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The Complete Guide to Furnace Filters

If there’s one piece of advice we could give customers to keep their home furnaces working all winter long, it’s to stay on top of the air filter. This is one of the simplest components of an HVAC system – but also one of the most important.

Not sure what the air filter does or how to replace it? Don’t worry – we’ve put together this complete air filter guide to help you maintain your furnace.

Do all furnaces have filters? Yes, every furnace should have a filter. You can find the filter in between the return air duct and the main furnace unit.

What does the furnace filter do? As air is circulated through the HVAC system to the furnace, it picks up dust, dirt, pet hair, pollen, and other debris. The purpose of the filter is to catch these contaminants before they enter the furnace. This protects the unit and improves air quality home as the furnace blows hot air around the home.

How often should the furnace filter be replaced? Over time, debris collects and can clog the filter. This reduces the airflow, which can damage the furnace and cause performance issues (like your house being too cold). Thankfully, the easy solution is to insert a fresh, new filter on a regular schedule. For most furnaces, it’s a good idea to replace the filter every 1-3 months. This can be affected by a number of factors including the type of filter you use, having pets, or whether there’s anyone with allergies or a respiratory medical condition in the home. Since air filters are relatively inexpensive, you’re better off replacing it too soon rather than too late.

How to select the right replacement furnace filter

Size – It’s important that the filter is the correct size for the filter cabinet so it catches all of the air going to the furnace. Check the old filter – the size should be printed along the edge. Common sizes are 16×20 inches, 16×25 inches, and 20×25 inches.

Thickness – After finding the right height and width dimensions, determine how thick of a furnace filter you want. In general, the thicker the filter, the longer it will last. But you also have to make sure it will properly fit into the filter cabinet.

Efficiency – There is a numeric range for filters that tells you how effective it is at catching extremely small particles in the air. This is called the MERV system. Normal households can typically use a filter with a 10 MERV rating, while those with pets or specific needs may want to go up to 12. Keep in mind that filters with higher MERV numbers may be more expensive and may need to be replaced more frequently.

Pleated or non-pleated – We recommend using a pleated filter, which has folds like an accordion to increase the surface area. This makes the filter more effective and helps it last longer. Non-pleated, or flat filters, will need to be replaced sooner.

How to install a new furnace filter

The good news is that it’s very easy to replace a furnace filter. First, find the filter cabinet and pull out the old filter. The most important step is to line up on the arrow on the new filter so that it points toward the furnace. This indicates the direction of the airflow. Insert the new filter, close up the cabinet, and you’re done.

When you contact an HVAC professional Replacing the air filter is an easy task and one of the best ways to keep your furnace working at peak efficiency. If you run into any other issue with your furnace this winter, don’t hesitate to contact the team at DeZiel Heating & AC. We’ve been providing trustworthy service to West Metro, Wright County, and Buffalo area since 1997. Call us today at (763) 200-5453 .

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