Heat pump strategy
I posted the following question on HVAC Talk and only received a few comments mostly preferring traditional heat pumps, even if oversized. I’m thinking folks here may have different ideas. Your thoughts???
Hoping those here can provide some guidance on a heating / cooling strategy for a new construction home
I’m looking to build in climate zone 4C or 5. The house plans I like are open floor plan single level ranch styles of approximately 1800-2000 square feet I plan to insulate above code with major effort in air sealing to get below 2 ACH/50. Heat loss calcs come in approximately 24K BTU with cooling at 16K BTU. I would plan to build on an insulated slab and keep ducts inside the conditioned space with potentially two zones. My wife has vetoed any ductless wall units. We assume natural gas will not be available. We will provide adequate ventilation.
A few alternatives I’ve thought about:
a) Conventional but high efficiency heat pump – something like a 2 ton Carrier Greenspeed 20
b) Conventional single speed heat pump – low cost but perhaps adequate due to low load
c) Mitsubishi or Daikin inverter mini split with 2 ton air handler (MVZ or FTQ) – are these better or worse for modulating than the Greenspeed option?
d) Two 1 ton single zone ducted mini splits – provide redundancy for breakdowns and zoning, split the flow from the ducted unit with short duct runs to rooms, modulates
e) Multi zone mini split with two ducted inside units – split flow as in d)
What are your thoughts on cost, efficiency, comfort, etc? Is new construction on a path to using ducted minisplits in the future vs conventional systems?