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.

I asked my installer about the refrigerant charge and this is what he said: The charge is 12 pounds of R410A for the system and 10 of lines + .6 ounces per foot for additional line lengths. We do not test super heat or sub-cooling on a new Acadia system start-up. We do on any other heat pump or AC system we install. The Acadia system is unique in that it does not come with any refrigerant from the factory, only a nitrogen charge. Per Hallowell instructions (told to me from Duane Hallowell himself), we weigh in the R410A charge according to the manual and start the unit, no further testing is required. Testing super heat and sub-cooling verifies proper charge. We always run these tests on any other system because we do not take for granted that the factory installed the right amount or that some has not leaked out by the time we get the units. With Acadia systems, we would only test sub-cooling afterwards if we suspected a problem with the refrigerant system. Does this sound right because they treat me as if this were my fault!

@dadoes, @Air and Energy Solutions - I wasn’t sure that I did understand how the defrost cycle works. Thank you for the correction, that helps. Now I’m wondering why we can send a man to the moon but not invent a heat pump that can defrost without blowing cold air into my home - forcing me to throw more electricity at it to solve the problem. Sorry I just had to vent (pun intended). Regarding the question of whether I was offered electric backup, the answer is no. My previous 15 year old heat pump did have it, but I was told the Bryant Extreme could handle the low temperatures I would experience in my location. It actually does seem to work ok when it’s heating, although I can’t be 100% sure because of the ongoing battle between heat mode and defrost mode. But I am getting air as warm as the low 90’s when it’s in heat mode. It’s the defrost that’s killing me. So it seems clear that I need to have the heat strip installed to deal with the defrost issue. But now that I know it goes in A/C mode during defrost I’m wondering if mine is going overboard. The air during defrost is consistently going as low as the 30’s and 40’s, with 27 being the coldest I’ve seen. A few of my neighbors (we’re all on the same top floor of a condo building) also just bought the same heat pump. The only difference is their condos are bigger than mine so they bought the 3 ton. I’m gathering temperature info from them also. So far I only have data from one unit for one day, but the lowest temperature I saw from his vent was 50 degrees. That’s not nearly as bad as mine. Could his defrost cycle be working better because he has the 3 ton? The heat pumps are installed on the roof and the sun is going to hit each one slightly differently. Would that make a difference in how much defrosting it needed and how cold the air will be during the defrost cycle?

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.