Article Summary:
Forced air systems require regular filter changes to keep the system running efficiently. Here we cover what kinds of filters are available and a few DIY tips.
If you have a forced air system, you’ll typically need to change your air filter once or twice a year to keep your heating, cooling and fan systems running smoothly. With Filter Reminders, the Nest Learning Thermostat will let you know when it’s time to change your filter based on how long your system has been running.
Learn more about setting up Filter Reminders on the Nest Thermostat
You can contact a professional to change your filter for you, or do it yourself. It’s usually a quick DIY job that shouldn’t take you more than 10 min.
Where is my filter located?
Your filter can be located anywhere between the furnace and the vents where warm or cool air enters the room. Common locations include inside the ductwork, behind vents, or in the air handler itself.
What filter size do I need?
If you’d like to replace your filter yourself, here’s how to figure out the filter size you need.
- Most furnace filters have two sets of dimensions: nominal and actual. If you measure your filter and it’s actually 15½" x 24¾" x ¾", you would round up and search based on the nominal dimensions of 16" x 25" x 1" (or, if your filter was 39.4 cm x 62.8 cm x 1.9 cm, you’d round up to 40 cm x 63 cm x 2 cm).
- If the nominal size isn’t printed on your old filter, just measure your filter’s width, length and thickness. Round up and you’ll get the nominal size.
- You want your filter to fit snugly without having to force it into place. If it’s too loose and you feel air leaking around the filter, add some furnace filter gasket tape around the edges.
What kind of filter should I choose?
What kind of filter you should get depends on what you need - you can get everything from a less expensive filter that will filter 15-20% of particulate matter to high-end air purifiers that can take up to 90% of particulate matter. Many filters are disposable, while some can be reused. If you have a reusable filter, it will need to be cleaned instead of replaced.
MERV (Minimum Efficiency Reporting Value) is the rating for filter efficiency. Filters go from MERV 1-16, with 16 being the most effective and expensive. High end filters toward the top of the MERV scale are particularly good for people with allergies and respiratory issues, however they use slightly more energy (since it takes more power to push air through a high-efficiency filter than a low-efficiency one).
For more information about the best filter for your system, contact your local HVAC professional. He or she will be able to suggest a model for your heating system.