Heat Pumps - post here.

pandl · 17-02-2010 11:46pm

Hi onefinemorn
i was looking up the web site again and it def. says that for underfloor heating system the less heat loss between flow and return the better and the figures you have quoted he suggests are for a rad systems.I have no plumbing experience so if you would def suggest trying to balance the underfloor system i might give it a go

sandy_mac · 20-02-2010 2:30pm

gunner0098 wrote: »

Hi Mossy,

This is just a general reply to say that I'm having issues with very large ESB bills (last 2 month bill was €395!). I'm using a NIBE Fighter 1220. My installer tells me that it's not the heatpump that's causing the problem but I think overwise.
I do have insulation in the floors, walls and attic and I assume its been fitted correctly. But obviously looking at the other posts it's something that I'll have to check out.
The electrical measurements you have are very specific and I think I'll have to get my electrical in to check out my heatpump and see can he do similar.

Regards

Gunner0098

I have just moved into a rented house with a NIBE heat recovery unit for all heating/hotwater. My bill came in at £400 for 10 weeks in a small 1 person new-build house! I'm very energy conscious - I've never had a bill like this in my life, and just can't afford it. The house is very warm... to warm even. I've tried everything to turn the system down to reduce energy consumption, but it seems that it has a mind of its own, responding to an external temperature sensor and turning the heat on full all day& night if it thinks I might get cold! Do you know of any tricks? I'm on the verge of turning off the 'big switch', plugging in my elecric radiator, (which I can turn off when I'm at work!) and washing with kettles of water! So much for a modern, energy-efficient system! Any help would be greatly appreciated! The only advice I seem to get from Nibe is that the system is designed to regulate itself, so i feel totally out of control of my own energy use!
Thanks.

al2009 · 20-02-2010 6:55pm

Have the landlord contact a service company, it may be something small like too high a set temperature or it could be short of refrigerant, it's hard to tell without more info.

alec

sandy_mac · 21-02-2010 1:27pm

al2009 wrote: »

Have the landlord contact a service company, it may be something small like too high a set temperature or it could be short of refrigerant, it's hard to tell without more info.

alec

Thank you for responding!

I'm afraid the system has already been checked. I know the previous tenants (I live in a wee community) and they went down every road to reduce the bills, even having a NIBE consultant come up from Sheffield, but they said the system operating under the appropriate settings and working as it should. When asked if they thought the system was right for the house they replied 'no comment'. I figure that speaks volumes!

Don't get me wrong... the house is lovely and warm. BUT. I don't want the heaters to come on full blast when I'm not in the house. It's wasteful of energy and money. I was told by my housing association that it was 'modern living' to have your house warm all the time. Well, I'm afraid the dark ages of economical bills and saving the worlds resources suit me a whole lot better!

The housing association are now very unhelpful, and don't want to lose face by admitting that something is wrong. I know of at least 6 other people in this situation where I live. We don't really know where to turn for help. There appears to be NO way of controlling the system. We've tried all kinds of settings, turning the heat curve down etc - I've even insulated the external temperature sensor to fool the system into thinking it's warmer. I've monitored my consumption very closely, and it makes barely any difference at all. I don't know what else I can do!

al2009 · 21-02-2010 10:56pm

Most heat pumps come with a contact to fit a time clock to, maybe give Nibe a shout and find if that is possible, this way you can knock the unit off for a period of time without affecting the unit.

alec

sandy_mac · 21-02-2010 11:49pm

al2009 wrote: »

Most heat pumps come with a contact to fit a time clock to, maybe give Nibe a shout and find if that is possible, this way you can knock the unit off for a period of time without affecting the unit.

alec

That would be an ideal solution... I assumed it wasn't possible as they hadn't suggested it, but if you think that is a normal facility, i'll be on the phone to them in the morning!
Thank you for your advice!

Hicker09 · 23-02-2010 9:08am

Hi all,

Im will be starting a new build soon. The plan is to install a heat pump with under floor heating. But after reading some of the posts on here about the running costs and problems people have had im reconsidering. Im putting in 100mm of insulation in the cavity, 100mm under floor and insulated plasterboard on the inside. The pump we are getting is a nibe fighter 1245 for hot water and heating. Is this a good system? Or should i consider other systems?

