Heat Pumps

yop

€600 sounds great for a years heating. What size house have you? I take it the €12800 doesn't include the UFH pipes inside?

What temp is the brine coming in at before the Heatpump kicks in and what temp when it has been running for a while? just for comparism

Well that is the projected so far lad. I will come back on again and keep ye updated as best I can. It will be more difficult when we start using domestic electric but at the moment it is a bit easier as we are still not living in it.

The house is 2100 sq ft. But it is a timber frame and is seriously insulated. A timber frame house requires a small KW heatpump than a block house.
Nope UFH cost me 4600 euro, but I installed it myself

We have the Direct Expansion (DX) which even though has people sceptical will return a higher COP with a smaller loop coverage.

alfa wrote:

Yop,

Would you mind advising on who carried out your installation and the type of installation i.e. bore hole or other.

Apologies if I am asking questions which you have answered previously as the search function is currently disabled and I am looking to get a number of quotes in the next few weeks.

Thanks again

Alfa

No problem Alfa, a company called Climate Control is who I used. For 3 reasons, one is because they were local enough, so that if an issue arose they could come and sort it.
2 - The had a DX system which I wanted.
3- Their system is very neat, has an outside air sensor to tell the HP to adjust and they were talking to me in plain English.

It is a loop system. Bore hole from what I hear is the best option available as regards it COP but would cost more to setup, same heatpump but the drilling costs.

alfa

yop wrote:

Ours in not running mad long but the electrical cost of running the heatpump is 1.66kw per hour. The pump is a 12kw Heliotherm in a timber frame with UFH installed to run at 35 degrees instead of the "normal" 45 degrees.
Based on Feb, March, April we are looking at a running cost of in or abouts 600 euro per year for the heating and hot water.
In saying that for the hot days last week Wed & Thursday it did not come on at all as the house temp was sufficent. So I do expect the heating cost to decrease for the summer months therefore bringing down the 600 euro costs.

We have ours also on Night rate with a 500l tank. Ours does come on in the evening again from 7-9pm to boost the house.
The advantage with ours I think would be that there is an outside temp gauge linked to the HP so that it can adjust the temp required in the house based on temp outside.
Still learning how exactly to use it but give it 12 months and we will have a full idea.
Installation and HP cost was 12800 euro, digger and sand 1k euro.

Yop,

Would mind advising on the type of installation and who carried out the install.

I am looking to change over from oil boiler as cost is astonmical with u/f.

I have been following your comments on the site for a while and apologise if you have already provided details of install and supplier but have been away from site for a while and the search function is disabled once again.

Thanks

Alfa

iplogger1

Alfa - I've sent you a PM. I'm planning on going down the
GS/heat pump route for underfloor heating on a 2700sq ft (250m^2)
two storey house. I'm wondering what your annual costings are
for UFH with oil. The GSHP folks gave me a guideline as to what
an oil boiler source would cost and I want to confirm whether
they have exaggerated the projected oil costs (which I doubt
but would always keep an open mind on).

~ipl

Ayla

Hey all, great posts recently. It's really helpful seeing the running costs from people who actually have the systems.

I'm wondering if anyone out there has an aerothermal system?

I've heard varying reports as to whether the aero or GS heat pumps are more efficient and it'd be good to see the varying costs, etc. of aero now that we have some GS costs to compare by.

yop

Okily - on the oil, my mate has a 2500 sq foot block house with UFH. Their oil bill is running at plus 3k euro per year. They would have a lot of passive heat as they have glass along one wall of the house.

Aerothermal is supposidly the least efficent of the alternative energies. The issue with ASHP (air source heat pumps) is that when u need heat the most there is the least amount of heat in the air. You will then be compensated with you immersion to heat your house. Also there are "defrosters" on the fans to clear the ice build up before they spin, this too is based on a immersion. All costing electricity.

