HamNCheese wrote:

I have a bathroom exhaust fan I installed in the basement to vent out
the cat litter smell. I let this fan run 24/7. I'm debating if I
should put it on a timer to only run a few hours a day. My question
is, how much is it probably costing me a year in electricity to run
the fan all day and all night as I have been?

An N-watt thing running 24/7 costs about $N/year at 10 cents/kWh,
eg $20/year for a 20 watt fan, but exhausting C cfm of house air adds
24hxCxDD Btu/year to your heating and cooling bills in a DD degree-day
climate, eg 24x60(4954+1101) = 8.7 million Btu/year for a 60 cfm fan
in Phila, with 4954 heating and 1101 cooling degree days per year
(with a 65 F base temp), about 100 gallons of oil or 100 therms of gas
or $256, with electric resistance heat.

Nick