Thanks in advance
Stephen.

satstheway · 25-02-2010 11:03am

windyboy wrote: »

Hi,

I am building an ICF 2 storey house (2800 sq ft) and have been given a quote for a Waterkotte 9.4kW geothermal heat pump. The plumber is local but I believe Nutherm supply the heat pumps. Has anyone here have any experience of this pump to advise me how it is performing.

Thanks,

Windyboy

Had nutherm turn on my heating an dec 08 and all well. few teething problems but they are always very quick to sort out the problem.
My house is 3300 sq ft and my esb bill was not big,:)
lots of hot water on demand,
as for the local plumber I would want to be sure of his know how on systems as its not cheap and i have seen some shoddy jobs:( out there "ground freezing" and so on

metalworker65 · 02-03-2010 12:01pm

satstheway wrote: »

Had nutherm turn on my heating an dec 08 and all well. few teething problems but they are always very quick to sort out the problem.
My house is 3300 sq ft and my esb bill was not big,:)
lots of hot water on demand,
as for the local plumber I would want to be sure of his know how on systems as its not cheap and i have seen some shoddy jobs:( out there "ground freezing" and so on

Watermote has inbuilt 6kw hidden element in heatpump. if it fails to perform as heatpump this will cut in unaware to you and leave you with massive esb consumption as this will have cop of 1:1. This info may not be pointed out to you when you purchase. I would suggest disconnecting this element initially.Does the output of heatpump quoted include this element in output figure given if so you are not getting what you are paying for.

thomur · 08-03-2010 3:01am

I have a Solterra 500. Was working fine until 1 month ago heating a 250sqm house. Now I can see my breath in the house most days. Constant 6-7 degrees in the house and pump running constantly. Was fantastic when running well. Dunstart no longer exist but got an engineer out and he said the system was running fine(input -output), but still no heat in the house. Thank god for the open fire. Does anyone know if this unit has a reset or is it something more serious.

08-03-2010 4:43am

thomur wrote: »

I have a Solterra 500. Was working fine until 1 month ago heating a 250sqm house. Now I can see my breath in the house most days. Constant 6-7 degrees in the house and pump running constantly. Was fantastic when running well. Dunstart no longer exist but got an engineer out and he said the system was running fine(input -output), but still no heat in the house. Thank god for the open fire. Does anyone know if this unit has a reset or is it something more serious.

How much of the system did the engineer check? Assuming UFH, does the manifold pump work, is the buffer cylinder getting hot, are the controls calling for heat?

If the (geo)pump's running constantly, where's the heat going?

It's possible that the system has got itself into a "flat battery" situation where the ground loop is so cold it can't extract any useful heat.

al2009 · 08-03-2010 10:28pm

there's no way that system is running fine if it's not heating the house, what exactly did the engineer check?

alec

thomur · 08-03-2010 11:11pm

Thanks for replying dolanbaker, he checked the pump only. I was away for a while so the pump was not used much over the Christmas. Have had it on 6 hours a day for 4 weeks and no increase in temp. I have 2 zones + water, he told me to knock off heating the water with it as it might be drawing the heat away from the zones. Currently I have a setpoint of 44(on the pump) and an incoming temp of 1 degree. The room thermostats are all calling for heat. Unfortunately the builder never gave me the manual so I dont know how to troubleshoot and I cant find it online. When you say flat battery do you mean the cold weather cooled the solution so much that it will take time to heat up. I dont know if the manifold is working but will check the buffer cylinder.

08-03-2010 11:50pm

Basically what I mean is that the ground where the pipes are is completly frozen!

An incoming temperature of only 1 degC would suggest that the ground had been cooled by the system.

Check the cylinder, if it's full of hot water then it's the UFH water circulating pump or in that area.

Are you getting any hot water out of the Geo pump? the compressor may be working but is it pressurised with refridgerant (one of the experts here will know the correct name for the liquid), the outgoing temp to the ground loop is always lower than the incoming one, if it isn't then the pump isn't working at all.

al2009 · 09-03-2010 10:08pm

Thomur

Even at 1c inlet so long as the pump has glycol in the cooling loop and the unit is set for this, heat can be extracted, this should be sufficient to start heating the house.

My own view would have been to leave only the hot water tank active and switch off the underfloor, the tank should be fairly fast to heat up and you could then switch on underfloor.

