that WHEN things go wrong I want to be able to either fix it myself or ring a plumber, not have to ring Germany and wait for an answer.
3. The running costs are approx half that of oil, for a correctly installed system..again this depends on house design (insulation and air tightness)
4. If you go with a heat pump, underfloor heating is the most practical due to surface area and the lower temps achievable...so its a big upfront commitment as oil burners work well using rads and not so well with underfloor due to the time lag.

If anyone has experience of heat pumps for a few years, can you please post below.

BryanF

HP threads merged

froshtyv

ArraMusha wrote: »

For a new build are heat pumps just too expensive right now? I have been researching the pros and cons of ground and air heat pumps and although I like and understand the theory of their operation, the upfront cost right now are just too large when compared to a Firebird kerosene boiler.

Concerns:
1. It could take up to 15 years or more to repay the cost depending on the house design (insulation and air tightness).
2. There are also a lot more things that can go wrong and the fact that WHEN things go wrong I want to be able to either fix it myself or ring a plumber, not have to ring Germany and wait for an answer.
3. The running costs are approx half that of oil, for a correctly installed system..again this depends on house design (insulation and air tightness)
4. If you go with a heat pump, underfloor heating is the most practical due to surface area and the lower temps achievable...so its a big upfront commitment as oil burners work well using rads and not so well with underfloor due to the time lag.

If anyone has experience of heat pumps for a few years, can you please post below.

There are plenty of installers in Galway who have been installing air-to-water heat pumps for several years. If you need some names and numbers drop me a pm. Local back-up service is key to any type of system.

For your query about cost, an oil boiler with a new build will require solar along with a compatible cylinder which when you add up the costs ends up being similar to the cost of a heat pump system.

MortgageBroker

MortgageBroker wrote: »

Anybody have a link or name & number of the geothermal trouble shooter people? Did a search & not sure who everybody is referring to, thanks

bump... a guy named tony wrote to me from one of the firms about 10 days after I wrote then asked when he could call out and never heard back - anybody know a person in Dublin?

My heatpump is giving me bills about the size of the mortgage!

MENACE2010

Hi Arramusha

i have a airsource heatpump.. we're going into our second winter now with and for the full year we have an average electricity bill of 133 euro's per month.. that's everything .(cooking /TV/lights/pc's/ Heat recovery).

We have a good relationship with local plumber and the installers. So far we had some teething problems in the beginning ( getting to know the best settings .) .

The main fact is that heatpump with underfloor heating does not work the same as oil.. its a climate heating rather than instantaneous ( like what you would have with oil boiler and rads) so the overall temperature will remain the same .
we have set it so that the pump kicks in during the night (early morning) and goes into reduced temperature mode during the day ( 18C) and after 4 PM it goes up to 20C .
We have a small stove to "boost" . In the summer time heating is off entirely .. house gets solar gain. I would not go back again to oil.. shop around there are enough installers in Ireland I can PM you our guys if needed

So far we are very happy ..with it all its works and have great service .

BarneyMc

MENACE2010 wrote: »

Hi Arramusha

i have a airsource heatpump.. we're going into our second winter now with and for the full year we have an average electricity bill of 133 euro's per month.. that's everything .(cooking /TV/lights/pc's/ Heat recovery).

We have a good relationship with local plumber and the installers. So far we had some teething problems in the beginning ( getting to know the best settings .) .

The main fact is that heatpump with underfloor heating does not work the same as oil.. its a climate heating rather than instantaneous ( like what you would have with oil boiler and rads) so the overall temperature will remain the same .
we have set it so that the pump kicks in during the night (early morning) and goes into reduced temperature mode during the day ( 18C) and after 4 PM it goes up to 20C .
We have a small stove to "boost" . In the summer time heating is off entirely .. house gets solar gain. I would not go back again to oil.. shop around there are enough installers in Ireland I can PM you our guys if needed

So far we are very happy ..with it all its works and have great service .

Can I just ask if you use the night tarrif for electricity? Also did you use a concrete or screed on your ground floor and what thickness? Thanks.