I have a mate who put them in, the had to over size the heatpumps to try and compensate.
His electric bill is working out about 1200 euro alone for the heating costs. On top of the 12k euro he paid for the system.
IF you can go with a bore hole, or groundsource, or water sourced system then air is all that is left

tomoose

hi all,
just read the thread and found it very helpful. will start building my own house next year and have decided to go for as passive a house as i can get using ICF (insulated concrete forms). was going to go down the road of UF but have decided against it. will use natural stone carpets (naturalstonecarpets.ie) as they are warm and i like the massaging effect they have on bare feet.

anyways while trawling the net found this product which is meant to improve the performance of UF. check it out at http://www.oxyvent.com/. i havent any experience of it myself so cant rate it but the blurp sounds good.

this might help some of those suffering from high UF bills.

air

tomoose wrote:

anyways while trawling the net found this product which is meant to improve the performance of UF. check it out at http://www.oxyvent.com/. i havent any experience of it myself so cant rate it but the blurp sounds good.

this might help some of those suffering from high UF bills.

OK, this oxyvent thing has been around for a few years and I know nothing about it. However I've just had a quick look over the website and my thinking is this:

Say you have a modern condensing gas boiler that is 97% efficient (not unreasonable) and you plumb it into your central heating system.
This guy claims that this device can reduce your heating bills by 30% and IMO this must come through increased efficiency.
Now as I understand it from my brief reading of the website they seem to claim that the device improves the heat transfer between the central heating system and the ciruculation water. Now this isnt unreasonalbe, however in my opinion if the device works as it claims it could lead to increased peak output from your boiler, but it would not increase the efficiency of your heating system as a whole at all.

Look at it this way, say your boiler is 100% efficient at converting gas energy into heat in the water that passes through it (a simplification but modern boilers are close to 100%).
Now this site claims that the device increases efficiency by 30%?
Where is that 30% of your energy being lost?
Its not being lost in the boiler because it's 100% efficient, so where is the loss?

If I'm to try and make excuses for the product, I would argue that perhaps oxygenation of the circulation water reduces the peak heat transfer capacity of a unit of water by 30%. By employing this device, the heat transfer is improved and you can get more heat output from your boiler.
However, you will also burn more fuel as a result!

To be honest I dont see this thing as any kind of a magic bullet for heating systems. If oxygenation in your circulation water is restricting your heat output I dont see why this couldnt be overcome by increasing flow rate by 30% instead of fitting this.

I cant comment on the other stuff the site mentions on optomising UFH system.

boomshackala

air wrote:

Look at it this way, say your boiler is 100% efficient at converting gas energy into heat in the water that passes through it (a simplification but modern boilers are close to 100%).
Now this site claims that the device increases efficiency by 30%?
Where is that 30% of your energy being lost?
Its not being lost in the boiler because it's 100% efficient, so where is the loss?

Ha! a common misconception. Your boiler runs 97% efficient under TEST conditions WHEN operating with condensing mode.

Your overall system efficiency will be down at 50-70% though, as the boiler takes time to heat itself when igniting, as well as the water store.

If you run on a thermostat I would imagine this makes it worse as the boiler is constantly kicking in and out. turning on say twice day would'nt be so bad.

air

I never said that system efficiency was 100%, my point was that poor heat transfer in the heat exchanger of the boiler would should not cause a major reduction in efficiency (where is the heat being lost to?).
I dont have any experience on the actual efficiency of boilers in the real world I'm just going on published figures.
What is your point in any case?
I dont think that time taken to heat the water store is a source of inefficiency, it is after all a transfer of energy from the gas / oil etc to the water you want to heat.
Also assuming your boiler is indoors, the heat used to heat the boiler itself will be returned to the ambient air anyway so this is not a source of efficiency loss either.

riccol1966

another option, which I wonder if anyone has experience with, is running heat pumps with SOLO radiators. I was looking at the specs for this (www.lowenergy.ie) and wondering if, because of the reduced water requirements, would this mean lower heat pump running costs?

