Yes it can. Just as 90 degree temperatures outside in the summer time can be used by your air conditioner to cool a house to, say, 70 degrees.

In fact, using 60 to warm to 70 using geothermal is much easier (and more efficient) than using 90 to cool to 70 using ambient air temperature.

Think of a heat pump as an air conditioner you can run in "reverse", to heat the indoors and cool the outdoors. Or in the case of geothermal, heat the indoors and cool the ground up to 400' below your house. (Or cool the indoors and heat the ground.)

There is no question that radiant heating is great. It is, however, unbelievably cost prohibitive if you still plan to have central air conditioning, because you are essentially paying for two completely independent systems. This was one of the main reasons why we switched away from it on our project. I was talking with a radiant guy the other day and he agreed stating that conventional HVAC cost about $3-5 a sq. ft., radiant alone costs $12-15 and if you are doing both, factor in $17-18.

The other reason is that radiant heat, while very comfortable and efficient, still relies on either gas or electric, while geo-thermal uses the earth's constant temperature to heat the house with minimal electrical requirements. If you can afford to do the radiant, though, it sure does feel nice to have a warm floor throughout the house.

__________________
Luxury and green living under one roof
www.bancroftgreen.com

many many questions here so please excuse me for taking up time/space on the board.

1. Can a heat pump system be zoned? if not, doesn't this cause the same issue in traditional heating/cooling where parts of the house are colder/warmer than others?

2. If you install a vertical loop, how much of your back yard do you lose? is it possible to put pavers/lawn over the loop or do you need some sort of access?

3. what is the probability of the loop being shifted/cut through tremors? it's my understanding that philadelphia sits near a small fault line?

4. if I'm building from scratch, what's an approximate cost comparison for installing, say a two-zone traditional system vs. a geothermal system?

I'm asking because my gf and I decided that we're going to try to build a place rather than buying an existing one. since we're starting from scratch, we figure we will have lots of flexibility.

__________________
No matter where you go, there you are. (b.banzai)

1) Yes, zoning is possible
2) If it is new construction, I don't think you would have to lose anything. They could do the drilling under your house. Worse case, the hole is only 6" wide, so you might have to have some sort of man hole cover.
3)No clue. I would wager a guess, the probability of that happening versus a regular heater giving out are pretty small
4) See my previous post

PM me if you have any more questions. If you are looking to build a green house, why don't you just buy one of ours.

__________________
Luxury and green living under one roof
www.bancroftgreen.com

Actually it depends where you live (ie how cold it is outside). In colder climates you may need to supplement the geothermal system with an electric heating system. The operating costs are still low as you only heat the house to the point where the geothermal system can take over.

Prospective home buyers need to understand that although these systems generate "huge savings" they are paying a substantially higher upfront price for this technology and that the return on investment is quite long.

The payback period can be hard to calculate since residential geothermal systems are still fairly new here in the States (in Europe systems have been installed for the past 7-8 years) and no one really knows how long they last.

Numbers aside, the technology is clearly the future. It works great and is a formidable alternative to burning fossil fuels.