I'm looking over a J load calculation and on the Design Information page, under Heating Summary, what are the "Ducts" and the "Central Vent" entry's for? I'm assuming the "Ducts" for duct loss. Would "Central Vent" be for flue loss?

Ventilation.

Thanks Badger. The Heating Summary calculation has;

Structure: 42395 BTU,
Ducts: 2724 BTU,
Central Vent (151 cfm) 9447 BTU

There are no ducts in the house or vents that would flow that much air. I guess I'll have to call the guy that ran the calc and ask.

"Ducts" would be heat loss through the duct system. This is assuming you have ducts outside of the conditioned space, i.e in a ventilated attic or unconditioned crawl space. Ducts are typically only insulated with R6 or R8 insulation.

Central vent would typically be for fresh air makeup. Do you have a fresh air makeup vent or ERV?

I stand corrected. Thinking of another screen.

Thanks arkie

No to the ERV. Nor is there any duct work. Just radiant heat and mini-slits.

You need to communicate with the person that ran the calc. I hope you didn't pay a lot for this.

The central vent calculation is based on current fresh air requirements. I haven't received an answer on the duct loss in a ductless.

The fact that they included any duct loss at all for a ductless (&/or hydronic) heating system would be enough to cast great doubt on the accuracy of the rest of it.

I'm with Joe- this level of competence isn't something you'd want to be paying a professional rate for. With corrections for the gross & obvious errors it may be better than a WAG, but if the rest was as just sloppy you can't really count on that.

I got my answer on the ducts, his mistake and he reran the calculation for a ductless system.