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How Do I Know Which Direction to Install My Furnace Filter?

new furnace filter being installedBelieve it or not, there are right and wrong ways to insert an HVAC furnace filter. If a filter is not correctly installed, it could hamper the furnace’s efficiency and cost you money.

It’s essential to routinely monitor your air filters to prevent them from clogging with dirt, dust, or debris so they continue filtering the air you and your family breathe. Clean filters allow for better indoor air quality and improved energy efficiency.

When an air filter is clogged, the furnace has to work harder to do its job. One clue telling you when it’s time to replace filters is when you can no longer see through them. If you are unsure when to change the filter, invest in an electronic air filter monitor that will tell you when it’s time.

Time to Change the Filter

When it’s time to change your filter, follow these tips to ensure it is performed correctly:

  1. Locate the filter. In most furnaces, the filter is adjacent to the furnace and inserted where the ductwork meets the furnace.
  2. Determine where on the furnace you can find the filter air box. Stand in front of the furnace and look for the ducts. Pull the old filter out and discard it.
  3. Find the arrow indicating the proper airflow direction on the new filter. The arrow must face toward the furnace and away from the return duct that pulls the air in need of heating or cooling. It’s smart to draw the airflow direction arrow with a permanent marker on the furnace or ductwork. Label the new filter with the date when you are changing it to help you keep track of how long it’s been between changes.
  4. Slide the new filter in with the arrow pointing toward the furnace.
  5. Replacing your air filter is not difficult. Remember that air flows from your ducts, through the filter, and into the furnace. The arrow on the filter should always point toward the furnace.
  6. The furnace or the filter air box most likely contains the correct filter measurements for replacement filters, or you can just check the filter itself.

Be sure you always have a new air filter on hand so you can change it anytime. Not sure how to choose a furnace filter?

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