Feb 26 2017

replacing air filter

Your HVAC air filters keep the air in your Montgomery, Alabama, home clean. Think about how your air filter choice affects your lifestyle. After all, the air filter is standing between you and breathing in bad indoor air.

What Is MERV Rating?

MERV stands for Minimum Efficiency Reporting Value, and it tells you how effective an air filter is at blocking particles and debris from entering your HVAC system. The higher the MERV rating, the better the filter is, and the smaller particles it can filter.

MERV ratings range from one to 20. A MERV rating of one will only remove the biggest dust particles and doesn’t do much to help your IAQ. MERV 20 is usually only found in medical settings where the air needs to be extremely clean. Most residential HVAC systems can’t handle a MERV 20 filter and need to work extra hard to push the air through it. Typically, you can go as high as MERV 13 without stressing your system too much, but we’re happy to answer questions about that next time we come to do HVAC maintenance.

Do Any Other Rating Systems Exist?

When you go to Home Depot or Lowe’s, you might see air filter brands that use their own rating system. Those brands could give you a number from one to 10, or list all the things the air filters capture from your indoor air. Check the packaging, because the MERV rating will be on there somewhere. It might be hidden on the back in a small font, but you’ll be able to find it. Use the MERV rating to decide which filters are best, no matter what the other parts of the packaging say.

Where Do You Install the Filter?

Your air filters go in your return vents. Most homes have between one and three return vents, but depending on your square footage, you might have more. Uncommonly, air filters go in the HVAC system itself, but your house probably has return vents that need filters.

If you don’t know which vents are your return vents, pay attention next time your HVAC system is on. The return vents will not be blowing air out. If you put your hand very close, you might be able to feel them sucking air through instead.

The metal grate comes off the front of the return vent, and the air filter fits inside. If you already have a filter in there, it’ll tell you what size you need. If you don’t, just get out the tape measure. Air filters are available in lots of sizes. Most of them are one inch thick. We can help you figure out if you need a thicker filter.

Are Washable Filters Worth It?

Most washable filters are electrostatic filters, which means they use static electricity to attract and trap particles on the filter. Some homeowners prefer washable filters because they’re a more environmentally friendly option. Your washable filter will last several years before you need to buy a replacement. You hose it off as often as it needs, let it dry, and replace it.

The main concern with washable filters is their electrostatic nature. Electrostatic alone isn’t enough to trap the tiny particulates that aggravate asthma symptoms and allergies. When you want a very high MERV rating, a washable filter probably won’t be available. If you’re very busy, you might not want the chore of washing off your filter. It’s fine to prefer to simply pull out the old one and stick in the new one! You have to choose the filter that fits with your lifestyle best.

Now you can buy disposable filters with electrostatic charges, too. An electrostatic charge doesn’t hurt and can help keep the particles sticking to the filter once they’ve been trapped. Electrostatic by itself, though, isn’t enough for your air filter. You should only look for it in conjunction with a high MERV rating.

Change your filter at least once every three months, and preferably more often. If you have any air filter questions or need HVAC maintenance, Air Conditioning by Luquire is your resource. Call us at 334-230-5870.

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