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.

I have the fixed speed ARUF374316 air handler for my Goodman GSH14036 heat pump. The Installation and Operating Instructions have a seperate sheet of paper titled "Supplimental Insert, Electronic Blower Time Delay Relay, B13707-35". There is a 7 second delay for the air handler fan to start after the condenser starts. There is a 65 second delay for the air handler fan to continue to run after the condenser shuts off. This TDR is currently operating properly on my system. Note that heat pumps require a certain amount of run time to reach optimal output temps. Even with a functioning TDR, I still get "cool" air for the first few minutes. The palm of your hand is about 91F, so any air at or near that temp will feel cool. Take care.

Carl Your thermostat is able to maintain it's setting at 68 degrees fah at outside temp of 14 degrees fah? And without aux Heat strips engaged? I assume the heat strip has been locked out? Yes, I would say an 80 deg supply temp with those conditions are entirely normal. IMO

I guess you are deciding whether you want heat pump or cooling only, and if heat pump, what low temperature you want to be able to use them to. My memory tells me that the cost of heat pumps was not much higher than cool-only when mine went in. The lower temperature heat pumps are going to cost more, but you may very well find that they will return more than that cost with a little calculation. The trouble with that calculation using fuel cost only is that it is significantly more expensive to operate a heat pump than resistance heaters. You'll have to be more creative to factor that in. IMO, mvthike's situation is what mini splits are made for, adding (a little) cooling to a home with established heating without ducts. There are a lot of heat only homes in climes with low cooling needs. ( A lot of them have window units running for a few weeks.) That is, of course, why the installer mentioned is "quite familiar" with that situation in the 'daks and far outside. This particular situation is complicated by the fact that the most economical heating fuel choice, for many, is not available. (Outdoor wood-fired boilers are not unheard of in that area. I bet there are dealers for those a lot closer than for the air-water heat pumps.) My memory of earlier posts combined with this one says mvthike's "overkill" response is partly due to the fact that this home is unoccupied more than it is occupied so payback with higher cost, highest efficiency, methods is going to be long at best and may reach never. Tigerdunes, I think that there used to be high wall mini splits with resistance heat. I think I saw info about them when I first started looking at them but they disappeared shortly afterwards. My understanding is that someone decided that heaters of that type with plastic cases were not a good idea. I could be all wrong about this. I do think that is available with their mini ducted equipment.