Heat pumps Infomation

AckwelFoley

There are 3 types being used in Ireland today.

Vertical Borehole (water) heat-pump

Horizontal (groundsource) heat-pump

Air-source heat pump


For climates like Ireland, with moderate heating and cooling needs, heat pumps can offer an energy-efficient alternative to furnaces and air conditioners. Like your refrigerator, heat pumps use electricity to move heat from a relatively warm space to a cooler space.
Heat-pumps are used for heating hot water that is used for water and space-heating. The system takes advantage of clever technology but in terms of capital costs is one of the most expensive renewable energy technologies currently on the market.There are 3 common types of heatpumps. They are rated in order of efficiency below

• Vertical heat-pump
• Horizontal heat-pump
• Air-source

On average, the first will deliver approximately 5kW of heat energy for every 1kW of electricity.

A ground source heatpump will deliver about 4kW of heat for every 1kW of electricity.

While an airsource heatpump will provide 3kW for every 1kW.

This obviously has a bearing on the payback time for the investment. The capital cost of the equipment should be weighed up against the savings being made on space heating.

In order to calculate your savings, you should find out what your house or a house similar in size to yours, uses each year in heating energy costs. In a recent document the Irish government’s renewable body SEI provide the example of a 120m² house using 27,456 kWh of energy per annum for space heating, costing €985 per annum on heating oil. If heating oil costs 60c per litre, this equates to 1597 litres of oil per annum.

With a heat pump, you would pay for ¼ of this 27,456kWh of this heat energy. This means you would pay for 6864kWh of electricity. Night saver rate is 7.05c per kWh while day rate is 14.35c per kWh. It is therefore very important that night saver rate is chosen by somebody using a heatpump. On night rates the heatpump for this house would cost €480 euro per annum, at present rates.

So, to use the SEI’s 120m² example, you would save €505 per annum on space heating. The minimum time it will take to pay back this cost is the cost of installation divided by the savings.

A heat pump is technically very similar to a refrigerator in the way it operates except that a heat pump is usually used for heating rather than cooling. In other words, when used for heating, a heat pump operates like a refrigerator in reverse.

In a domestic fridge, heat is “pumped” from an evaporator inside the refrigerated compartment to a condenser (see photo on right) on the back of the refrigerator. Thus lowering the temperature of the refrigerator and warming the kitchen. The condenser on the back of a fridge is a familiar shape to many people, consisting of an “S” shaped pipe with a grill.

In a heat pump, the evaporator is located somewhere in the external environment or outdoors. Heat is then pumped from the outdoor source to a condensor inside the building which is warmed as a result. The condensor then gives its heat to the heating system in the house. As a result of taking the heat from the outdoor environment, the area around the evaporator can be cooled by an appreciable degree.

The heat pump process is made possible by a special refrigerant liquid that boils at low temperature.

Mothman

snyper wrote: »

On night rates the heatpump for this house would cost €48 euro per annum, at present rates.

Out by a factor of 10.
6864kWh of electricity at 7.05c per kWh = €480

And I don't understand

So, to use the SEI’s 120m² example, you would save €985 per annum on space heating. The minimum time it will take to pay back this cost is the cost of installation divided by the savings.

the figure of €985 was used earlier as being the cost using oil, so it can't be a saving unless the replacement energy source costs nothing.

AckwelFoley

Mothman wrote: »

Out by a factor of 10.
6864kWh of electricity at 7.05c per kWh = €480

And I don't understand
the figure of €985 was used earlier as being the cost using oil, so it can't be a saving unless the replacement energy source costs nothing.

Correct Typo on the factor 10.

On the second point the savings would be 505 per year,and yes noy calculated on the 985 the difference between the cost of oil and the running of the Heat pump at the 6o cent is only an exmple, it closer to 70 cent now i think?

ardara1

SOrry folks - just transfered this from an earlier post

---

I hear the AECB in UK have called for GROUND SOURCE HEAT PUMPS to lose their 'renewable' label and to stop any grant aids for their installation.
(Association of Environmentally Conscious Builders - or the Sustainable Building Association)

'Widespread COPs of less than 2.0 - people installing a system that cost 3 or 4 times the cost and emits more CO2 than the gas boiler it replaces'

Not encouraging!

smooth operater

I wonder if air to water heat pumps will still be keeping their label?

sydthebeat

If you could get them to run for renewable electricity (photovoltic / wind etc) then i could see no reason they shouldnt be the market leaders.