MENACE2010

Hi
we have night tarrif.. we have on the ground floor from the foundation up > 200MM EPS insulation with 75MM screed on top of that..

Sandman777

MENACE2010 wrote: »

Hi
we have night tarrif.. we have on the ground floor from the foundation up > 200MM EPS insulation with 75MM screed on top of that..

What are the rates for your day and night tarrifs?

I have a geo HP and im running on standard rate atm and wondering is it worth switching to night rate? My HP usage for heating and dwh atm is averaging around 9 to 10 kwh per day!

MENACE2010

Sandman777 wrote: »

What are the rates for your day and night tarrifs?

I have a geo HP and im running on standard rate atm and wondering is it worth switching to night rate? My HP usage for heating and dwh atm is averaging around 9 to 10 kwh per day!

Hi. I need to check, I have the pump setup that it only generates hot water at night and during the daytime it runs reduced temperature. I need to check what the usage is

Sandman777

MENACE2010 wrote: »

Hi. I need to check, I have the pump setup that it only generates hot water at night and during the daytime it runs reduced temperature. I need to check what the usage is

Ok thanks.

Mine Runs in mornings 6:00am to 8:30am and is set back during the day as we are at work

Then 4:30pm to 10:00pm in evenings and setback till 6am again. Usually only runs for few hrs in evening unless very cold out.

House set to 21 deg.

Hp will only run for hot water when tank drops below set temp and is currently costing about 20 cent or less per day!

MENACE2010

Hi
now all houses are different so this is "guess estimate" .. I presume you have underfloor heating ? as that detail is missing ;o}

now the pump is set for 2.5 hrs in the morning and 5 1/2 at evening time and at 21C .
My observation would be that A. the pump needs to do more to make up for the temprature deficit in the morning and evening . Our set-back is 18C from 9 am to 17:00 PM . After that its 20C downstairs and 18.5 upstairs( we have thermostats on the loops to close them when needed)
B 21 degrees C .. now again everyone enjoys comfort at a different level but if the house cools down to 18C during the day by the time its nearly 9 or 10 its up right temperature ...could be wrong .

Our installer told me not to block the HP during the night time or even in the daytime to ensure you "top up" the heat , the longer the pump is off the bigger the temperature difference will be that the system needs to overcome.

Heatpumps are " climate" heating systems , its not instant like oil fired boiler. you need to find the right level of heat for your house

We have our heatpump only for one year and we are going into our second winter.. at the moment I have set the pump low (our pump works with heating curve) and tweak it upwards until we have the right temperature.. Last winter the house was frequently too hot ( 22C and 23C ) now we are on 19C - 20 C average it has not frozen for real yet ;o}

hopefully this all helps a bit .. Its difficult as a lot of posts are stating high costs .. but fail to mention the environment the heatpump is used in .. what the insulation values are etc our monthly cost will be around 130 - 140 euros.. what I'm happy with

night rate is okay as long as you think about it .. eg run the dishwasher in the morning .. instead of the evening and start the wash either after 11 or before 9. the better alternative is to get AAA appliances

sheff the ref

From the feedback supplied by those who are using heatpumps, it is obvious that the level of insulation is key to keeping costs down. Maintaining a level of temperature is far more difficult if the heat is escaping

Condenser

sheff the ref wrote: »

From the feedback supplied by those who are using heatpumps, it is obvious that the level of insulation is key to keeping costs down. Maintaining a level of temperature is far more difficult if the heat is escaping

The insulation spec required is far too overstated. The fact is that the most important factors for a successful heatpump are the design of the collector and distribution system and also the controls used. The fact remains that the heatloss for a house remains the same whether using a heat pump or an oil or gas boiler but provided the previously mentioned items are designed correctly then the heat pump will be far cheaper to run and the difference even more pronounced the larger the heatloss.
Unfortunately this is gotten wrong more often than it is right so your installers track record is key.

Mixupat

Condenser wrote: »

The fact is that the most important factors for a successful heatpump are the design of the collector and distribution system and also the controls used.

Condenser, thanks for your post. I am looking at GSHP with 2 reputable suppliers currently. Based on your response, could you elaborate on how to verify the system design they propose and also controls used to verify the success of the system they install. It would be great to know what to ask them and whats needed.