If the pump isn't running(should be evident from noise of compressor) then the unit may not be set up to allow cooling below 1c.

check pumps first for flow and correct operation, check valves are open to whatever section you want heated, if all these are ok then it points to the heatpump.

alec

thomur · 21-03-2010 12:53am

Thanks for the replies. Turns out I had 2 problems. A flap in one of the pipes coming out of the heat pump had stuck and was failing to make a circut. Secondly air had got into the system and the pressure was very low on the gauge(nearly 0 bar). I should have copped that myself. Still, you live and learn.

selfbuiler · 29-03-2010 11:52pm

Hi all,I Have just recived planing for my house and in 2 minds wether to go underfloor with a heat pump or with the traditional rads systems with oil.... Any ideas

30-03-2010 6:36am

selfbuiler wrote: »

Hi all,I Have just recived planing for my house and in 2 minds wether to go underfloor with a heat pump or with the traditional rads systems with oil.... Any ideas

Do a search in the main construction & planning forum for "UFH oil", you'll find lots of threads asking the same question.

soniag · 05-04-2010 9:49pm

Update on my heat pump...... It went on fire on Friday, yes flames and smoke. It's completely destroyed and we are going to have to have a whole new pump fitted, as soon as the insurance has OK'd it. So we have no heat or hot water now. The previous problem turned out to be a blown non-return valve and an intermittent fault in the wilo pump on the manifold, so wilo and valve changed and problem solved, don't think this next one will be quite so simple...... Any of you ever heard of a heat pump going on fire before??
Soniag

satstheway · 23-04-2010 11:24am

metalworker65 wrote: »

Watermote has inbuilt 6kw hidden element in heatpump. if it fails to perform as heatpump this will cut in unaware to you and leave you with massive esb consumption as this will have cop of 1:1. This info may not be pointed out to you when you purchase. I would suggest disconnecting this element initially.Does the output of heatpump quoted include this element in output figure given if so you are not getting what you are paying for.

To be honest they were very good and give me all the info and they said there was no need to ever connect the second cable (the one for the backup element). so i got the electrican to put a second switch on the wall and a second trip in for the element and it is always off:). but if in a failure i can at least have hot water

.
Only prob i ever heard of with waterkote is inaccurate time clock which might be a minute or 3 fast or slow a week.:mad:
anyone i know who went with nutherm seam to be happy unless anyone here has heard any probs

sunnymeade01 · 25-04-2010 4:17pm

Connacht wrote: »

Ok lads,
I know of a person in a ca. 4,000 sq ft house with only GSHP UFH heating and no back-up rads or OFCH or anything else.
Elec bills for y/e Feb 2009 - Euro 5,000 - day units 21,000 - night units 19,000.
Elec bills for y/e Feb 2008 - Euro 4,000 - day units 15,000 - night units 19,000.
Clearly, there is something VERY seriously wrong here.
Can anyone say what it is likely to be ? It's a pretty new build (less than 7 years), so it's unlikely to be poor insulation. Even setting the room to 20 C all the time would hardly account for such bills. This sounds like a real problem with the system, no ?

what company did you use?

sunnymeade01 · 25-04-2010 4:41pm

PLEASE HELP

hi all, I got a Thermia DUO 1550 heat pump installed in 2007

New build 4000sq ft, radiators upstairs,
my ESB usage in 2008 was 35063 units
my bills in 2008 varied from €370 - €1350(i got two bills for this amount)

my ESB usage in 2009 was 15012 units
my ESB usage in 2009 varied form €250 - €730

my first bill for 2010 was €1306 and 11264 units

this has put me in the poor house and if I get another bill like this I
will loose my house

sunnymeade01 · 25-04-2010 9:25pm

I used Heatlink

The Hurricane · 26-04-2010 11:41am

Hi Sunnymeade

Hope I can help Ive had Geothermal installed for 3 years in august this year house is 3000 sq ft built house in 2006 well insulated etc. I have an Alpha Innotech 12 kw Heat pump with boreholes as opposed to ground loops. My esb bill for last year April - April was €1470 total including light all esb house usage I used 5316 night units and 7448 day units. Last February I installed a motorosied valve at the pipe entrance to all the manifolds as there was a slight leak somewhere so the heat pump was coming on during the day when none of the room stats were calling for heat. Since I have done this and fitted a timer operating the heat pump only on nightsaver electricity 11pm -7pm. It has been great im delighted since we had the coldest winter in ages it actually worked really well. Some rooms especially with a lot of glazing just never reach the set roomstat temperature. The garage door is a wooden one wish I had put in a proper PVC sealed door ( doing it this summer) and this affects the utility which is next door to it.

