What is a Merv Rating?
Well, I found out what a Merv Rating is today. Turns out it’s pretty important when it comes to your indoor air quality.
I wanted to replace the filter in our furnace and start from scratch. It turns out our house has an electric furnace but it also has an air quality system installed next to it. It’s a system called Aprilaire and it adjusts the humidity levels in the home as well as the indoor air quality.
Most homes have a filter on their air return or in the furnace or heat pump. The system in our house is attached to the outside and it has a rather large filter on it. Another duct has been cut into the outgoing air to allow for moisture to be added during the dry winter months.
No matter what type of system you have in your home, it’s important to inspect and change your indoor air filters on a regular basis. If your filter is clean, it allows more air to travel through it. Your system won’t have to work quite so hard to push that air through, which means you’ll save on your electric or gas bill.
While purchasing the replacement filters for the house, I noticed they had individual “Merv Ratings” on them. I had no idea what a Merv rating was. So… I looked it up.
Turns out that the Merv rating refers to how effective the filter is at removing dust and microns from the air. The higher the number, the more effective the filter is. They go from one to sixteen. When the rating is higher, the filter can help remove some or all of dust, pet dander, pollen, and even smoke if it’s rated high enough.
Most of the typical flat filters found in a house are rated from about 1 to 4. They have a thin membrane of filtration that barely stops larger pieces of dust or debris floating through your house.
If at all possible, see if you can find a larger filter that will still fit your system. The more filtration you have, and the larger and more pleats it has, the better the air and the longer it will last. That means less recycling and better air quality.
One side effect of using a furnace or air filter is that it also keeps dust off the appliances heating and cooling coils. When those coils are dirty, there is also a drop in efficiency as they have to work harder to keep the air warm or cool.
When to Change the Filters?
If you have the flat filters that are usually less than an inch thick, you should replace them every month. It depends on how many people live in your house and whether or not you have a pet. Check the filter on a regular basis to make sure it’s not clogged, damaged, or wet.
If the filter is hard to see through, looks very gray, or has any holes in it - replace it. Your air will improve and your system will run better (saving you money and allow you to use less energy.)
