I installed an AirScape3.5e whole house fan. I don't think the fan is operating at its max potential. It just doesn't seem to cool the house down very much when running even when the outdoor temperature is much colder.
To add specific measurements to this question, I bought an anemometer to measure velocity of airflow (and have calculated some CFM readings by multiplying velocity by area of the vent/window). I measure 4150 CFM going into the attic vs 1794 CFM coming in from the window (with that being the only open window). These were measuring the air velocity at the center of the window/vent where I think velocity would be greatest. So I suspect actual flow to be a bit lower.
So it seems like of the air being pulled into the attic only about half of it is coming in from the window. How can I find out where the other air being pulled into the attic coming from? More importantly how can I improve the cooling effect of the fan? Would adding ventilation to the attic help? And side question, what kind of pro would I hire to help with this (e.g., roofer, HVAC, other)?
- The fan says that at its max speed it can move 3500 CFM of air. The manual says the attic needs 7 sq feet of net vent area. Manual is here.
- My attic measures 23' by 48' meaning it should have at least 23*48/150= 7.3 sq feet of net vent area (if it was built to the 1 sq foot of vent area per 150 sq feet of floor area).
- Attic has soffit vents along probably 3/4 of the two 23' sides. I think it also have a ridge vent (23' of ridge vent). No other vents.
- House built in 2001. NY Area. It's a town home, but attics are completely separated.