Ahhh, just realised that these special rads use 60W power each, so not sure if you have 10 of these running 10 hrs per day whether that would eat into the original savings made on the heat pump electricity?

Be great to hear from anyone using SOLO?

funcrusher

Sorry folks it has taken me so long to get round to a second post. I've been busy educating the masses on the green building forum.

The important considerations in a heating system are (1) the heat generator (2) the heat distribution system (3) the style of social use and (4) the climate (5) the insulation levels and (6) the thermal mass.

In essence, the thermal mass, insulation and social use will determine the required heating profile and you then design a heat generation and distribution system to meet this.

Most of joe public do not understand that the Laws of Thermodynamics dictate that all heat is not equal. If you heat 10 litres of water by 50C it requires as much heat as 100 litres heated 5C. BUT heat at a higher temperature is capable of producing more work in a heat engine (eg a steam engine) than heat at low temperature. The reverse is also true. MUCH more energy gets wasted trying to heat a 10 litres by 50C than 100L by 5C.

So....a condensing boiler (or any other boiler) is likely to be most efficient when designed to heat luke warm water rather than hot water.

Now 'green politics' has propelled ignorant governments to insist on more 'efficient' boilers etc. The result is cheaper, lower temperature heat, which is then wasted in UFH because there is no other practical way of distributing it.

The problem is that if you use low temperature water in a CH system, you need giant radiators, because the efficiency of radiators in dispersing heat into the room increases dramatically with water temperature. Similarly, With a high water temperature you will get a quicker respoonse when you switch on, partly becuase the water content of the system is much lower so it heats more quickly, as well as radiating faster.

To avoid giant radiators, UFH has been promoted. Now UFH is effectively a high thermal mass concrete storage radiator. In fact if you run you UFH on off-peak electricity (whetherr via a heat pump or direct electrical heating), it is for all intents and purposes simply a very expensive night-storage heater. It suffers from all the disadvantages of night storage heaters: wasted heat at night, lack of control, poor response, impossibility of co-ordinating heating with climate.

I should say at this point that I am assuming that the household is not in residence 24/7. Places like nursing homes need 24/7 heat, and then UFH is efficient.

Heat pumps are in principle a good idea. For one thing, especially if coupled with off-peak use, they allow energy to be converted into electricity in highly efficient power stations, wind turbines or whatever is best, and that electricity sent by wire anyplace, and then reconverted back into heat with a COP of about 4 to release a similar amount of energy as was used in the power station.

But the Laws of Thermodynamics say they will be most efficient with a relatively low output temperature - too low for a CH rad system. They can be used in UFH, but that really amounts to using cheap heat wastefully, which defeats both green objectives and your bank balance.

The way to match requirements is to use a forced warm air system, as is common in America. Warm air heating uses heat at relatively low temperatures, matching the output of the heat pump. Furthermore, it gives great response and control. hEnce little or no waste. It even brings the possibility of air conditioning/humidity control.

The drawback is that (like UFH) it must be catered for at the design stage because it is difficult to retro-fit.

Heat pumps are capital intensive. Furthermore, to run on off-peak electricity you need some form of heat storage system: not an uncontrollable concrete UFH store, but a large insulated tank of water. This is pumped as necessary through a water-to-air heat exchanger to provide fan-driven warm air through your heating ducts. You switch it on and off like a CH system, and it is topped up every night.

You need to optimise the kit of parts (heat pump, heat storage tanks etc) to optimise the overall cost on an investment basis (ie taking into account fuel consumption, interest charges, depreciation and maintenance). The optimum will probably incorporate a peak-lopping strategy. By that, I mean that in our variable climate, it is not likely to be economic to buy vast kit just to cater for a few very cold days. Better to buy smaller kit and to meet these peak requirements by eg peak rate immersion heaters or heat pump use, rather than bigger kit lying idle most of the time.

