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.

When considering Geo and payback periods keep in mind that there is a cost associated with running the pump for groundwater that is almost always not considered in the calculations that makes high efficiency variable speed DX equipment very close to Geo numbers. Here is a link that might be useful: Air Conditioning and Heating Repair Made Easy

hstlnflw what is your location? what size home? you are replacing a 2 1/2 ton system? you are strictly all electric? how did old system perform both cooling and heating? any comfort issues? here are the performance/eff numbers from the AHRI HP Directory. according to the directory, the only matching system using the communicating air handler is the C01. and you should note the rather mediocre HSPF heating efficiency. The C04 air handler is not listed as a matching system. 3591483 Active Systems XL15I WEATHERTRON TRANE 4TWX5030A1 4TEE3C01A1 30200 12.50 15.00 29000 8.50 17600 1 HRCU-A-CB Also with the communicating air handler, you would want the matching XL900 communicating thermostat. I personally would forget the above configuration and go for the following. 1382160 Active Systems XL15I WEATHERTRON TRANE 4TWX5030A1 4TEE3F39A1 30000 13.00 15.75 30000 9.00 18000 your thermostat choices could be the 802,803, or HW VisionPro IAQ which is preferred. as to the heat strip, what size do you currently have? Trane offers a 7/12 KW and 10/15 KW staged modules. The idea that you might requirew a 19 KW seems extreme and not necessary. as far as price, nothing special here. I have seen three ton XL15i systems for about the same price. IMO Good Luck!

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.