"Home Guy" wrote in message
...
Larry Fishel wrote:

I have a temperature sensor mounted about 1" under the plywood
roof deck in the attic and it went from about 120F to about 100F
during the watering.

The temperature at this point may be misleading (most affected by the
sun, least affected by venting).

I don't agree.

Air currents in a soffit-ventilated attic will flow primarily from the
intake point (the soffits) up along the underside of the decking to the
peak where the exhaust fan is located.

You better learn about intake. You're pulling air in from your passive
vents near the ridge as well. Air is supposed to flow as a sheet, not some
hacked up system you believe you "designed" by throwing a power vent up
there.

You're probably better off not running the power vent, pulling air _only_
from the soffit. This is of course based on if you have at least the
minimum intake & exhaust venting needed for the square feet involved.

Did you ever calculate how much venting is actually needed?