Their biggest problem at the moment is that they are run from a very inefficient electricity grid (probably about a COP factor of 2.8 - 3.0 in some case).... so although they themselves have a COP factor of 3.0, in order to run them power stations running at a factor of 3kw/h energy in only produces 1 kw/h energy out, plus the inevitable co2 emmissions.

Mellor

ardara1 wrote: »

'Widespread COPs of less than 2.0 - people installing a system that cost 3 or 4 times the cost and emits more CO2 than the gas boiler it replaces'
!

I've been saying that since the start.
As syd pointed out, Heatpumps are not good for the environment, due to current grid set up. They have got great potential however.

Sealrock

Any help appreciated..

Originally, I had wanted geothermal and ufh, however, the house I'm currently looking at buying is a builders finish house, which has an oil boiler and radiators already installed.

I have noticed reference to Air Source Heat pumps, which apparently can be connected to the existing radiators. Is this true and does it work?

Thanks

Sealrock

sydthebeat

Sealrock wrote: »

Any help appreciated..

Originally, I had wanted geothermal and ufh, however, the house I'm currently looking at buying is a builders finish house, which has an oil boiler and radiators already installed.

I have noticed reference to Air Source Heat pumps, which apparently can be connected to the existing radiators. Is this true and does it work?

Thanks

Sealrock

heat pumps suit UFh becaus eboth are efficient at lower temps. UFH works at about 55deg whereas rads work at about 70deg.
Heat pumps would have to work inefficiently to get temps up to 70deg. remember that they are working from th egrid so you are paying running costs on top of installation costs that would makewhat you are enquiring about uneconomical IMHO.

If you have the room id think about a wood pellet burner...

Sealrock

Sydtherock

Thanks, I should be able to put a wood pellet boiler in, would it be better to supplement or replace the existing boiler.

One thing with ufh, I was thinking of putting them under a stone carpet, not sure if that would work, concrete floors are in.

(By the way, sorry for crashing the thread)

Cheers

Sealrock

sydthebeat

Sealrock wrote: »

Sydtherock

Thanks, I should be able to put a wood pellet boiler in, would it be better to supplement or replace the existing boiler.

One thing with ufh, I was thinking of putting them under a stone carpet, not sure if that would work, concrete floors are in.

(By the way, sorry for crashing the thread)

Cheers

Sealrock

In theory stone carpet would work quite well with UFH, but ive no idea how the sealant on the stone carpet reacts to heat.... as ever, contact specialists.

bauderline

As this is the heat pumps information thread I am putting this link in here as well.

http://www.kensaengineering.com/pdf/faq/Fact_Sheet_-_Power_Supplies_For_Kensa_Compact_Heat_Pumps.pdf

Best regards, Baud.

ircoha

I was in Berlin last week and dropped in on this gig.

http://www.eurosolar.de/en/index.php?option=com_content&task=view&id=287&Itemid=83

I took the opportunity to raise, by way of a question from the floor, in the presence of 400 delegates, the issue of actual performance of heat pumps in Ireland with one of the head honchos from the German Heat Pumps association who had just made a presentation on heat-pumps.

I had in mind my own experience thereof as well as reading a lot of the pain here.
The discussion was very lively as some of the other delegates got stuck in as well.

In the end he gave me a commitment, in public, that he will provide whatever technical advice/help he can in trying to identify the cause of problems and then suggest solutions.

Therefore, I would be interested in collating as much data as possible on how heat pumps are performing with a view to taking up the matter with him.

Please provide as much detail as possible, by way of model number and a web link if possible.

The project spec should also be provided, ie expected heat demand and delivery thereof [hot water, ufh, rads, fan coils etc], the length, depth and orientation of any underground loops: the fluid used in the pumps etc.

I appreciate the issues of esb pricing etc but in simple terms if the installer promises a COP of 5 and the result is 2 then we need some answers.

My only interest in this is to see if we can bring some order and reliability into the heat-pump sector.

Thanks
I am also interested in success stories so as we can build on them.

Chimpster

Good work Irocha,

As part of some BER assesments I am doing I have had to get some Independent Test results sent to me by a few suppliers, these tests were done by D-A-CH in Swiz/Germany.

These results would have a COP of between 4 and 5 for most ground source heat pumps.

They majority of stories I've heard are quite good to be honest, though I question the whole 'payback' on these systems myself.

I assume getting the basics right will help out some niggling issues...

- Proper sizing of system
- max use of nightrate tariff
- Home insulated to required level
- Suitable flooring on UFH
- Good control system with properly wired stats :rolleyes: (Personal issue)
- Good Air Tightness

The biggest problem with heatpumps is that our electricty is produced at very low effeciencys. There fore the COP gain you get with the heat pump is lost in the CO2 calculation.

