Guides / Inside the house
HVAC and indoor air
Heating and cooling systems are among the most expensive things in a house to replace, and they work harder when neglected. A few simple habits extend their life and improve the air you breathe.
What to check
- Filters
- Check the filter monthly and replace it when dirty. Depending on the filter and your household, that is often every one to three months.
- Outdoor unit
- Keep a couple of feet clear around the condenser. Remove leaves and cut back plants so air can flow.
- Vents and returns
- Make sure furniture and rugs are not blocking supply vents or return grilles.
- Condensate line
- In cooling season, check that the condensate line drains and the drain pan under the indoor unit is dry.
- Humidity
- Indoor relative humidity in roughly the 30 to 50 percent range is a common target. A cheap hygrometer tells you where you are.
- Thermostat
- Replace thermostat batteries yearly if it uses them, and review the schedule when seasons change.
When to do it
Service heating in early fall and cooling in spring, before the busy season.
Call a licensed professional for
- Annual service for furnaces, heat pumps and air conditioners
- Any gas smell, scorched smell, or a system that cycles on and off rapidly
- Refrigerant issues, which require a licensed technician
This guide is general information for US homeowners. Codes, climates and houses vary. It is not a substitute for an inspection or advice from a licensed contractor, and in an emergency call 911.