MENACE2010

Agree with condenser.. good point, the challenge is though to find the correct and proper installer.. most people will be newbie's ( unless you have build mutliple houses that is ) as you would only build once. So far my supplier has been good. the implementation from my builder and plumber less so .. ( cold spots on the floor etc) overall its all working to satisfaction and within my expectation of cost.

Sandman777

MENACE2010 wrote: »

Hi
now all houses are different so this is "guess estimate" .. I presume you have underfloor heating ? as that detail is missing ;o}

now the pump is set for 2.5 hrs in the morning and 5 1/2 at evening time and at 21C .
My observation would be that A. the pump needs to do more to make up for the temprature deficit in the morning and evening . Our set-back is 18C from 9 am to 17:00 PM . After that its 20C downstairs and 18.5 upstairs( we have thermostats on the loops to close them when needed)
B 21 degrees C .. now again everyone enjoys comfort at a different level but if the house cools down to 18C during the day by the time its nearly 9 or 10 its up right temperature ...could be wrong .

Our installer told me not to block the HP during the night time or even in the daytime to ensure you "top up" the heat , the longer the pump is off the bigger the temperature difference will be that the system needs to overcome.

Heatpumps are " climate" heating systems , its not instant like oil fired boiler. you need to find the right level of heat for your house

We have our heatpump only for one year and we are going into our second winter.. at the moment I have set the pump low (our pump works with heating curve) and tweak it upwards until we have the right temperature.. Last winter the house was frequently too hot ( 22C and 23C ) now we are on 19C - 20 C average it has not frozen for real yet ;o}

hopefully this all helps a bit .. Its difficult as a lot of posts are stating high costs .. but fail to mention the environment the heatpump is used in .. what the insulation values are etc our monthly cost will be around 130 - 140 euros.. what I'm happy with

night rate is okay as long as you think about it .. eg run the dishwasher in the morning .. instead of the evening and start the wash either after 11 or before 9. the better alternative is to get AAA appliances

Ya cheers, get to get others experiences!
Ya i have underfloor on both floors, Airtightness result 1.1 and BER A3.

Good points about the temp drop during the day and at night, HP is setback 3 deg during these times so if temp drop to 18 it will kick in but so far this hasnt happened! Im just getting to know the system so far and have a bit of reading up to do on heat curves etc.

Would you recommend i run the heating times closer together and for longer?

I presume that monthly cost is all in elec for house ya?

MENACE2010

H i
we have 20 normal and 19C set-back, it works fine at the moment , compared to last year when the house was too warm ( 21 - 22 C) .

I had a look at the usage ( thermia pump has an internet connection ;o) for last week

heating 59 hrs
hot water 8hrs

overall the pump has been on 68 hours of the week (various times) . most of them on night tarrif.

just as an experiment to see what this will do .. I'll report back on the electricity usage later in the day need to read my meter

The only "challenge" i find is that heatpumps need initially a lot of tweaking .. ifyou are so inclined to tweak that is no problem but if all the technical jargon is "swedish" or double dutch they can be a hard to manage.

Condenser

Mixupat wrote: »

Condenser, thanks for your post. I am looking at GSHP with 2 reputable suppliers currently. Based on your response, could you elaborate on how to verify the system design they propose and also controls used to verify the success of the system they install. It would be great to know what to ask them and whats needed.

Hi Mixupat,


A heat pumps efficiency is largely defined by how much work the compressor must do in order to raise the pressure of the refrigerant where you collect the energy to a pressure and therefore temperature at which you reject the energy. The closer these two points are the higher your COP will be.


So if I can gather energy from the ground by having a well designed collector that allows the temperature of the returning fluid to be as close to the ground temp as possible and have a distribution system which allows you to heat your house with the lowest output temperature possible you will achieve a high COP. So using a UFH system with a high density of pipework and short loops will allow you to run very low flow temps and achieve the same heat output as longer loops spaced wider apart but you will get a much improved COP.