If a heatpump could be powered from renewables...

Then your talking!

KAGY

sydthebeat wrote: »

If you could get them to run for renewable electricity (photovoltic / wind etc) then i could see no reason they shouldnt be the market leaders.

Out of interest, how big would would the turbine (diameter) have to be to provide the 3-4kW operation and the high current draw at compressor start up?

smooth operater

What size heat pump?
A 6kW turbine is 5.5m in diameter

Foleyart

I think one of the things no one is mentioning is the actual wattage of the heat pumps. We built recently and I had been very interested in geo-thermal until I discovered the size of the pumps. For a large house you a talking about a 14KW pump.The heaviest draw in most houses is an electric kettle which is about 1KW. Just to put it in perspective. As I am also interested in installing a wind Turbine on my site at some stage, I realised that unless I was to put in a commercial turbine it would be redundant. A 5KW turbine would be as big as I could put in. When I was researching the heating project I could not come across mention of the wattage of the heat pump anywhere, even when I asked a supplier at an ideal homes exhibition in Galway, I found it out by pure chance. We went with wood pellet and although we did have some teething problems at the start, it is now working very well for the last year. I am looking at the skystream turbine at the moment ( mentioned on another thread here) and it looks a good possibility, barring a question on braking in high winds.

smooth operater

Foleyart wrote: »

I think one of the things no one is mentioning is the actual wattage of the heat pumps. We built recently and I had been very interested in geo-thermal until I discovered the size of the pumps. For a large house you a talking about a 14KW pump.The heaviest draw in most houses is an electric kettle which is about 1KW. Just to put it in perspective. As I am also interested in installing a wind Turbine on my site at some stage, I realised that unless I was to put in a commercial turbine it would be redundant. A 5KW turbine would be as big as I could put in. When I was researching the heating project I could not come across mention of the wattage of the heat pump anywhere, even when I asked a supplier at an ideal homes exhibition in Galway, I found it out by pure chance. We went with wood pellet and although we did have some teething problems at the start, it is now working very well for the last year. I am looking at the skystream turbine at the moment ( mentioned on another thread here) and it looks a good possibility, barring a question on braking in high winds.

So instead of buying the 14kW heat pump you went and bought the 14kW wood pellet boiler?

KAGY

Foleyart wrote: »

For a large house you a talking about a 14KW pump..

Be careful here, there are two wattages for each heat pump, the power draw, and the heat output. For a house of about 200m2 you would be looking at about a 14kW heating requirement. A heat pump will take roughly 2/3 of this from the ground, with the extra 1/3 being the electricity used to run the compressor (massive simplifications here!) So your heat pump would be electrically rated at about 4-5kW

Foleyart

smooth operater wrote: »

So instead of buying the 14kW heat pump you went and bought the 14kW wood pellet boiler?

That misses the point nicely! You are talking heat output and I am talking electrical wattage. A friend of mine put in a heat pump and although initially a fan has since discovered the horror of escalating esb bills. He is also looking into the possibility of alternative power source and although he has a stream I would kill for running right in front of his house, which could easily take a 3kw water turbine, it wouldnt even tickle his heat pump.

KAGY

Sealrock wrote: »

Any help appreciated..

Originally, I had wanted geothermal and ufh, however, the house I'm currently looking at buying is a builders finish house, which has an oil boiler and radiators already installed.

I have noticed reference to Air Source Heat pumps, which apparently can be connected to the existing radiators. Is this true and does it work?

Thanks

Sealrock

To be honest, I wouldn't recommend them. They aren't as efficient as ground source and can be subject to frosting up in our damp climate. I can't see the reason for going with an air source over a ground source, as the temperatures from both are similar. The only difference is that you will need to drill or dig your garden.

You are looking at a water temp of around 40deg from both, (you can force it higher, but it's less efficient then). Your major problem is then that the rads are probably sized to have a working temp of 65deg so mightn't be large enough to heat the room quickly.


Afterthough: maybe you could use a heat pump (air or gnd source) to preheat the water and then use the oil boiler to boost it up to 65deg. AFter all you have already paid for the boiler

smooth operater

Foleyart wrote: »

That misses the point nicely! You are talking heat output and I am talking electrical wattage. A friend of mine put in a heat pump and although initially a fan has since discovered the horror of escalating esb bills. He is also looking into the possibility of alternative power source and although he has a stream I would kill for running right in front of his house, which could easily take a 3kw water turbine, it wouldnt even tickle his heat pump.

your friend has this 14kW heat pump-geothermal yes?
he wants 5000watts of heat, he'll put in 1250watts of electricity?
no?

wheras if he wanted 5000watts of heat from a gas boiler he'd have to burn 5495watts of gas (whatever that is in m3)

AckwelFoley

KAGY wrote: »

To be honest, I wouldn't recommend them. They aren't as efficient as ground source and can be subject to frosting up in our damp climate. I can't see the reason for going with an air source over a ground source, as the temperatures from both are similar. The only difference is that you will need to drill or dig your garden.

