Doctor_Frasier_Crane t1_jefazl5 wrote on March 31, 2023 at 4:22 PM

I would assume that the HVAC unit in your attic is the furnace & vent pipes. Do you have a separate AC unit outside on the ground somewhere?

The problem with having HVAC in the article is the heat/cooling loss from improperly insulated vent pipes. So if you enclose the space with spray foam or other method on the underside of the roof sheathing, your HVAC system doesn’t have to work as hard.

https://buildingscience.com/documents/building-science-insights-newsletters/bsi-119-conditioned-unconditioned

https://buildingscience.com/documents/bareports/ba-0305-why-it-s-so-important-and-troubling-to-keep-ducts-and-equipment-in-conditioned-space/view

haxxer_4chan OP t1_jefbaq7 wrote on March 31, 2023 at 4:23 PM

It's actually just a SpacePak air handler, so no heating equipment or AC compressor, just the intake, handler, and some ducts, though it seems those might also be important to keep in a relatively conditioned space

Doctor_Frasier_Crane t1_jefc3r2 wrote on March 31, 2023 at 4:29 PM

Agreed. Ducting tends to be leaky, and any insulation on them is likely maximum R-6 or R-8. So heating/cooling loss and negative pressure on your living space.

What do you have for heating & cooling then? Baseboard heaters, mini-split, or something else?

haxxer_4chan OP t1_jefkmp9 wrote on March 31, 2023 at 5:24 PM

Radiator heating with a boiler in the basement and separate AC systems for upstairs and downstairs