Basically in the first year we moved in we got high ESB bills and I complained to the plumber he kept fobbing me off saying it was normal and the high esb bills would calm down once house dried out etc and all his customers got high winter bills I got sick of him ( hes since gone bust) and contacted Powertech to check the system out for peace of mind. His work and plumbing was perfect but he had the heatpump starting up 3 times an hour with the compressor working doing absolutely nothing which was using up units during the day and of no benefit energy or heatwise.

My advice is get the system checked out by the manufacturer and fit a timer so it only comes on during the nightsaver hours and maybe a motorosied valve depending on your system.

Your ESB usage is incredibly high either your heatpump is sized wrong for the energy demand of your house given its size or the heatpump settings are not set to come on at night when you can farm in cheap electricity.

Hope this helps you as I had those high bills for a few months and how I discovered it was monitoring the esb over a 12 and 24 hour period.

hi all, I got a Thermia DUO 1550 heat pump installed in 2007

New build 4000sq ft, radiators upstairs,
my ESB usage in 2008 was 35063 units
my bills in 2008 varied from €370 - €1350(i got two bills for this amount)

my ESB usage in 2009 was 15012 units
my ESB usage in 2009 varied form €250 - €730

my first bill for 2010 was €1306 and 11264 units

this has put me in the poor house and if I get another bill like this I
will loose my house

sunnymeade01 · 26-04-2010 12:07pm

thak's alot for the reply, I have got a timer installed for Rads and it is rarely used
also
my day units for 2008 = 17972 & night units = 17091
my day units for 2009 = 9662 & night units = 5350

I just dont understand

metalworker65 · 26-04-2010 8:12pm

I fitted a cost moniter on heating system only in order to know what going on with my system and predict/moniter bills . High bills are caused by running too much during day because heating controls not set up properly. I set mine to run flat out at night during low cost period . I have eurosmart controls which allows setting of boost heat ( induvidual zones set to plus 2 degrees during last hrs of low cost period) . This trick forces a battery storage of heat into your floor slabs in hard to heat zones which will leak out low cost heat all day and cut out expensive day units. If this is not done pump will be on during day doing work than could be done at night. My usage of electricity is in ratio of 2:1 nightsaver / day units. Pump needs to be sized big enough to do most of job during night for low cost running. Mine is a 15kw output and i wish it was bigger for cold spells.It gets allowed 4pm to 8pm during day and in cold spells it runs flat out for this period . Total heating cost year €800 year.

sunnymeade01 · 26-04-2010 10:36pm

Where can I buy a cost monitor:)

daveoc16 · 10-06-2010 6:27pm

Hi Guys,
I'm shortly starting building a bungalow approx 2500sqFt. I am trying to get info good/bad/indifferent on Air to Water HPs. In theory looks good as an alternative to Oil Boiler/Solar Panels combo.
I had planned using rads. Couple of questions end users may be able to answer....(i'm a bit clueless on this).

Is using an AWHP as good to heat the home as an oil boiler?
How effective are rads with an Air to Water Heat Pump as opposed to UFH? (much difference in the ESB bill also?)
Is installing underfloor heating much more expensive than Rads?
And finally....Of those of you that have done it, in terms of heating you home and paying the ESB bill, would you do it again??????

(I am currently looking at a brochure for a Mitsubishi Ecodan)
Any other points gratefully accepted.

Thanks in advance.

RKQ · 10-06-2010 7:45pm

daveoc16 wrote: »

Is using an AWHP as good to heat the home as an oil boiler?

Can't say as I have a borehole and ground heat pump.

daveoc16 wrote: »

How effective are rads with an Air to Water Heat Pump as opposed to UFH? (much difference in the ESB bill also?)

IMO UFH pipes are better - slab acts as a radiator & water temp doesn't need to be as high for UFH as it does for Rads.

daveoc16 wrote: »

Is installing underfloor heating much more expensive than Rads?

Yes it is.

