fresh air for heat pumps

[Jim Baird]

Pardon my ignorance, but does fresh air supply for heat pump's fan-coil unit have anything to do with the spray urethane insulation?

A new house had the foam applied to roof deck and floor deck undersides, and fan-coil units in both areas had fresh air ducts for the units.

It is equipment specific, as codes don't require it, to my knowledge.

Is the fresh air supply there because of the foam?

[Terence McCann]

Originally posted by Jim Baird

Pardon my ignorance, but does fresh air supply for heat pump's fan-coil unit have anything to do with the spray urethane insulation?

No, at least to the best of my knowledge, it doesn't. Reason I'm vague is that you never know what the local AHJ has to say about it. Call the building department to be 100% sure.

Does the fresh air come in through a heat recover wheel? Would be nice if it did.

With new houses being built tighter, with better insulation, it's advantageous to bring in X amount of fresh air to provide better indoor air quality. I'm sure ASHRAE has standards on air changes.