It's easy to forget about your furnace filter, but it's an important part of keeping your home comfortable and healthy. The basic consensus among HVAC professionals is that you should replace your furnace filter every 90 days or every three months. However, this depends on the thickness of the filter. Thicker filters have more room to pick up dirt and dust, so they don't need to be changed as often.
Thomas & Galbraith Heating, Cooling and Plumbing of Ohio recommends replacing filters that are less than 2 inches thick every 30 to 90 days. Three- or 4-inch filters can last 6 to 9 months, and filters up to 6 inches thick can be replaced once a year. If you are allergic to dust or pet dander, you should change your air filters more regularly than every 90 days. Try replacing filters after 60 days and, if your allergies continue to increase, consider changing them every month or changing them to pleated filters. For 3- and 4-inch filters, plan a replacement approximately every six to nine months.
If you have larger 5- or 6-inch filters, you'll need to change them every nine to 12 months. Regularly replacing your furnace filter will help your HVAC system last longer, but knowing when to change it can be confusing. Let's go through the basics of your furnace filter and determine exactly how often you need to change it. However, if your HVAC has a single filtration system that uses an air filter for the conditioning unit and furnace, replacements will be less frequent in winter than in summer. Learning to choose between the different types of furnace filters can help keep your home cozy and your air fresh and clean for years to come. Changing your furnace filter regularly ensures that the air in your home remains free of dust and other contaminants.
Considering the factors that influence the air quality inside your home is a good measure of how often furnace filters need to be replaced. When you remove the air filter from the air handling unit, if you hold it close to a light source, you can see if the filter is dirty or clogged; if you can't see the light through the filter, it's definitely time to change it. Marking your calendar every 90 days or trying to remember the last time you changed your filter can be a challenge, which is why many furnace manufacturers recommend replacing it at the beginning of each new season. In general terms, HVAC furnace filters do not need to be changed as frequently during the winter months compared to the summer months. However, the smaller the appliance used for cooling, the small space usually comes with smaller filters, so you may need to change the filter as often as a filter in a larger home.
To help solve this conundrum, here is some information on how often you should change your furnace filter. Filters receive a minimum efficiency report value (MERV), ranging from 1 to 16, although ratings 6 to 12 are best for residential furnaces. Even though almost everyone knows about furnace filters, they are still one of the most neglected HVAC maintenance tasks. There are two different types of furnace filters, and the one in your furnace will determine how often it needs to be changed. If you live in a mild climate and only use your air conditioner or heater for a few hours a day, a filter could last the entire season or up to an entire year.
Because of their pleats, filters such as the Honeywell Ultra Efficiency Filter (also available on Amazon) have more square inches of space to trap dust, so they often require fewer changes - usually every 90 days.