Air to Water Heating for Domestic Houses?

Lame Donkey

Long time reader 1st time poster;

Basically I've been out working as a Surveyor for the last 10 years and decided to go back to college at - which I have to say has been a tough transition. I'm currently working on my thesis, the thesis topic I have chosen to write about is “AIR TO WATER HEATING SYSTEMS - THE FUTURE FOR IRISH DOMESTIC NEEDS", basically I decided to focus on a "greener" option to heat the apartments/houses than storage heaters/oil.

I would any views on this system from past or present experience (either good or bad) or if anyone has information you may be able to forward me in relation to this subject with regard to published books, journals etc. it would be much appreciated.

While it's not hard trying to companies willing to sell you the product, it's the proven literature evidence that this product is suitable for Irish Domestic needs is what I'm after (or any evidence for that matter).


Many thanks,

BryanF

Lame Donkey wrote: »

Long time reader 1st time poster;

Basically I've been out working as a Surveyor for the last 10 years and decided to go back to college at - which I have to say has been a tough transition. I'm currently working on my thesis, the thesis topic I have chosen to write about is “AIR TO WATER HEATING SYSTEMS - THE FUTURE FOR IRISH DOMESTIC NEEDS", basically I decided to focus on a "greener" option to heat the apartments/houses than storage heaters/oil.

I would any views on this system from past or present experience (either good or bad) or if anyone has information you may be able to forward me in relation to this subject with regard to published books, journals etc. it would be much appreciated.

While it's not hard trying to companies willing to sell you the product, it's the proven literature evidence that this product is suitable for Irish Domestic needs is what I'm after (or any evidence for that matter).


Many thanks,

http://www.boards.ie/vbulletin/showthread.php?t=2056245862&page=2

I don't have much positive to say on the subject, but ill have a go:D. I see them as a form of Air-con that has its benefits where other heating sources cannot be used. good ones are more expensive than actual real:rolleyes: renewable options, and adding up the the embodied energy consumed makes the immediate case to better insulate, orientate/design a home to avoid the use of ASHP. problem with the whole scheme is they appear cheap and in the short term they can be.

the exception to the above is the type/ sort of heat pumps available as part of an efficient MVHR systems in an air-tight and well insulated home

Do-more

One aspect I'd suggest to look at Lame Donkey in relation to ASHP use in Ireland is the climate.

I now live in Sweden where both air to air and air to water heat pumps are very popular, when I lived in Ireland I looked at installing an air to air heat pump but decided against it because of the advice I got at the time concerning the much higher relative humidity in Ireland compared to Sweden.

From what I remember of the explanation at the time, a good air source heat pump will be stripping about 7 or 8 degrees from the air passing through it and if the relative humidity of that air is high then at ambient temperatures below 7 degrees you then run the risk of ice forming on the fins of the heat pump. Once you have ice formed then the heat pump has to go into a de-icing cycle of which there are various different methods but which will all consume energy.

Might be an idea to put some figures on this and see if the advice I got at the time was valid or bunk.

Outkast_IRE

Do-more wrote: »

One aspect I'd suggest to look at Lame Donkey in relation to ASHP use in Ireland is the climate.

I now live in Sweden where both air to air and air to water heat pumps are very popular, when I lived in Ireland I looked at installing an air to air heat pump but decided against it because of the advice I got at the time concerning the much higher relative humidity in Ireland compared to Sweden.

From what I remember of the explanation at the time, a good air source heat pump will be stripping about 7 or 8 degrees from the air passing through it and if the relative humidity of that air is high then at ambient temperatures below 7 degrees you then run the risk of ice forming on the fins of the heat pump. Once you have ice formed then the heat pump has to go into a de-icing cycle of which there are various different methods but which will all consume energy.

Might be an idea to put some figures on this and see if the advice I got at the time was valid or bunk.

your spot on that is exactly the problem in this climate, last winter i viewd one air to water heat pump that spent most of its time in defrost mode, it made the bills go mental as it was running constant in order to defrost itself.

Lame Donkey

thanks for the replies,

following some research and meetings with a manufacturer, they now advise that they have over come the defrosting problem, the how - im looking into this at present.

the main concern i find at present is while they are capable of heating our homes here in ireland, they advise the sizing of the heat pump is where the efficiency lies. basically i've been informed that they can now produce air source heat pumps that can take heat from temperatures as low as -25, however they advise the key to sizing a heat pump for irish temperatures is to allow for an average temp of -2 to -3 for the best results (both efficiently and financially) and once the temperature drops below -4 to -5 a secondary heat source back's up the system - which is usually electric input but can be adapted to suit an oil/gas burner and or solid fuel stove?

the also advise its best to use with underfloor heating as the main output.

cheers,

Handballer

Hi Guys,

Am thinking of this(air to water with underfloor heating) as a contender for our new house, has anyone heard anything bad about it lately?

Appreciate any thoughts.

bee06

Handballer wrote: »

Hi Guys,

Am thinking of this(air to water with underfloor heating) as a contender for our new house, has anyone heard anything bad about it lately?

Appreciate any thoughts.

Loads of info in the Renewable Energies section that you can read.

NH2909

Just came from the self build in Belfast We are doing the same as you Handballer and I first started out looking at Goe systems only to find our water table is too low. Air to water is our next option I was made aware that most if not all the installers fit a storage tank for the hot water into which is built a immersion unit for when the system cannot produce hot water Only two suppliers that I talked to were prepared
to admit this and one was prepared to leave it out of the system if required The danfoss agent are boasting a unit within their heat pump
that recycles the gas not used by the heat exchanger to further assist in the heating of the hot water system (something like a condenser boiler is the only way I could describe it).I was impressed by the Toshiba system as well but a lot more research to be done yet.

Handballer

What are your thoughts on geothermal v air to water, would you go for the Geothermal if it was an option?

JD6910

Handballer wrote: »

What are your thoughts on geothermal v air to water, would you go for the Geothermal if it was an option?

simply advice: insulate and airtight the house thereby reducing the heat demand. then pop in a simple tried and tested boiler and solar. no matter what oil and gas prices do - if your heat demand is low due to good insulation and airtightness - oil and gas prices makes little difference. just remember to redcue the demand at the start with savage insulation etc...
boiler's are tried and tested for years. any plumber can maintain them. parts are cheap and readily available.you are in control on when you turn it on etc.. heat pumps are on all the time even when you missing from the house.

BryanF

JD6910 wrote: »

then pop in a simple tried and tested boiler and solar.

assuming you can comply with the 2011 part L regs..

NH2909

I would go for geo over air to water if I could that's if the facts are true The temperature in the ground is supposed to be around 5 or 6 degrees higher
than that available in the air Now those selling the air to water claim that the
the temperature leaving the ground to heat the line going into the heat exchanger and the loop bring cold back from the heat exchanger drops the ground temperature over a 2hr period close to air temperature. Geo installers
claim if this happens that incorrect calculating of the house requirements has been carried out. I hear a few people saying that after the ESB loss during the recent storms their systems are working over time and are not looking forward to the next bill I presume insulation has a lot to contribute to this.
As regards oil and gas its a fact that these are not replenishing so other systems have to be considered.