I have 20"x20"x4" air filters not the Typical 1". These 4" type last much longer than the 1" however the application does not discern the difference. I'm changing my filters way to often. Another feature request would be for specific environment. If I lived in NM it's dusty and would require more frequent. I just feel the one size fits all is to basic for such a advanced and programmable thermostat.
