Attached is an article I found recently that describes very well just how important it is to change out your home HVAC air filters on a routine basis. You may not agree with all the points the author proposes but the main take away is just how important these seemingly inexpensive items are to our health and utility costs.
Why you must change your air filters…every month!
Mark, our energy auditor, recently did an audit on a fairly new, 3500 square foot house, whose owners reported unusually high energy costs. He did the audit and found that the house was pretty tight – HVAC ducts had fewer leaks than normal, and the attic was tight, as was the rest of the home’s envelope. There was no reason for their bills to be so high…except that they hadn’t changed their air filters since they moved in, a year and a half ago.
Because the air filters were clogged the HVAC system had to work extra hard to get any conditioned air into the home. In fact, the first thing he noticed before he even began testing the home for leaks is that a lot of noise was coming from the air returns. He could literally hear the resistance of the air getting into and out of the home.
Most homes will have energy inefficiencies above and beyond something so simple as dirty air filters, but it’s worth emphasizing that this is an important part of energy efficiency in the home – changing out your air filters is cheap, simple, and can have big impact on energy use and air quality.
There are basically three kinds of air filters available on the market right now: reusable, washable filters; pleated filters that block a lot of air but trap more particles – often advertised as helping people with allergies; and thin, less expensive, fiberglass or polyfil filters.
You would think that since we have a green business we’d tell you to get the reusable filters – but you’d be wrong! Although we are all for reusing, reducing, and recycling, in this case there are a couple of reasons not to use the reusable air filters. First, for them to be effective you need to clean them every single month. For many people this won’t be an issue, but for those who aren’t systematic about things like this the particle build-up on the reusable filters if they’re not cleaned every month can cause your HVAC system to work harder than it should, and it could be a health and safety hazard, depending on how long you let it go on.
Second, when you wash them they need to be 100% dry before you put them back or you could be spreading mold and mildew throughout your home, which is the opposite of what these filters are supposed to do. Washing them also doesn’t get rid of all the contaminants – obviously defeating the purpose of air filters once again.
For most people, too, we don’t advise the pleated filters, largely because most homes’ HVAC duct systems are designed using lots of flex ducts, which forces the HVAC unit to work hard to push air through. Add a pleated filter to this situation and the HVAC unit’s life can be shortened.
If you have a lot of allergies and you want to use the pleated filters, you should talk to an HVAC technician to see if your home’s ductwork will work with these filters. You may have to have your ductwork redesigned so that the filters can be effective.
So what’s left? The cheap fiberglass or polyfil filters (purchased through a HVAC supply company, like C.C. Dixon) are what we recommend. They are inexpensive, provide good filtration, but not too good (thus blocking air flow and causing your HVAC system to work hard), and work with all homes’ HVAC systems.
The downside is, of course, that they’re disposable, not biodegradable, and thus add to our trash problem. As someone who composts and recycles everything she can, I have a problem with basic wastefulness – but at the same time, there’s no really good alternatives on the market right now. It’d be great if someone came up with a biodegradable air filter – we’ll be happy to test this product when it comes on the market – but for now we have to stick with recommending old school air filters…as long as you remember to change them!
Because the air filters were clogged the HVAC system had to work extra hard to get any conditioned air into the home. In fact, the first thing he noticed before he even began testing the home for leaks is that a lot of noise was coming from the air returns. He could literally hear the resistance of the air getting into and out of the home.
Most homes will have energy inefficiencies above and beyond something so simple as dirty air filters, but it’s worth emphasizing that this is an important part of energy efficiency in the home – changing out your air filters is cheap, simple, and can have big impact on energy use and air quality.
There are basically three kinds of air filters available on the market right now: reusable, washable filters; pleated filters that block a lot of air but trap more particles – often advertised as helping people with allergies; and thin, less expensive, fiberglass or polyfil filters.
You would think that since we have a green business we’d tell you to get the reusable filters – but you’d be wrong! Although we are all for reusing, reducing, and recycling, in this case there are a couple of reasons not to use the reusable air filters. First, for them to be effective you need to clean them every single month. For many people this won’t be an issue, but for those who aren’t systematic about things like this the particle build-up on the reusable filters if they’re not cleaned every month can cause your HVAC system to work harder than it should, and it could be a health and safety hazard, depending on how long you let it go on.
Second, when you wash them they need to be 100% dry before you put them back or you could be spreading mold and mildew throughout your home, which is the opposite of what these filters are supposed to do. Washing them also doesn’t get rid of all the contaminants – obviously defeating the purpose of air filters once again.
For most people, too, we don’t advise the pleated filters, largely because most homes’ HVAC duct systems are designed using lots of flex ducts, which forces the HVAC unit to work hard to push air through. Add a pleated filter to this situation and the HVAC unit’s life can be shortened.
If you have a lot of allergies and you want to use the pleated filters, you should talk to an HVAC technician to see if your home’s ductwork will work with these filters. You may have to have your ductwork redesigned so that the filters can be effective.
So what’s left? The cheap fiberglass or polyfil filters (purchased through a HVAC supply company, like C.C. Dixon) are what we recommend. They are inexpensive, provide good filtration, but not too good (thus blocking air flow and causing your HVAC system to work hard), and work with all homes’ HVAC systems.
The downside is, of course, that they’re disposable, not biodegradable, and thus add to our trash problem. As someone who composts and recycles everything she can, I have a problem with basic wastefulness – but at the same time, there’s no really good alternatives on the market right now. It’d be great if someone came up with a biodegradable air filter – we’ll be happy to test this product when it comes on the market – but for now we have to stick with recommending old school air filters…as long as you remember to change them!
