The biggest reason that HVAC systems fail is a dirty air filter. The dirty filter compromises the HVAC air flow, which in turn places extra strain on the air handler fan motor. Over time, this strain can burn out the motor, resulting in overheating and ultimately, failure. Replacing an air filter is significantly less than the expenses that you will incur if your system fails.
The general rule of thumb is to change standard 1-inch to 3-inch air filters every 30 to 60 days. However, you may want to adjust this schedule based on the following guidelines:
- Typical suburban home with no pets: 90 days
- A single cat or dog: 60 days
- Multiple pets and/or allergies: 30 to 45 days
- Vacation home or single occupant home with no allergies or pets: 6 to 12 months
Furnace and AC Filters
Air filtration is integral for effective heating and cooling. A filter keeps a system clean, which in turn maintains optimal efficiency. When you run a furnace without an air filter, you can incur expensive repairs, high utility bills, reduced equipment lifespan, and an uncomfortable air level in the home.
It is recommended that you change a furnace filter every month or two months. Check your old filter to determine which filter to buy. It should have the dimensions clearly labeled. If you have your furnace manual, it may also include this information. Before you switch on the furnace during the cold months, install a new filter. If you have dust allergies or the furnace smells or look dusty, consider having a professional service brush and vacuum the ducts.
Dirty filters significantly compromise an air-conditioner's efficiency. Install a new one once a month during the warm months when you run the window or central air units on a regular basis. Alternatively, if you have filters that are washable, wash them instead of replacing them. When you purchase a filter, check the efficiency reporting value or MERV. This figure is in the range of 1 to 12 for home air-conditioner units. Higher numbers indicate better filtration and increased energy requirement.