Finally, if you do advanced heating calculations, you will find that for a house insulated to current standards, the greatest heat loss is through air change/leakage. If you go for an Ametrican style warm-air system, a by-product is that you will also need to address air-flow and leakage with a big saving on heat losses.

CJhaughey

funcrusher wrote:

The drawback is that (like UFH) it must be catered for at the design stage because it is difficult to retro-fit.
I don't think this is strictly true, if you look at the nordic countries a common use of heatpump technology is the air-to-air style heatpump which can be fitted to any house in half a day.

Heat pumps are capital intensive.

Again I refer you to the air to air heatpumps which can be bought and installed for €2000 here in Rip off Ireland, I think that is a pretty reasonable price for heating option.
My solid fuel stove plus flue cost around €2000 and is not half as convenient or efficient as a A-A heatpump.

riccol1966

2000! I'll take 5 then. I take it you meant 20,000. And change.

CJhaughey

No I mean two thousand euro fitted.Look at the www.scanhome.ie website.
Thats what I can't understand why would someone go to all the expense, hassle , garden destruction to fit a ground source heat pump for 20 thousand.
and then have to pay for a 6-10 kw pump to run it?
makes absolutely no sense to me.
And with the Panasonic heatpumps you can also run them in reverse in the summer to cool your house, I would like to see that work with a GSHP.

funcrusher

CJ Haughey:

If I understand you comments correctly, you are either wrong or have misunderstood mine.

A forced warm air system requires ducting, and the positioning of supply/return outlets is critical. It is extremely difficult to retro-fit satisfactorily. That is why high velocity mini-duct systems are now being promoted, but there are technical drawbacks(I will spare details)

Your figures on heat pump energy consumption are simply wrong. The heat pump will typically consume a max of 2 or 3kW. The circulating pump will consume far less, about 200W max I should think.

It is perfectly possible to use air-to-air heat pumps. They are popular because they are cheaper to install and require no garden space. However, they are less efficient because whereas ground temperature is not much affected by cold winters, air temperature plummets on the very days you want max heat. The second Law of Thermodynamics rules, Ok? The fans are also a source of noise.

CJhaughey

Funcrusher
I am in agreement with you as regards forced warm air, I have a HRV unit in my house and I find it excellent but as you say all the ductwork has to be planned and allowed for at design and construction stage.

Point taken on GSHP draws but I have heard of people having huge pumps fitted, if the search function on this site functioned you could actually see old threads where the size of pump I mentioned was installed.

regarding Air to Air heatpumps they may be less efficient but only at temperatures below minus 25 deg C
This almost never occurs here in Ireland and actual average temps are 9-10 deg.
These units are very widely used in Sweden which has a considerably colder climate than here, if they are so inefficient why are they popular in a colder climate?
The COP of most of these units is at least 3.81 and rises to over 5, that is for every 1 unit of electricity you put in you get 3.8-5 back.
The other advantage is that you can run them in a cooling capacity in the summer
The fans are a source of noise however there are few complaints about fridges being too noisy and at 29db I am sure most people could live with the noise while enjoying the heat.

funcrusher

I spoke to Ola, the old Swede who runs SWECO in Ireland about all this. The reasons that air sourced heat pumps are used widely in Sweden are often much the same as Ireland: lack of ground space and capital cost. Icing up of the ground is also more of a hazard in Sweden for GSHP. He agreed with me that a water-sourced pump is by far the most efficient, but it is very rare to find an ideal water source in the vicinity, particularly one free from debris and alien activity which can wreck the heat exchangers etc.

The second law of Thermodynamics determines that in theory the efficiency drops with falling source temperature. The problem with air-sourced is that we are looking for greatest output when air temperatures are lowest. On the other hand, ground source tends to have a nearly constant source temperature. Apart from anything else, that means that in order to meat max demand (cold days) you will need a much larger ASHP than GSHP. Obviously other practical factors influence choice: an air site is almost always available, a ground site less frequently, a water source rarely. In addition, installation cost vary.

abakan

Evergreen wrote:

Hello,

This is a very interesting discussion.

