1. Purchase a better filter if you haven’t already. The new high-efficiency pleated filters have an electrostatic charge which works similarly a magnet to grab the tiniest particles — even those that carry bacteria.
2. Replace the filter at least every three months. But check it once-a-month. If it looks clogged & dark, go ahead and change it. In case you have pets, you’ll possibly need to change every month.
3. Check there are at least two feet of clearance around outdoor air conditioning units and heat pumps.
4. Remove debris, such as pollen, leaves, and twigs every 7 days, during summer, spring, and fall from top and sides of outdoor air-conditioning units and heat pumps. Don’t permit the lawn mower to discharge grass clippings onto the unit.
5. Every 30 days, inspect insulation on refrigerant lines leading into the house. Replace if missing or damaged.
6. Confirm unit is level. Annually, confirm that outdoor air-conditioning units and heat pumps are on firm and level ground or pads.
7. Stave off clogs. Annually, pour a cup of bleach mixed with water down the air-conditioner condensate gutter to avoid buildup of mold and algae, which can cause a clog.
8. Shut down the water source to the furnace humidifier in summer. In fall (or when you anticipate turning on the heat), swap the humidifier wick filter, set the humidistat to between 35% and 40% relative humidity, and turn on the water supply.
9. Never lose more than 20% of a home’s registers to avoid placing unnecessary strain on the HVAC system.
10. Change the battery in your home’s carbon monoxide detector yearly.