[Greenbuilding] recommend bath exhaust fan

[dpwentling at comcast.net]

Visit www.conservationtechnology.com for exhaust only ventilation system. 

One energy efficient fan connected to four grilles can operate for 38 watts. The grilles open and close using an elastic technology which requires no electricity. When the grilles are in the "closed" position they allow 8cfm of flow. At 34% humidity the grille starts to open and at 70% RH the grille is fully "opened" allowing 50 cfm of flow. 

Variations of the grilles are available with motion only sensor (open for 25 minutes with 50 cfm then close back to 8 cfm), motion & humidity combo, switched only (same as motion only operation but operates manually by momentary switch) and switched humidity. 

Fan ($300) grilles ($85 - $125), and ductwork ($150) means under $900 one can have a continuous background ventilation system which can sense occupant usage and increase or decrease flow from four rooms for $34/yr (based on 8760 hours of operation and $0.10/kWh).

Recommend humidity only in full bathrooms, motion only in half bathrooms, and switched humidity in the kitchen (locate away from the stove to avoid grease).

--
David Wentling