You are looking at a water temp of around 40deg from both, (you can force it higher, but it's less efficient then). Your major problem is then that the rads are probably sized to have a working temp of 65deg so mightn't be large enough to heat the room quickly.


Afterthough: maybe you could use a heat pump (air or gnd source) to preheat the water and then use the oil boiler to boost it up to 65deg. AFter all you have already paid for the boiler

There are a few inaccurcies in your post there.

There is a Daiken heat pump on the market that uses refrigrant coolant fluid tec that has been proven to be comparable to ground source.

There are also, air source heat pumps that have the ability to monitor the temp and will heat them selves automatically to prevent freezing up.

Armed with the above information the "difference" in cost for the ground source is in the 1000's. I know 1 gent that paid 38k for a vertical installation ex the heat pump!

They can comfortabley reach high temps, such as 65 degrees, Heat loss and exterior temp effect the performance, not the water temp. To say less efficent is true, but compared to the price of running the alternatives such as oil, its still alot cheaper.

Rads are unsuitable for heatpumps, unless they are alu rads or fan assisted rads, or in some situations when incorporating an existing build with a new build cast iron rads can suit because of their larger size, but still not ideal - therefore requiring higher energy

Ordinary rads are operated off a temp of 60 degree water, but the water that is circulated in the under floor is generally going out at an average of 28 and returning at 21, but never gigher than 35.

KAGY

snyper wrote: »

There are a few inaccurcies in your post there.

There is a Daiken heat pump on the market that uses refrigerant coolant fluid tec that has been proven to be comparable to ground source.

I'll admit that I haven't been keeping up with the latest commercial offering. I'm about 7 years behind Still one advantage of ground loop over air is that the ground temp is more stable, running a air source at night to take advantage of cheap elec would mean you are working with an increased temp diff because of the cold air. However, I suppose that the reverse is true, using it during the day you would have a reduced temp diff. Maybe that's how they can get the 60deg water temp you're talking about?

snyper wrote: »

There are also, air source heat pumps that have the ability to monitor the temp and will heat them selves automatically to prevent freezing up.

A slight extra inefficiency there then (alright I'm just nit picking )

snyper wrote: »

Armed with the above information the "difference" in cost for the ground source is in the 1000's. I know 1 gent that paid 38k for a vertical installation ex the heat pump!

Mine was 11K for a horizontal ground loop including HP but excluding UFH / Rads / Cylinder etc.

AckwelFoley

KAGY wrote: »

Mine was 11K for a horizontal ground loop including HP but excluding UFH / Rads / Cylinder etc.

Yea, with the vertical drilling is where it gets expensive

Horz is not so bad.

The Daikin heat pump uses refrigation tec and coolant and has a weather compensating ability to increase efficency.

galwaytt

fwiw, and we have to bear in mind that the majority on here are better, rather than ill-, informed, a lot of this is causing confusion to the man on the street, as it were.....

We have a 98 sq m, 2.5 storey, 3-bed house. 1 bathroom, 1 ensuite. Washer/dryer, dishwasher, std elec load (tv etc etc). It has ufh in concrete on ground floor, ufh in timber on first floor, and rads on 2nd floor. House is heated by a NIBE Fighter 360 Air-Water unit (Aerothermal). The NIBE unit supplies all dhw and space heating.

House is well built, but due to only being heated by the above unit (read: electric), scores as a B2, instead of an A-anything.

Electricity therefore, is the only energy source whatsoever - for appliance, lighting, space heating and dhw. Has Nightrate meter fitted.

For the two month at end of 07, house occupied with 2 x adults + 1 baby (read: constant washing/drying/heat.......:rolleyes:), the ESB bill for TWO months.......was Eur 243.

Personally, I think that's good - no gas, no coal, no timber, no firelighters etc etc etc......

For that scenario, the Aerothermal unit works. It was also very easy to fit, and the cost of it was 5k iirc. I can't see how 10k/15k is justifiable for ground source units at those prices, I just can't............

