UnderAire™ Crawl Space Ventilation Fan per 1

mfr: Tjernlund Products Tjernlund UnderAire™ crawl space fans ventilate excess moisture -- a cause of mold, mildew and wood rot. Increases air circulation to fight condensation.

Constant operation helps vent radon, treated wood off-gassing and odors that might otherwise migrate into living areas.

The only crawl space ventilators with a special "suitable for damp locations" ETL listing.

Galvanized faceplate can be cut to fit openings smaller than 18" x 9".

How to determine the number of UnderAire™ Ventilators needed: Calculate the cubic area of the crawl space by multiplying the length x width xheight. Divide this number by 15 to determine the minimum CFM necessary to fully ventilate the space in 15 minutes. Example: 20' wide x 40' long x 3' high crawl space = 2,400 cubic ft. 2400 cubic ft. ÿ 15 minutes = 160 CFM of ventilation. Choose two V1 or V1D ventilators or one V2D ventilator.

Two fans and large faceplate sized for ventilation openings through block foundations. Includes freeze protection thermostat, dehumidistat and pre-wired 6' power cord.