They Spray Foamed the Attic & Encapsulated the Crawlspace... Now It's Too Humid

A contractor spray foamed the attic and fully encapsulated the crawlspace, but no humidity-control plan was added. On this HVAC service call, I inspect both sealed spaces, check the relative humidity and dew point, and explain why moisture can become trapped after spray foam and crawlspace encapsulation. I also determine whether separate dehumidifiers are needed for the attic and crawlspace and uncover another important concern with the furnace now that the crawlspace is sealed. Sealing a home can improve efficiency, but once the attic and crawlspace become part of the conditioned building envelope, moisture control and combustion air must be considered. Topics covered: High humidity after spray foam Encapsulated crawlspace moisture Attic and crawlspace dehumidifiers Relative humidity vs. dew point Furnace combustion air HVAC moisture control #HVAC #Dehumidifier #SprayFoam #CrawlspaceEncapsulation #HumidityControl