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Winter is still upon us here in Indy and it’s getting colder (and more unpredictable) every day. That’s why you need to make sure your furnace filter is clean, so when you need to turn up the heat you’ll get the warmth you need quickly.


A common homeowner misconception is that the furnace filter is there to help clean the air inside your home. Even though the filter may help with the quality of air, it’s main job is to protect the furnace blower from any dust, pet hair, etc. that’s brought in. In fact, if your filter isn’t being cleaned as often as recommended it could lead to the air flow being blocked altogether which can quickly damage the whole unit.


So how often do you need to change and/or clean your air filter? The average recommendation is every 90 days. Regardless of the size of the filter, you still want to check it every 3 months to make sure it is running smoothly and not blocked.


The hardest part of changing a filter is to make sure you know which one to get. There’s essentially three things you need to know: the filter size, MERV rating, and what specific kind of filter to get.


Filter Sizes

When purchasing a filter, you always want to make sure you have the right measurements. No one wants to make another trip back to the store. Typically a filter size is measured by height, length, and thickness. The average thickness is a 1” for most units and 4” for larger ones. The safest bet is to take a picture or write down the measurements that your old filter has which should be written on the frame. 



Furnace filters are rated on 1-16 MERV (minimum efficiency reporting value) scale. The higher the number the more particles the filter can remove, which also makes the cost go up. An issue the MERV rating may have if it is too high is you may get less airflow causing your furnaces to work harder.


An average safe MERV rating is 8-11. Be sure to check your manufacture’s maximum rating.


Pleated Vs. Permanent

Pleated filters are disposable filters made from paper. They come in many sizes and do the job when filtering household particles.


Another option is a permanent reusable filter. The plastic or sometimes aluminum frame is great if you have a hard time remembering to change filters in the first place. These filters last up to 5 years. However, they do still need cleaned every quarter. You can clean them fairly easy with a vacuum cleaner or wash rag.


Note: Both filters come with an electrostatic option. This self-charge version helps if you have smokers or pets in the home. You will need to check with your manual first to be certain your furnace can work safely with an electrostatic filter.



Now that you have your filter, it’s time for the easiest and most satisfying part: installing.

*If you have a reusable instead of replacing the filter, simply vacuum the sides and wash off excess dirt and dust.


First, you need to turn off your furnace and then find the filter compartment door which is between the air intake and furnace. After you open the compartment, slide the old filter out. It will be pretty dusty so take caution. 


Next, find the arrow printed on the frame of the new filter. The arrow points to the direction of the airflow, so the arrow needs to face the furnace side when sliding it into place.


Lastly, shut the compartment and turn the furnace back on.


Just like that you are done! Now, the next time you change it you’ll know exactly what to do.



For more Home and Garden tips, tune in to the Home and Garden show every Saturday right here on WIBC or send us a message on facebook.