Controls are the part where most heat pumps really fall down. Ideally you should have a good a system with good weather compensation ideally controlling on the return temperature. If you control off the flow temp slow pumps or blocked filters can slow the throughput of water which means the differential between inlet and outlet can get distorted and the room temp can be thrown off. Weather compensation will match the floor temp to the outside temp in order to fulfil your room temp. With this method you'll always be matching the heat load of the house and using the lowest output temp possible on a given day maximising COP.


If you decide to use stats (I don't recommend them) then it is imperative that a buffer tank is used in order to ensure full flow through the heat pump at all times even when the majority of stats are closed. It will also cut down on extreme short cycling where the heat pump is only running in order to satisfy one or two rooms.


Get the above right and you'll have a good system. Get even one of them wrong and you'll be sorry to ever set eyes on a heat pump.

MENACE2010

Hi
we have some thermostats on some loops not all of them, so we have some "middle ground" but in experience due to that we have no short cycling. what I do find is to get the "flow rate " correct is another tweakers hell ... the flow rate also determines what areas get more or less warm water in the loops ... even now I wonder if I have it right..

had a look at the my electricity usage , from august to October 32 % was used at night rate and 68% was used at day rate. now this is us getting sloppy with having dishwasher on before 11 pm and washing and dryer being used outside night rate.

Condenser

MENACE2010 wrote: »

Hi
we have some thermostats on some loops not all of them, so we have some "middle ground" but in experience due to that we have no short cycling. what I do find is to get the "flow rate " correct is another tweakers hell ... the flow rate also determines what areas get more or less warm water in the loops ... even now I wonder if I have it right..

had a look at the my electricity usage , from august to October 32 % was used at night rate and 68% was used at day rate. now this is us getting sloppy with having dishwasher on before 11 pm and washing and dryer being used outside night rate.

The constant opening and closing off your actuators are always going to distort the flow rates you get to different areas so that's a disadvantage of the set up you have. Depending on what % of floor area is off it may also slightly lower your COP.

sheff the ref

Relatively Speaking this has been a mild enough winter in comparison to the Winter of 2010. Would be interesting what the comparison might be if we had those conditions

MENACE2010 wrote: »

H i
we have 20 normal and 19C set-back, it works fine at the moment , compared to last year when the house was too warm ( 21 - 22 C) .

I had a look at the usage ( thermia pump has an internet connection ;o) for last week

heating 59 hrs
hot water 8hrs

overall the pump has been on 68 hours of the week (various times) . most of them on night tarrif.

just as an experiment to see what this will do .. I'll report back on the electricity usage later in the day need to read my meter

The only "challenge" i find is that heatpumps need initially a lot of tweaking .. ifyou are so inclined to tweak that is no problem but if all the technical jargon is "swedish" or double dutch they can be a hard to manage.

Rushy Fields

Not sure is this correct thread but i have a problem with my underfloor system heated by a nibe fighter 1145 with 300ltr cylinder in hotpress. digital thermostats upstairs in each bedroom (4) One of the bedrooms is cold.... not as warm as other rooms all 4 rooms set at 22 degrees on the stats. Actuators wiring have been checked and they seem to work. When i take off all actuators from manifold the cold room gets warm but another room adjacent to this room gets too warm 25-26degrees. Anyone ave words of wisdom? Heat pump set at heating curve 4. Had guy out with thermal imaging camera to check for leaks and any heat loss but none found.

Rushy Fields

See screenshot of heating curve. Should i change or not considering the weather lately

KCross

nealger wrote: »

Not sure is this correct thread but i have a problem with my underfloor system heated by a nibe fighter 1145 with 300ltr cylinder in hotpress. digital thermostats upstairs in each bedroom (4) One of the bedrooms is cold.... not as warm as other rooms all 4 rooms set at 22 degrees on the stats. Actuators wiring have been checked and they seem to work. When i take off all actuators from manifold the cold room gets warm but another room adjacent to this room gets too warm 25-26degrees. Anyone ave words of wisdom? Heat pump set at heating curve 4. Had guy out with thermal imaging camera to check for leaks and any heat loss but none found.

see here:
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