AckwelFoley

For the two month at end of 07, house occupied with 2 x adults + 1 baby (read: constant washing/drying/heat.......), the ESB bill for TWO months.......was Eur 243.

Personally, I think that's good - no gas, no coal, no timber, no firelighters etc etc etc......

Iy will be cheaper again in a years time all being equal.

The first year the consumption is always higher as the house dries out.

mjffey

Hi Galwaytt,

I'm interested in your Air to Water story. Where did you buy it, because the price is very attractive.

AckwelFoley

galwaytt wrote: »

It was also very easy to fit, and the cost of it was 5k iirc. I can't see how 10k/15k is justifiable for ground source units at those prices, I just can't............

mjffey wrote: »

Hi Galwaytt,

I'm interested in your Air to Water story. Where did you buy it, because the price is very attractive.

Be careful there.. i know of an air to water system that can be bought for the same money.. even cheaper BUT it doesnt includ the entire system of buffer tank and indoor control unit.

The Air to water unit i know, that is very common is an 11kw unit. The pump itself is only 3,500.. and thats what alot of guys price, but this unit comes with a control house unit that has the elcctronic controls the expansion vessel and the inverter tec unit in it that brings the price up to close to 7k. Essentially although its 11kw, it only consumes as much energy as it needs and does not require a buffer tank. Then you add the price of the combi tank in tank ..another 2500, and you hot closer to 10.

So be careful what exactly you are getting for the price.. ie.. does it include everything

gummibear

Just wondering if anyone else shares my concerns as regards the next 15 yrs or so and elec prices?? A few weeks back we heard all about the plans for overhauling our power stations to reduce or even eliminate dependency on fossil fuels... great news and just what we need to make systems like heat pumps a success... except... this overhaul is going to take about 15 years and cost BILLIONS... just how do we expect this to be funded if not through higher electricity costs (and our taxes too i guess), and I mean much higher. thats what turned me off burying close on E20k in a heat pump system for my upcoming build. i just reckon it will be less of a gamble to go gas for now and consider something greener in 10 years or so, plus the cost of installations should come down as more competition emerges?!?!? Just my opinion... who knows?:eek:

sinnerboy

It is very scary .

On the plus side

We can build passive houses which require no space heating

We can refurbish existing buildings to reduce space heating demand

but

We will always still need energy for hot water ,heating ,cooking ,tv's, lighting

pv technology is not up to the chalenge . not yet anyhow .

solar thermal is not reliable all year round

bio fuel production is leading to starvation or least hunger in places like Haiti + Mexico as food production activities are diverted

People in China , India and Africa surely deserve to aspire to economic growth and consumer "comforts" enjoyed in the West - and we ( the human race ) will consquently see an even faster accelartion of the depletion of fossil fuels

Nuclear power anyone ?

( Or in classic Irish style , maybe we just let the British supply that to us via inter connector )

ircoha

Foleyart wrote: »

...... For a large house you a talking about a 14KW pump.The heaviest draw in most houses is an electric kettle which is about 1KW. Just to put it in perspective......

Most electric kettles are at least 2kW
Most electrically heated showers are 8kW plus.
Most electric ovens are 2kw
Most electric rings on the hob are between 2,5 and 4kW EACH which is why you need at least 6 sq if not 10sq for the cooker/hob and 10sq or better for the electric showers

gummibear

sinnerboy wrote: »

Nuclear power anyone ?

( Or in classic Irish style , maybe we just let the British supply that to us via inter connector )

Well they have been supplying us with radiation for a long time...
But seriously I think our children might have better luck with all the technologies you mentioned above but for now the majority of people seem to be going for tried and tested. (Apologies for going off-thread here) ... Just looking forward to hearing some success stories for geo etc. in about 5-10 years time and then I can take the plunge and change over... hopefully!:o

Steve.g

Hi I have am air to water Panasonic heat pump here in Ireland. . Have a new home which is over 2200sq ft. Got bill there for 60 days which is last 2 months. It was €642. which i think is very very expensive. Can anyone help me out here. Would anyone know much about it? Thanks

KCross

Steve.g wrote: »

Hi I have am air to water Panasonic heat pump here in Ireland. . Have a new home which is over 2200sq ft. Got bill there for 60 days which is last 2 months. It was €642. which i think is very very expensive. Can anyone help me out here. Would anyone know much about it? Thanks

First thing to confirm is if this bill and the one before it are estimated bills or real readings.

Calahonda52

OP has same question running here:
http://www.boards.ie/vbulletin/showthread.php?p=102025934

It would also help if he provided some intel on house spec and occupancy

murphaph

And if this includes the "drying out" phase of the floor screed.