Chicago Bob wrote:
I don't need a complex programmable thermostat. All I want is to know how
many hours that fan has run so I know when to change the air filter. The
fan runs frequently in the summer and winter, but very infrequently in
the spring and fall. How often the fan runs is determined by temperature.
You can go weeks - or months - without the fan running at all.


You never turn the fan on for like circulating air or freshen up the
stale indoor air specially when cooking, etc.? Filter gets dirty not
only depending on how long fan ran, it also depend how much dust is
generated indoor if there is pets, plants... I'd think under replacing
it may be a bad idea. I'd rather over replace. My filter size is
16x25x5. I replace twice a year. They don't look too bad when pulled.
But It gives me peace of mind. Programmable saves energy depending on
how you use it. I use it in my house and out at cabin.