Can you stack HVAC filters?

Can You Stack Air Filters? Do not stack multiple smaller air filters on top of one another to fit them into a larger air handler. Installing multiple 1” air filters in a 2” slot, for example, can cause costly damage to your AC unit, as residential furnaces are not equipped to handle this level of airflow restriction.

Can you use two air filters?





Bottom Line: Putting two air filters on a central air system will only have the net effect of producing a higher utility bill and reducing the lifespan of your central air unit. In short, the use of two air filters is just a BAD idea!

Do I need both a furnace filter and a return air grill filter?

Do I Need Both a Furnace Filter and a Return Air Grill Filter? Yes, you are going to need a furnace filter and a return duct filter. The main purpose of the furnace filter is to protect the blower from dust, debris, pet dander, and so on.

Can you layer air filters?

In some cases, your intake vents or air handler vents have a filter depth greater than an inch. Because 1 inch air filters are the most common, some homeowners may think it’s okay to layer 1 inch air filters to fit a 2-, 3-, or 4-inch air filter slot. It’s not recommended to do this.

Does every return vent need a filter?

In general, it is recommended to have an air filter in every return vent (as long as you choose the one of the right size and thickness). The filters will improve the air quality in your house and will protect the HVAC equipment from dust, pollen, pet dander, and hair.

Is a 2 inch filter better than a 1-inch?





Well, the thicker the filter the less restrictive it is. This contributes to a better flow of purified air. This means that 2-inch furnace filters allow a better flow of air than 1-inch filters.

Why do I have two air returns?

Having two air return vents allows you to seasonally control which air is returning to the HVAC system. In older homes, this may not be an option. The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.

Can you use a 1 inch air filter instead of 2?

If your system only fits a 1-inch or 2-inch filter, a high MERV rating could be detrimental. A 1-inch filter with less surface space will get clogged fairly quickly and need to be replaced much sooner than a thicker filter.

Can you put filters on return air vents?

Installed at the return vent in your home, they pre-filter dust and other particles. This keeps your ductwork clean and extends the life of the main filter at your HVAC unit. If you have a standard-sized return vent in your home, it will be able to accommodate a regular, rectangular-shaped air filter.

Are electrostatic furnace filters better?



Electrostatic filters are the clear winner here. Although fiberglass filters are very inexpensive, they are only able to remove large particles from the air. They also offer little to no effect on improving air quality.

How long do electrostatic filters last?

A good rule of thumb is to replace pleated filters every 90 days. If you have electrostatic or washable filters, they should be washed, dried, and re-installed once a month. The washable filters are more eco-friendly and, if cleaned and reused appropriately, can last 5 to 10 years.

Why is my return air vent so dirty?

Here are some of the most common culprits: Your air ducts are leaking. Cracked or damaged air ducts can allow contaminants to enter your system and cause your filter to clog up. They can also significantly increase your energy bills.

How many return vents do I need?



Ideally, every room except the kitchen and bath should have its own return air grille. At the very least, each level of the house should have one. Even so, many homes were built with just one or even no return ducts in an attempt to cut costs.

Do air vent filters restrict airflow?

The biggest drawback of vent filters is restricted airflow. Filters slow the passage of air. As particles build up on them, the amount of obstruction increases. This can cause your system to work harder, using up more power and potentially overheating components.

Are pleated filters bad for HVAC?

Pleated filters are bad for your system because they block too much air, forcing the HVAC motor to work harder to pull in the air it needs and burning it out faster.

Do higher MERV filters restrict airflow?

Wrong. While the highest MERV ratings are the most effective for air quality, they can harm your HVAC system. A higher MERV rating means a higher resistance, which means less airflow.

Do high MERV filters always reduce air flow?



Not always. Many people don’t consider how a filter with a high MERV rating will affect other parts of the HVAC system. The primary concern when upgrading to a higher MERV rated filter is the reduction in airflow in the system.

Is MERV 13 too high for HVAC?

MERV 13 air filters are the highest-rated air filters for home use. Any air filter with a rating higher than 13 will restrict air flow to the point of which could cause damage to your HVAC system, resulting in an added expense to fix it.

Is MERV 12 too high for HVAC?

When in doubt, choose a MERV 8 to MERV 10 filter rated for high airflow, so it won’t damage your furnace or air handler. Or you can ask a certified HVAC technician what filter is best for your furnace or air handler.