And finally....Of those of you that have done it, in terms of heating you home and paying the ESB bill, would you do it again?????

Yes, definately.

a ken · 27-07-2010 11:39pm

Hi
building house at min does any 1 hav a well geo unit fitted . any how is it going (running costs, any trouble)
cheers al

ECO_Mental · 01-08-2010 9:17am

There are 9 pages of replys from people who have heat pumps on this tread giving their experiences of their setup's have read back through them and you will find all the answers you need

Jrochey · 24-11-2010 11:49pm

Just Wondering has anyone any info on a conenergy heat pump serie classic 13bw heat pump any good bad or indifferent stories from anyone out there thinking of gettting one any advice from anyone

mr_edge_to_you · 26-01-2011 10:16pm

Well we've reached the end of our first winter in our new house. We built a 2200sq ft house with vertical geo-thermal (Thermia) heat pump with UFH upstairs and downstairs.

It what was the coldest winter in decades we can't speak highly enough of the heating system. It was installed by a company who were previously mentioned negatively on this thread.

Our full ESB usage from October to January (4 very cold months) we are looking at a cost of €615. We're very impressed! My wife works 3 days a week so she is home most of the time. The house is lovely and warm all the time. When the winter arrived we increased the heat pump temp gradually until we reached a level that we liked. Once we got to 19 degrees we found it perfect. The installer said to take a few days and gradually increase the temp - if you lash the heatpump up to 23 degrees on the first cold day of the winter you'll need to keep it at that temp. Simple and logical - great advice.

It is also important to remember that the cost of €615 includes our standard electricity usage.

Like a previous poster, we run the heatpump through the night from 12 to 8 and that normally does the job.

How much is a fill of oil?

gunner0098 · 31-01-2011 5:22pm

Hi all,

Very interesting thread on geo and UFH. I have a NIBE 1220 with horizontal collector and UFH heating up and downstairs, in a dormer bungalow 2100 sq ft.
I have been having on going problems with my system. I want to get a 2nd opinion on my install and was wondering could anyone recommend someone they've dealt with on a professional basis to do this?

Thanks
S

galwaytt · 03-02-2011 2:14am

daveoc16 wrote: »

[*]Is installing underfloor heating much more expensive than Rads?

Tbh, in my experience, not a lot.

I say this as I am differentiating between costing a lot more and being charged a lot more, by installers.

Look at it this way, if you had a microbore system with rads, the infrastructure would be almost identical, bar the emitter (rads vs floors).

gunner0098 · 08-02-2011 1:08pm

Hi,

Can anyone tell me about the fluid that goes into a ground source horizontal collector? I know it's a mix of anti freeze and water but I'd like to know about ratio's etc.

Thanks in advance
gunner

Condenser · 11-02-2011 8:48pm

gunner0098 wrote: »

Hi,

Can anyone tell me about the fluid that goes into a ground source horizontal collector? I know it's a mix of anti freeze and water but I'd like to know about ratio's etc.

Thanks in advance
gunner

Should be around 30% glycol Gunner. You can get testers to check that the mix is ok. You should aim for a protection temp of -10 to -12. Also not all glycols are suitable for the application, so check your getting the right one, that is rated for long life.

L driver · 21-02-2011 12:45am

Hello,
Can ashp be connected to a thermal store to prevent heating the ufh at night and making the house difficult to sleep in? Then an hour or so before waking let the room stats make the call and the hp can work in the night rate again for the last hour or so on night rate. Can a hp heat a thermal store high enough efficiently.

21-02-2011 1:16am

I'm not 100% sure here but,
Yes a thermal store will work, you will need to make it larger than usual as the water will be stored at a lower temperature to allow the heat pump to work more efficiently. Normally the thermal store is set to about 65C and the water mixed down to the correct temperature. If the thermal store holds the water at the same temperature as the ufh then you'll need a tank much bigger to hold the same amount of energy.

Condenser · 21-02-2011 10:10pm

L driver wrote: »

Hello,
Can ashp be connected to a thermal store to prevent heating the ufh at night and making the house difficult to sleep in? Then an hour or so before waking let the room stats make the call and the hp can work in the night rate again for the last hour or so on night rate. Can a hp heat a thermal store high enough efficiently.

