HVAC Filters do Important Work; Don’t Take Them for Granted
Hardly anything’s as easy to take for granted as the air filter in your forced-air heating and cooling system. But that’s a mistake, since your furnace or AC filter serves an essential function in the operation of that system.
Not changing a dirty filter could shorten the life of your equipment, or lead to a preventable heater or ac repair cost. Yet many homeowners either forget to check their HVAC filter regularly, or else aren’t sure how often the filter should be replaced (or cleaned in the case of a non-replaceable filter).
So just how often should your furnace or AC filter be checked? That depends on several factors, though a monthly check is the usual guideline, absent any other significant factors.
How air filters work
First, though, it may help to understand how the air filter functions in a typical central, forced-air heating or cooling system. An air filter that’s doing its job and is sufficiently high efficiency not only improves indoor air quality by filtering out the majority of airborne particulates, (including unwanted contaminants such as pet dander, allergens, mold spores, bacteria, etc.).
It also will protect sensitive mechanical components in your system from grime and dirt that create friction, hasten breakdowns, and erode the efficiency of the equipment.
As you probably know if you’ve stood in front of the array of HVAC filters on display at a typical big-box home improvement store, they come in a wide variety of sizes and efficiency levels. To confuse things even more, some air filter manufacturers use entirely different rating systems for efficiency, making it very difficult to compare one product to another.
The lowest-quality filters are easy enough to detect, however – they’re a flat panel, with the thin, almost translucent filtration medium surrounded by a cheap cardboard frame. These filters – often found in supermarket chains – only remove the largest particulates floating in your home’s air.
Fortunately, for just a few dollars more, you can select a mid-efficiency filter that will remove the vast majority of airborne contaminants.
At the top of the line are relatively costly high-efficiency filters, but in many cases, these are not recommended for residential forced-air heating and cooling systems. Their filtration media is so thick and dense that airflow may be constrained, forcing a furnace or AC blower to work all the harder to circulate air in your home. (An HVAC system likely can be retrofitted to work with high-efficiency filtration, though that could be costly.)
When should you check or change the air filter?
Most Cincinnati HVAC companies recommend checking the air filter once a month. It’s a simple enough task that a monthly inspection shouldn’t crimp your lifestyle. Figure out a way to remind yourself that it’s time to check the filter.
- Some people program a reminder into their smartphone or laptop,
- while others include the monthly air filter check on reminder lists for bills and what-not.
When you do replace the filter, write the date on the frame of the new filter, so you can always tell how long it’s been operating in your HVAC system.
How to check your air filter
When it’s time for the air filter check, pull it out, and if the filtration membrane is so coated in dust and debris that you can hardly see a light shining on the other side, it’s time for a new filter. And really, even if you replace a filter too early in its life span, it’s not a costly error, and is much better for your system and household than making the opposite mistake: waiting too long.
During fall or spring, or in areas with mild climates, the air filter won’t get clogged or dirty as soon as it would otherwise. It doesn’t attract as much dust and debris as when the equipment is operating all or most of the time.
- For example, a furnace filter in northern Florida might only need to be changed once per heating season.
- Or a filter for an air conditioner operating in northern Michigan might be good for three or four months. But check it monthly anyway – it only takes a minute.
The frequency of needed air filter changes in the home also can be affected by other factors, including the amount of dust, allergens, construction debris and other airborne materials in and around your home.
- If you live on a dirty road,
- the pollen is particularly bad in your neighborhood,
- you have a home improvement project under way,
- or any of a number of other factors
can influence how often an HVAC filter needs to be replaced.