Filters are essential in ensuring the air your furnace blows out is free of dirt, dust and other air contamination. Clean filters are key to your furnace running efficiently and your energy bills staying low.
Due to the role they play in trapping dust and airborne particles, filters will eventually accumulate dirt and grime. That means they will need to be replaced at some point. Here are some of the most important factors you need to take into consideration as you contemplate replacing the filter on your furnace.
1. Replacement Frequency
There is no universal rule on how frequently you should replace your filters. A common practice is to get new filters every 90 days. However, experts such as those at furnace-repair-toronto.ca insist you should be ready to replace them within a shorter time frame depending on the quality of air in your home or neighborhood.
The air quality index is not a static figure, so you should be prepared to vary the filter replacement frequency depending on the average air quality within a given period of time. Replacement frequency also depends on the type of filter you are using and the air-impacting activities taking place within and around your home.
2. Telltale Signs
Two houses in the same neighborhood will not necessarily need to replace their furnace filters at the same frequency. To get it right, keep an eye on telltale signs that your filter is getting overwhelmed by an unusually high amount of dirt or dust.
One clue would be to check how soon your furniture gets coated with dust. If you have to clean dust off your tables after just a day or two, your furnace filter is likely struggling to discharge clean air. This will be confirmed when you take a peek at the filter and find a dust-laden discoloration or a grayish color.
3. Dense Filters
Furnace filters usually have a minimum efficiency returning value (MERV) ranging between one and 16. For residential use, the recommended MERV rating is six to 12. Filters with MERV below six do not block airborne particles effectively while those above 12 are meant for hospitals, labs and similar environments.
A filter with MERV approaching 12 would seem the best option for home use, since it has the capacity to block microscopic pathogens. But such capability comes at a price – these filters become clogged more quickly and therefore require more regular cleaning or replacing.
4. Furnace Usage
If you live in a warmer area, you will not be running your furnace during the winter as much as someone in a colder climate would. In that case, the 90-day replacement cycle will work, if all other factors remain constant. If you are in a region that has freezing winters and frigid temperatures, your furnace must work harder. In that case, you may need to change the filter every 30 to 60 days.
5. Furnace Fan Setting
If you set your furnace’s fan setting on the thermostat to “on,” your fan will be running constantly. That means the filter will be collecting contaminants 24 hours a day, which results in a dirtier filter more quickly. This is as opposed to placing the fan in the auto setting that would mean the fan only turns during the heating phase.
6. Location of Return Vents
The location of your furnace’s return vents can determine how quickly your filters accumulate dirt. If the vents are near a source of dust and dirt, these air contaminants will be sucked in and contribute to the rapid buildup of the filters. Keep the areas around your return vents clean to ensure the air sucked in is relatively clean.
7. Flat Versus Pleated Filters
There are two main types of furnace filters – pleated and flat. Pleated filters tend to clog more slowly than flat filters do. A pleated filter has a larger surface area and can therefore accommodate more dust before it needs changing. For this reason, a flat filter needs to be changed more frequently than a pleated one.
A pleated filter can last as long as 90 days while a flat one may need to be replaced every 30 days.
Your Furnace Depends On It
The efficiency and lifespan of your furnace is directly dependent on the timely replacement of its filters. Take these factors into consideration and your furnace is likely to run more efficiently for longer.