If anybody is interested in doing a heat load calculation on their house then let me know, I have an Excel program that I use everyday for determining the size of heating requirements a house will need. It takes in all elements of the house, i.e. wall type, numbers and type of windows/doors, ceiling insulation, etc.

hi do you still have that excel doc going??

sarahirl

Qwerty? wrote:

Here's some facts for a 2 story block house, open plan downstairs, UFH on both floors, 3500 sq foot and includes tank of hot water 24/7. The house is well insulated. No supplimentary heating system used.

I've geothermal in since December, and got my electrician to put a meter on it in January, so I can have an accurate reading of it's use.

For the last 24hrs it has cost exactly €1.80 (not counting Nightsaver - which would bring it down to about €1.50.
On the 3rd of March, when the ground was covered in snow, and the outside temp was -7 it cost €5.95.


Heres the daily Average for Feb to May so far:-

February €4.53
March €4.10
April €4.33
May €2.50
(again none of these figures include nightsaver - subtract approx 1/4 to get an approx value.)


Call back next Feb. for a yearly costings...:) which I'm hoping to be €1000 or less, which I think is a reasonable price for heating and hot water for this house.

Hi, Have you got your yearly costings - would be really interested to see them. Also, was just wondering from a non-technical view, how large a space do you need to house the heat pump, buffer tank, etc. I've heard talk of a car parking space needed. Also, is it noisy - another common comment on these systems. Also, the UFH - how do you find that. I honestly can see nothing positive written on that system in this thread. The only plus I can think of myself is that some people do not like the look of radiators and UFH is more discreet. And of course the nightmare stories of improper installation and having to get the whole floors ripped up....

Appreciate any info!

Qwerty?

sarahirl wrote:

Hi, Have you got your yearly costings - would be really interested to see them.

Hi Sarah, heres the figures, excluding Nightsaver savings.
2006
February 4.53
March 4.02
April 4.10
May 2.67
June 1.23
July 1.01
August 1.42
September 1.53
October 2.42
November 4.06
December 4.35

2007
January 4.55
February 5.06
March 4.39
April 3.12

sarahirl wrote:

Also, was just wondering from a non-technical view, how large a space do you need to house the heat pump, buffer tank, etc. I've heard talk of a car parking space needed.

We have a room in the middle of the house 2m wide * 1.6m deep, you need the 2m wide (if you use the separate HWC), but about 1m deep is more than adequate if your door opens out.

sarahirl wrote:

Also, is it noisy - another common comment on these systems.

Honestly... nope. We hadn't a door on the UFH room for weeks, you could hear it then, but it wasn't bad. When the door is shut, you can't hear it over the normal noise in the house.

sarahirl wrote:

Also, the UFH - how do you find that. I honestly can see nothing positive written on that system in this thread. The only plus I can think of myself is that some people do not like the look of radiators and UFH is more discreet. And of course the nightmare stories of improper installation and having to get the whole floors ripped up....

Love the UFH, would never have radiators in a house again, warm floors and no cold spots.

sarahirl

Thank you very much! You've cleared the few questions I had about the system.

aquadec

Qwerty? wrote:

Hi Sarah, heres the figures, excluding Nightsaver savings.
2006
February 4.53
March 4.02
April 4.10
May 2.67
June 1.23
July 1.01
August 1.42
September 1.53
October 2.42
November 4.06
December 4.35

2007
January 4.55
February 5.06
March 4.39
April 3.12



We have a room in the middle of the house 2m wide * 1.6m deep, you need the 2m wide (if you use the separate HWC), but about 1m deep is more than adequate if your door opens out.



Honestly... nope. We hadn't a door on the UFH room for weeks, you could hear it then, but it wasn't bad. When the door is shut, you can't hear it over the normal noise in the house.



Love the UFH, would never have radiators in a house again, warm floors and no cold spots.

