Hi all,

We have a newer two-speed attic furnace/HVAC unit which currently draws the
intake from a hallway ceiling vent right next to where I would like to
install a whole house fan to vent warm air into the attic to cool the house
in the summer evenings rather than run the AC.

I thought that we could use the existing two-speed furnace/AC blower to just
divert the incoming air into the attic and have it double as a whole house
fan. I think it would require some diverter valve to send the air into the
attic rather than back through the plenum to return to the house, but this
would obviate the need to cut new holes in the ceiling, install and wire a
whole house fan, open up more ceiling space to heating and cooling losses,
etc.

Clearly it may be more work than it is worth, but I was wondering if anybody
has tried something like this.

We live in SoCal near the coast, so we have cool evenings regardless of the
temperature during the day, and it makes a whole house fan an attractive
option, particularly since we have a 5 ton AC unit with 169 LRA at 240 VAC
(clearly oversized for our needs).

Thank you,

OD