A friend of mine is doing a gut renovation on a 1904 house in Fargo, ND CZ7. I put together the survey and a preliminary HVAC design for it for them. What the owner needs now is a mechanical contractor who will take it the rest of the way and put the system in.

The house is 1,205 sq ft conditioned on the main floor and a finished half story, over a full basement and a small crawl. Scope is a single zone ducted air source heat pump with a nominal 10 kW electric resistance auxiliary, horizontal air handler in a conditioned attic over the north wing, all ductwork inside the thermal envelope. The existing gas furnace stays to serve the basement and crawl only at 60 F and is out of scope. A balanced ERV is already selected and is a separate system with no connection to the heat pump ductwork.

Preliminary numbers: 29,722 Btu/h heating at a -20 F design condition, 15,110 Btu/h cooling, 1.26 tons, climate zone 7. Infiltration is the soft spot and there is no blower door result yet, so the design carries the leaky end of a 5 to 9 ACH50 estimate on purpose.

Attached is the design package and a flat contractor entry sheet. The package is a measured survey, a preliminary load, and a proposed duct layout with segment lengths and path losses. The entry sheet is the same data as flat values, one row per surface with area, assembly, U value and SHGC already resolved, so the house can be dropped into load software without retyping it out of a narrative. Neither one is a certified Manual J and I do not represent them as one. The cooling calculation uses a simplified CLTD method at a single solar hour and the package says so.

What we are after is somebody who will run their own Manual J, S and D on that data, select the equipment, and install it. The design is his. This is not a rubber stamp request. It is meant to save him the survey and the routing walk and to give everyone a room level basis for the conversation instead of square footage.

Where it is stuck is equipment. The leading candidate is the Bosch IDS Edge Max, 2 ton, with the 10 kW kit, and there are open manufacturer questions I have not been able to close: the certified AHRI data pairs a BIVA indoor unit while the current product spec describes a BIVB cabinet family, two certificate numbers appear in Bosch’s own documents, and with the heat kit installed only one dip position is usable and it solves above the stated airflow per ton ceiling on a clean filter. There is no published sensible and latent split for that air handler either, so the Manual S cooling check cannot be completed. Carrier 27VNA with an FE5B is a live alternate and a verified constant airflow configuration may avoid the fixed tap problem entirely.

So: does anybody know a mechanical contractor who services Fargo and has actually commissioned variable capacity cold climate ducted heat pumps? Names, referrals appreciated, or any direction appreciated.

Happy to answer questions on the assemblies, the enclosure, or the load. Thank you