You would need a buffer of several thousand litres in order to cover the amount of energy required. Also pushing up the temp you're producing in the buffer will pull down the system efficiency so it would be counterproductive. Lastly, its normally much colder at night than it is during the day which means an ASHP would be at its least efficient, so running it like that would not give you any benefit.

If the house is well insulated and the HP designed properly you won't have to resort to such measures as the running costs would not be an issue.

L driver · 22-02-2011 1:02am

Condenser wrote: »

You would need a buffer of several thousand litres in order to cover the amount of energy required. Also pushing up the temp you're producing in the buffer will pull down the system efficiency so it would be counterproductive. Lastly, its normally much colder at night than it is during the day which means an ASHP would be at its least efficient, so running it like that would not give you any benefit.

If the house is well insulated and the HP designed properly you won't have to resort to such measures as the running costs would not be an issue.

Thanks Condenser,
I thought heatpumps had to be run on night saver? which is mad for ashp no doubt. So an ashp can be run on ordinary tariff during the day direct to the UFH and if one could pipe extract hrv and maybe a cheap ground air pipe to the ashp it should be an efficient system, can an ashp look after DHW? I have the build fabric sorted in my build now I just want to get the DHW and CH as efficient as possible, so sorry for all the Q's but I don't know much in that regard.:o

Condenser · 22-02-2011 1:09pm

L driver wrote: »

Thanks Condenser,
I thought heatpumps had to be run on night saver? which is mad for ashp no doubt. So an ashp can be run on ordinary tariff during the day direct to the UFH and if one could pipe extract hrv and maybe a cheap ground air pipe to the ashp it should be an efficient system, can an ashp look after DHW? I have the build fabric sorted in my build now I just want to get the DHW and CH as efficient as possible, so sorry for all the Q's but I don't know much in that regard.:o

Night rate is an excuse used by poor installers with poor equipment to cover their ass and appear to have lower bills. For anything under 12kw I wouldn't even bother with night rate. You don't want to heat your house when you're under a duvet, its uncomfortable and illogical.
Ground HR pipes cause restrictions in airflow so push up the electrical consumption on the fanmotor therefore decreasing COP so their benefit is questionable.
Question, why are you so sold on ASHP. There are alot of cheap units out there at the moment from some big name manufacturers but they're not all they're cracked up to be. I would exhaust all other HP possibilities before going ASHP. Especially with the winters we are told to expect in the next 5-10yrs.
HP's can more than adaquately cover hot water production but there are systems that do it far better than others. Most back up their production with immersions which is expensive, others don't require this. Its all down to product and design

L driver · 02-04-2011 9:22am

Hello,
From reading through this the installer seems to be the main problem with heat pumps going wrong? Is there any certification, proper certification for installer or is it attend a 2 day course by xxx manufacturer and pay your fee and off you go? Also is there much difference in heatpumps, could someone list say the top 5 brands with their cop when the winter is say -12 as we seem to now get and we need 20c inside and hot water, in the 8 to 12kW domestic range. Also can anyone justify a borehole over ground loop? Heinbloed puts up a decent link about a European poll, can someone from the hp side of things here stand up and give honest assessment and figures.

Condenser · 02-04-2011 2:51pm

L driver wrote: »

Hello,
From reading through this the installer seems to be the main problem with heat pumps going wrong? Is there any certification, proper certification for installer or is it attend a 2 day course by xxx manufacturer and pay your fee and off you go? Also is there much difference in heatpumps, could someone list say the top 5 brands with their cop when the winter is say -12 as we seem to now get and we need 20c inside and hot water, in the 8 to 12kW domestic range. Also can anyone justify a borehole over ground loop? Heinbloed puts up a decent link about a European poll, can someone from the hp side of things here stand up and give honest assessment and figures.

There is no real certification in Ireland. There was a SEI course that people had to attend but its not worth the paper its written on, just another money spinner for FAS training companies.
With ground source and vertical loop system, outside temp has little to no influence on their performance. Thats not the case with airsource. The COP of an air source unit will drop 3% for every degree drop in temp.
The main thing to look out for when choosing between HP's is if the manufacturer is giving credible COP's, some quote without brine circulating pumps being included in the calculation, some air source manufacturers ignore the energy required for defrost.
The European standards (EN255) are as follows :

Air source: A2 W35 (Which means an air temp of 2 and water off of 35)
Brine : B0 W35
DX : E4 W35
Water to water : W10 W35

Despite these figures looking quite different they give an almost exact match in terms of the performance outputs for each of the different types of heat pump.

