When working in the HVAC industry, we often hear the same questions over and over again. One of those questions we hear repeatedly is how often should you change your AC air filter in your home.
It will come as no surprise that a lot of faults are caused by insufficient maintenance of an air conditioner’s key components. The air filters especially can often go overlooked until it is too late and they are thick with debris and dust.
Without these air filters, these particles would get into the cylinders and pistons which would cause severe damage to your AC unit.
To combat this and save you any costly repairs we are trying to encourage people to make that all-important air filter change more regularly.
We have put together a list of when to change your filter depending on your particular environment and what other variables you should take into consideration that may affect the lifespan of your air filters.
How often should we be changing our air conditioner air filters for home environments?
On the whole, the average home should have its AC air filter changed quarterly (every 90 days). Unfortunately, it’s not as simple as that.
There are many other factors that could result in the air filter becoming blocked more quickly and vice versa, read on to find out more.
A key factor, for any environment but it’s easier to answer when we’re considering home environments, is how many people live in that home and are present on a regular basis?
It’s simple maths when you think about, the more people producing dust and using the air in a certain space, the more frequently AC air filters will need to be replaced.
It’s harder for businesses to do this maths as visitor numbers may fluctuate and so may staff numbers. But in a home, we generally know how many people to expect on a day to day basis. It isn’t just about how many people are there either, it’s the length of time they spend in the home.
For example, a couple who spend from 7:30 am until 6 pm out of the house every day because they are working from another office will not require as frequent air filter changes as a couple who both work from home.
Alternatively, if the home is only used for short periods of times during certain seasons (a summer holiday home or a second home), the AC air filters could be changed as infrequently as on an annual basis.
What other factors can affect an air conditioning filter?
A big one and an often overlooked subject is the presence of pets. Just because they don’t actively acknowledge the benefits of air conditioning doesn’t mean they’re not using it! The hairier the pet, the more likely that air filter is going to need a change.
The presence of a dog or a cat could lessen your filters’ lifespan by about 1 month, resulting in a required air filter change every 60 days. If you have multiple pets or a really hairy Alaskan malamute, you may be looking at a filter change as often as every 20-40 days.
Similarly to pets, smokers will decrease the lifespan of an air filter and result in a build-up of smoking byproduct that will clog your filter.
Other than pets and smokers, the air quality and level of air pollution inside and outside the home (that may enter in when doors are opened etc) will play a huge role in how long your air filter can last. For example, homes in cities will require more frequent air filter changes than those in the countryside.
What about allergies?
It has become common knowledge that if you or anybody in your home suffers from allergies that the air filters in your home need to be changed more frequently. The recommended time is between 20-45 days, but why is this?
If a particular allergen is in the air inside or around your home it isn’t going to just disappear. A common misconception is that the filter will simply ‘filter’ out the allergens – removing them from your environment. Alas, it’s not as easy as that!
If your air filters are not changed regularly, all that is actually happening is the allergens are getting trapped and then stored in the filters within your home. With these particles just sitting in your unit, you’re potentially making allergy season a lot harder for yourself.
Alternatively, paper filters are not designed to trap anything as small as pollen or other allergens. Whilst the paper filters may trap the dust and debris, the allergens are actually just being circulated around your house.
It is important to remember that regular filters are not there to protect you from your allergies, they are there to protect the equipment. What do we advise?
You can invest in HVAC HEPA air filters to help combat your allergies or you can just change your regular filters more frequently. It is important to note, that even with HEPA air filters, you will still be required to make a change every 60 days.
What to look for
Throughout this article, we have focused on when your filter needs changing in hypothetical scenarios but no matter how many of these we give you, no story will be the same.
Here is a list of warning signs that your HVAC air filter may be requiring a change:
- Noticeable dirt/dust build up
- Grey colouring on the filter
- Your home is getting dustier quicker than usual
- The system is not running as efficiently and is taking longer to heat up or cool down
- You’ve had your filter in longer than the manufacturer’s recommendation (check the packaging for this!)
Not all AC filters are the same
If you find your filters are not lasting as long as you’d expect or in comparison to what we have recommended throughout this article, it is important to look at what you’re spending and which air filters you are investing in.
You get what you pay for in the world of air filters and air conditioning in general. Cheaper filters may look the same but they might not be doing the same work.
The packaging will give you an idea of how long the manufacturer thinks the filters will last. It is suggesting frequent changes, it is likely that the filter is not particularly efficient or cost effective.
It is also worth remembering that if you use your system more in certain months (winter/summer) you may notice your filters becoming clogged quicker than you expect. Just remember to keep your eye on it and you’ll soon reap the rewards of a healthy HVAC system.
Is it really that important?
The short answer is YES. If you want a system that is going to cost you less in the long term, with a long engine life, whilst being more efficient both with fuel and emissions then you want to ensure you are changing those filters regularly.
It may take a year or so before you work out how often your filters need changing and it’s more important than anything to remember there is no written rule on how your filter lasts when there are so many variables affecting it in your home.
If you have any questions, remember the air conditioning specialists are always able to help!