Where is the best place to put the exhaust in a whole-house exhaust ventilation system?
user-1068185
| Posted in Mechanicals on
The house I am planning to put at least one 2,000+ cfm whole house exhaust fans is in zone 4B (hot and dry, Central Valley, near Fresno, California, but sometimes very humid and foggy in the winter months). Can the exhausted air go into the ventilated attic space or should it have a dedicated duct that goes through the roof? The house was built in the 1950s and remodeled with an additional den and an upper story with two bedrooms and a bath on the second story. It is about 2,700 square feet, counting both lower and upper levels.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Barbara,
A whole-house fan can be vented into an attic, but only if the attic includes large enough gable vents or ridge vents to handle the air flow of the fan.
The best whole-house fans are manufactured by Tamarack. Here's what the Tamarack manual says: "Make sure that you have adequate exhaust area out of your attic. This can be accomplished with a combination of roof, ridge or gable end vents. The HV1000 [ a 1000-cfm model] requires a minimum of 3 square feet and the HV1600 [a 1600-cfm model] requires a minimum of 5 square feet of attic exhaust area."