It depends on the blower design. If it is a constant rpm fan, it will draw less power and flow less air when the filter is dirty. If it is a variable speed fan with a CFM sensor, the fan should speed up to get the air flow where it needs to be. So in the latter case, the fan will draw more power with a dirty filter. But this design typically has controls to limit the fan power so it doesn't burn up the fan motor. It will only go so fast and may indicate it is at max power usage.
Actually having a clogged air filter forces the system to work harder, and it can indeed damage the system or shorten its life. More resistance = more energy expended. HVAC techs will tell you the same, and the physics backs it up.
Might not be too noticeable, but forcing the motor to run more every day to push the air enough to raise or lower the temp will have a measurable effect eventually.
Statistics: Posted by suemarkp — Fri Nov 22, 2024 2:50 am