Replace or clean filters on furnace, air conditioner, and heat recovery ventilator as necessary
Why
Blowing air through a dirty filter is a lot more work, and takes a lot more electricity than blowing air through a clean filter. If your filter gets dirty enough, it can bend, allowing the air (and dust) to flow around the filter instead of through it.
How
Create a monthly reminder to check filters on furnace, air conditioner and heat recovery ventilator and replace or clean as necessary.