Air source heat pumps don't make sense in areas where winter temps frequently fall below 32 degrees. Once you get below freezing, you will be running the auxillary heat a lot. If you decide to go the air source route, you will want a second stage gas fired auxillary heat. I live in the mid-atlantic region in the mountains and selected GT. That choice was coupled with a blown cellulose insulation package. My other choice was a propane heat/electric AC with a foam insulation package. Both options were roughly the same install cost. Both would have provided similar energy efficiency. At the time we selected, propane was 3.75 a gallon and rising (with no end in sight) so we went with GT. The delta cost for the GT system (above the cost for a HE propane heat and electric AC system) was $15,000 for the heat pumps and loop plumbing (including pumps) plus $17,000 for digging the pit. The pit excavation should not have cost as much as it did but it is a 12 ton system and the hole was gigantic (120' x 48' x 6'). We live on a mountain and hit a bunch of boulders that required special equipment to get out. Rocky soil also required a 1' base of stone dust to cover the loop piping. The total cost for the GT HVAC system including all ducting was $50,000 plus the pit excavation cost of 17K. It is a large investment and I would only recommend it if you plan to live in the house a very long time. My heating bills are great - maybe 300 dollars maximum a month during peak winter for an 8500 square foot home (5900 living and the rest a condiitoned but unfinished basement). Make sure that whatever equipment you choose can be maintained by more than 1 very qualified HVAC company who has many years of GT experience. In my area there is only 1 GT company who has over 20 years of experience but I am stuck with them for maintenance. There have been times when I wanted to fire them but cannot. Local competition is a good thing. Also - if you build a tight home make sure that you consider ventilation and dehumidification in the HVAC design. I wound up adding both a whole house dehumidifier and energy recovery vent after we moved in becuase we had basement moisture issues as well as stale air in the winter. Tight homes are great for energy efficiency but can create health issues too. It is easy to deal with as long as you plan for it. Good luck with the build.

tigerdunes: The installer is also the Amana service person. We have a 10 yr parts and labor contract w/Amana. I could call Amana and see if they will send over another company at no charge to us, but we thought if it was an install problem, then Amana wouldn't cover the service. So... 1) Is there any way we can tell if there is an 8kw heat strip installed? And, if it is, is there anyway for us to tell whether it is hooked up properly AND working properly? 2) Again, the installer/service person "tells" us it is working (i.e., he put the compressor into defrost, came inside and looked at something and said "yup, the heat strip is working") He has even called a couple other HVAC people to ask them questions while he was here. He feels since we are getting 36,000 BTU's of cool and only 30,000 BTU's of heat (with the 8kw strip) that it will always be colder. But what I've read on other posts is that the heat strip has a 30/70 and I wondered if perhaps in defrost mode that it is only operating at 30% capacity??? (Like I really know what I'm talking about, so forgive me if I'm WAY off base). We did have him adjust the CFM down to 1100. It was running at I think 1400 and the noise through the duct/vent was too much (the vents were cleared out, though). Also, in the summer, it would only run for about 4 minutes, not enough time to help w/the humidity in the house. When the temps are above 40, the "heat" runs for 9-15 minutes normally. If you or anyone else has any further info for me, let me know. Otherwise, I will try to get someone else to look at it. I'll let you know.

It'll certainly, on average, cost more to heat than cool. A lot of areas now impose summer electrical rates which are higher than winter rates so they may be close. As for determining the cost effectiveness in relation to higher initial costs of higher SEER ratings, there may be more sizzle than steak. Compare the increase in energy savings with the higher efficiency units as opposed to the actual higher cost of a higher efficiency unit. The expected life cycle on a unit is 10 years so figure the energy savings you will experience in your area and see if it will shadow the initial and ongoing maintenance costs. Keep in mind the newer units also have a maintenance schedule that will be required by most companies, which is going to increase those costs. If your energy savings is more than the overall cost of the unit in a 10 year period, then it's worth it. But for the most part, I think you'll find it won't.

Our fuel costs are £0.14 per kW and £0.5 per litre of oil. We were burning through oil at an insane rate. We installed a 6kW solar PV array to help the ASHP during the day, and also upgrade our wood burning stoves to help boost temperatures in rooms rapidly. Really interested to see the efficiency in the cold months ahead.