Few questions for the pros out there.
I have had a load calc done on my home: here are the specs below:
1700 square foot 2 story house with finished basement in Titonka Iowa
Heat loss@design------53,880 btu
Temp difference-------81 degrees F (70 degree inside -11 outside)
Cooling load@design---26,736 btu
Cooling load hours-----700
electric rate is $0.048 September to April and $0.077 May-Aug
Having this load calc done i am getting differences in system proposals.
Mcquay 3 ton single stage heat pump with 10KW electric strip and ECM fan
Contractor says he would use this and rely on some backup heat on the coldest days rather than oversize the system to avoid using strip heat, says its better.
Econar GeoSource Vara 2 Plus 4 ton 2 stage unit with 5 kw strip
This contractor says that this is the way to go. says 4 tons and 2 stages with a 3rd electric strip stage is best. says this system fits right in with my load calcs i had done. (There is a 3 ton version of this unit too)
Both units running in open loop. and both have desuperheaters
I am not to sure what to do. The prices are not to much different from one another. Contractor 2 says that 2 stage cooling i will have better humidity control in summer. (i do not have a humidity problem now, and my current 4 or 5 ton single stage ac keeps it comfortable)
Contractor 1 says that a 3 or 3.5 ton unit will have longer run times and keep up with humidity while making lots of hot water with the desuperheater and that in this part of the Midwest 2 stages are not needed as much as in the south. Though he did say that the Mcquay unit have an option for hot gas reheat for humidity control when hooked to a humidistat if i was concerned about it. (i am not)
I have not found a lot of info on the Mcquay unit, they appear to be more industrial units.
the Econar unit doesn't look to have really great efficiencies.
Opinions on this?