Hi,

Im in the process of building a 2700 sq f house, have UFH down and up stairs, and Im looking into a few suppliers, eco heat and IVT are two. Can anyone point me in the right direction or have had any experience with suppliers. Who did you use.

wazzoraybelle

Just a quick question on above, I have 2 wells on my property. Neither are very good but one just about covers our day to day needs. the other( which is about 150 metres from the house) is pretty bad but as we don't use it for anything is always full. Would it be possible to use this one as a vertical bore for a heat pump? or Would it need to be able to replenish itself quickly or is it too far from the house??
Thanks.

wazzoraybelle

anyone?

wazzoraybelle

wazzoraybelle wrote: »

Just a quick question on above, I have 2 wells on my property. Neither are very good but one just about covers our day to day needs. the other( which is about 150 metres from the house) is pretty bad but as we don't use it for anything is always full. Would it be possible to use this one as a vertical bore for a heat pump? or Would it need to be able to replenish itself quickly or is it too far from the house??
Thanks.

I dont think that the distance would be too much of an issue, the flow from the well might, assuming you have an open loop system (extract water, pass it through the heat pump then discard the water) I would imagine that an installer would prefer to install a closed loop system and sink a new borehole rather than try to use an old well .

wazzoraybelle

Thanks

liberty 2007

Hi
I'm wondering, has any consideration been given to or study been carried out on the store of heat in the ground and if and when it would be exausted. ie. does the pump have to work harder in march then in december?

liberty 2007

liberty 2007 wrote: »

Hi
I'm wondering, has any consideration been given to or study been carried out on the store of heat in the ground and if and when it would be exausted. ie. does the pump have to work harder in march then in december?

I imagine it would, but I have no firm figures, unless the system uses deep bore collectors into an aquifa.

lelah49

Hi there, I am just putting the finishing touches to my house that I built in a rural are and I have put in both a heat pump and a solar panel. I am not living in the house but for th last two months the pump has been working to dry out the house and keep it from getting damp. it is currently at between 15-19 ( I've kept the temp low as dont need it any higher) degrees and has cost me about 70 euros over the two months. I am now increasing the heat which will take a bit and will let you know the actual cost of it as like your family I was very uuncertain about installing one - my father is in construction and he was very unsure but he seems to be coming around. will keep you posted

Ragazza wrote: »

Hello, I am looking for a person living in a new house with a heat pump system installed. or someone who knows someone. I am designing a house for my parents. They are a bit dubious about the Heat Pump. My brothers insist you can't go wrong with oil, and think the heat pump is a con and you will never make your money back.:mad: (They are not construction professionals and as I am a girl, what would I know.:mad: :mad: :mad: I am an Architectural Technition)
We are building this house for my parents to retire to, they will not have much of an income and I believe spend once now rather than over and over again in the future.

Mum and Dad want to hear from the horses mouth that this system works.:)

liamolaighin

lelah49 wrote: »

Hi there, I am just putting the finishing touches to my house that I built in a rural are and I have put in both a heat pump and a solar panel. I am not living in the house but for th last two months the pump has been working to dry out the house and keep it from getting damp. it is currently at between 15-19 ( I've kept the temp low as dont need it any higher) degrees and has cost me about 70 euros over the two months. I am now increasing the heat which will take a bit and will let you know the actual cost of it as like your family I was very uuncertain about installing one - my father is in construction and he was very unsure but he seems to be coming around. will keep you posted

Hi there I was wondering if you have gotten any running cost figure at this stage for your geothermal. I notice you posted around a year ago and was wondering how it has been going since as I'm thinking about going with geothermal myself now on a 3,200 sq/ft new build?

What kind of insulation did you use in walls and roof?

Did you use any airtight membranes or tapes etc?

Are you happy with your system and do you have an idea how much it costs to run per year?

doncon

Hi Evergreen, do you still have that excell sheet, could you pm it to me please