Builder Sprayed Insulation All Over Furnace In Attic

Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used.

Builder sprayed insulation all over furnace in attic.

They also need to seal off areas of air leakage to the outdoors. A while back i wrote about the incompatibility of putting an atmospheric combustion furnace in a sealed attic. Otherwise humidity will quickly creep into your attic. You can build a small enclosure around the furnace with rigid foam insulation then pick up the insulation on the ceiling inside the enclosure.

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. If the furnace is a fuel burning one be sure you provide air for combustion. If the air is not piped in directly to the furnace the attic space would be considered the plenum. This puts the furnace in at least semi conditioned space.

I found instead a vintage 3 ton ac unit with 1 rigid insulation taped all over it and insulated flex duct snaking all over the poorly insulated attic. The attic floor needs an insulation value of r30 40. Most often the attic is sealed by installing spray foam insulation at the roofline thus bringing the attic inside the building enclosure and turning it into conditioned space directly or indirectly. The attic is the worst place to install hvac equipment and duct work.

If the builder says that will cost more then use the money you would have spent on the foam insulation and attic enclosures to do this. Gable vents and soffits are the big culprits here. In a proper spray foam job a contractor doesn t just spray foam all over the top of your attic and go home. But then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.

The rigid insulation was saturated from condensation. A plenum is the source of combustion air. If you don t have a crawl space or a basement then it can be a challenge to place a furnace on the ground floor of the structure. A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits.

If this house has a basement then both handlers or furnaces should be installed there. You might not receive the same air movement benefits if the unit is in a garage either. A case of incompatibility. If you pipe the air in directly to the furnace and it does not use attic space air then you can use sprayfoam.