Air Source versus Ground Source Heatpumps

[rkinsella]

Hi folks,

I have heard reports that Air Source heat pumps are higher maintenance when compared to Ground Source Heat pumps? That Ground Source is around longer and is a more tried and tested, and trouble free technology.

I have also heard that Ground Source Heatpumps are more efficient with less expensive running costs. As the Ground Source is likely to be warmer than the Air Source for those times of the year when you to generate more heat. Has this been anyone's experience?

Appreciate any feedback, thanks.

Ray K

 

[stem]

I don't know about how long each type has been available, or the relevance of that. But both technologies have been available for decades.

The air source heatpump we have (Mitsubishi City Multi) does not produce as much heat when the outside air temperature drops. (Just when you want it most) When the outside air temperature approaches freezing the outdoor unit ices up and has to defrost itself. This takes about 15 to 20 minutes every hour and no heat is provided during this time. Therefore to maintain a internal room temperature of 21 degrees C, it has to be left on for 24/7 during very cold spells. Which is normal for underfloor heating, but ours is air heating / summer cooling, so we usually use the time control. Although it was the latest technology when installed 10 years ago, newer technology is probably better.

A friend who has ground source heating reports that the icing up does not happen with his because the ground temperature stays fairly constant and does not freeze once you are more than a few inches below the surface. However it was expensive to install because of the additional ground works, and the area of land required to contain the underground pipework.

Reliability with our air source heatpump has been very good though, without any maintenance issues in 10 years. No breakdowns at all, and apart from changing the filters from time to time and regular servicing no other new parts required.

 

[bernardgreen]

As Stem has said Air source can ice up in cold weather.

Ground source may need to have anti-freeze in the ground coils which if this leaks can be environmentally un-friendly.

Ground water source is another option using a well, stream or bore holes