You also have to look out for people undersizing machines and backing up with immersions for cold weather. Heat pumps should never be undersized by more than 10% and airsource should be oversized by at least 25%.

In order to know if you're being oversized or undersized you'll need to do a little work yourself to establish exactly what your heat requirements will roughly be.
Heatpumps under 10kw should usually add about 2kw for hot water production also.

vicar1 · 09-05-2011 7:35pm

Condenser,
You seem to know your onions, maybe you can help me? I have an old house, not well insulated ( mass concrete ) approx 2400sq. radiator system with oil and solid fuel stove in living room. Would an air to water sytem be possible or cost effective for me ? If so, any advice on manufacturers / installers ? I am in Laois.
Thank you very glad

Condenser · 10-05-2011 4:00pm

vicar1 wrote: »

Condenser,
You seem to know your onions, maybe you can help me? I have an old house, not well insulated ( mass concrete ) approx 2400sq. radiator system with oil and solid fuel stove in living room. Would an air to water sytem be possible or cost effective for me ? If so, any advice on manufacturers / installers ? I am in Laois.
Thank you very glad

I wouldn't use an air to water heat pump or any heat pump on radiators, especially in an old house. The temperature they will require will be too high and the COP on the HP will be through the floor. Add to that a diminishing output as the air temperature drops and you'll end up with a system you're not happy with.
You would need a low temp system to even contemplate using a heat pump and even then you should look at increasing your insulation first.

BryanF · 10-05-2011 6:39pm

Condenser wrote: »

I wouldn't use an air to water heat pump or any heat pump on radiators, especially in an old house. The temperature they will require will be too high and the COP on the HP will be through the floor. Add to that a diminishing output as the air temperature drops and you'll end up with a system you're not happy with.
You would need a low temp system to even contemplate using a heat pump and even then you should look at increasing your insulation first.

+1

IMHO air source heat pumps are BS, there is generally a better solution and building fabric upgrades should always come first.

bluemountainz · 12-07-2011 12:42pm

Condenser,

Maybe you could give me some advice. At the stage of self build where I need to decide on heating system and leaning towards geo with horizontal collectors. It's a new build house 2500sqft, 150mm pumped cavity, 150mm metac to slopes, 300mm fibreglass in attic, and hoping to install Siga airtight membrame to windows and doors.

Would you know roughly what size hp I would need to heat the house? Sorry if this is a really silly question, I'm a bit out of my depth and I'm getting so much advice from different hp suppliers that my head's spinning!! Any impartial advice would be appreciated.

p38dse · 20-12-2011 11:22am

For what its worth, I installed a geothermal heat pump system in my house in 2007, after a lot of messing around with settings, and finally getting night rate electric supply, I managed to get my bills down to about €150 a month, with a €200 (over the coldest period) spike last winter due to the very cold conditions.
All and all I was happy this new system was going to save me money over a ten year period...........................that was until friday when my "ultra reliable maintenance free" compressor just stopped working, called up guys who fitted the system only to be told it was unservicable and would cost €2000 to fit a new one.
Of course I paid the money, and now my heating is working fine, but, less than 5 years! Be warned this system is new to Ireland, and from my experience there are not many people qualified to recommend fitting it, as when things go wrong, it cant be repaired just replaced.
Hopefully I was just unlucky but as I was one of the earlier installs only time will tell.
Happy Christmas!

JB81 · 31-01-2012 11:58am

Hi

Just thought I would share my experience with Heat Pumps. Have an Air-to-Water Heat Pump in an 2000 sq. ft. bungalow with Underfloor Heating. Just recieved ESB Bill for the 2 months December and January ( which I understand were by no means the worst Winter ). The bill was €210. Taking into account this is for my normal ESB usage as well ( lights, TV ), and considering we had company at Christmas and a lot of cooking ( which is all electric as well ) I am very pleased with the running costs. Although I dont have a breakdown of the heating itself. It runs from 12-7am on night rate and I had it boosted for 2 hours in the evening, and this would only come on if the temperature was low enough ( which a lot if the time it wasnt ), so over all very happy with the performance.

Thanks
JB

Heat Pumps - post here.

Comments