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FILTERS FAQ

How Do I Measure My Air Filter?

When you need to replace your air filter, these  steps will help you measure the right dimension for your purchase. Your system is expensive!   Maintaining it will insure it is operating efficiently and maybe you will see less trips by a repairperson.   An affordable air filter purchase is cheaper than a service call.  A new air filter will keep good air quality in your home, increase the life span of your system, and consume less energy – lowering your bills.

We hope that your on-line purchase also is more convenient that you running down to a store.  If you buy a case you will always have a new air filter right by your side.

Your air filters should be changed every 30 to 90 days depending on the type and efficiency of your air filter. However, according to Energy Star (www.energystar.gov),air filters should be changed every month during peak summer and winter months when your HVAC system is operating at highest capacity.

Remember to turn off your HVAC unit before attempting to change the air filter. If you can’t see the shut off switch just turn off the circut breaker.  Be safe!   Can you locate your air filter ???   Most air filters are located to the right or bottom of the unit and should easily pull out of the slot. Some air filters are found in air vents instead. If that is the case, you might need to contact a professional for assistance.   You might want to draw attention to where the filter is with a pice of duct tape and you can mark with a pen what size your unit takes and in which direction the airflow of your unit goes.  Make it easy for everyone in the household to know how to replace them and what the filter numbers are.

To measure your air filter, follow these easy steps:

• Step 1: Measuring Length and Width (L x W). (If your air filter is not a square, the smallest measurement goes first).

• Step 2: Measure Depth (D) – Measure the thickness of your air filter.

• Step 3: Put Your Measurements Together (L x W x D).

• It’s as simple as that! You are now ready to buy the right filter for your AC or Furnace

Can I use the same air filter for both heat and AC?

Yes, both AC filters and furnace filters are the same thing. At Sheridan Supply, we categorize filters based on their intended use to make filter shopping easier for the customer. During the summer months you are more likely to search for AC filters. While during colder winter months you are looking to buy furnace filters. A good tip for remembering when to change your filters is to replace them at the start of each new season.

Which direction does the air filter go?

At Sheridan Supply, we suggest that you point the arrow on the box in the direction of airflow. If you are unsure the direction of airflow turn on the system fan. Do not remove the old filter before checking airflow as this might allow dirt or debris to escape.  Maybe you might want to take a black marker and draw an arrow on your unit for future reference.

What is air filter MERV rating?

The Minimum Efficiency Reporting Value (MERV) is used by manufacturers to explain how efficient the air filter is at trapping airborne particles!   A higher MERV rating means cleaner air but reduced air flow. MERV 8 filters capture 80% of airborne particles like pollen, dust mites, mold spores, and pet dander down to 3 microns in size. MERV 11 air filters capture up to 95% of the above mentioned airborne particles down to 1 micron in size!

If you choose a MERV 13 filter expect greatly diminished airflow but improved filtration of bacteria, tobacco smoke, and cooking oil down to 0.3 micron in size. Before you choose a MERV rating check with your HVAC manufacturer to see what your system is designed to handle. Picking the wrong filter CAN impact air flow and reduce equipment life.

When to change the air filter in your house?

How often are you using your system ?  Are you living in the Northeast or the Southwest ?  Many will suggest that you replace your air filters every 3 months. You may need to replace your filters more frequently depending on air quality. If you are unsure about indoor air quality check the filter monthly. If you see that the filter material is greatly discolored or looking dirty change —-out the filter. If you fail to replace air filters as recommended it might lead to reduced system efficiency, greater energy costs, and poor air quality.  Your system is a big investment !   Be sure that you are maintaining it!

Which air filter is best for allergies?

If you have respiratory problems caused by pollen, dust, mold, or pet dander a MERV 11 filter can help reduce the severity of aliments caused by allergies. If you are sensitive to smoke from cooking or tobacco a MERV 13 filter is recommend. If you or someone in the house is an allergy sufferer it is recommend you install filters to process both supply and return air. Before you choose a MERV rating check with your HVAC manufacturer to see what your system is designed to handle. Picking the wrong filter could impact air flow and reduce equipment life.

Which air filter is best for my home?

We, at Sheridan Supply feel that your choice depends on your needs.  If you have no allergies and no pets, you might want to use a  MERV 8.  MERV 11 filters are recommend for occasional allergy sufferers and homes with pets. The MERV 13 filter should be used if allergies are a serious concern and there are tobacco smokers in the house.

 

What Does MERV Rating Mean?    What is a MERV Rating?

MERV stands for Minimum Efficiency Reporting Value.   This is  the primary rating system used for air filtration in the United Stated and around the world.

It is designed to measure a filter’s ability to capture and hold particles and pollutants. The higher the MERV rating, the more particles – dust mites, pet dander, air allergens, etc – your filter will capture.
Matching the right MERV rating to your needs will improve your home’s air quality and will extend the life of your furnace or air conditioner.

 

The MERV Ratings are as follows:

• MERV 6: Change every 30 Days
• MERV 8: Change every 60-90 Days
• MERV 11: Change every 60-90 Days
• MERV 13: Change every 60-90 Days

Check your unit because when the MERV ratings increase they capture more particles, but they do reduce the airflow.  Just check to see what your unit suggests!!

Where are they made?

At Sheridan Supply, our air filters are American-Made.   That is really important to us.   Country of Origin laws require that most products manufactured outside of America bear labeling that tells consumers where the product is made. This label should be visible on the product itself or the packaging in which it arrived.

Are the home air filters electro-statically charged?

Yes, many air filter brands use an electro-statically charged filter media. Fiberglass air filters are far less common today and were never designed to improve air quality, rather they protect HVAC systems from large dirt and debris.

Actual Size vs. Nominal Size     (The Size Of Your Air Filter)

We at Sheridan Supply believe that when you are looking to replace your air filter, there are essentially two different sizes you need to understand – Actual Size and Nominal Size.

The Actual Size consists of the true dimensions of your air filter when you are measuring the length, width and thickness.  This usually includes a fraction of an inch. For example: 19 1/2 x 19 1/2 x 3/4

Air Filters are NOT sold by their actual dimensions!  They are actually rounded up and that number is what is used to label filter packages. This measurement is referred to as the “Nominal Size”.  So get a pencil ready and measure and write down your numbers!

So a filter with:

• Actual Dimension of 19 1/2 x 19 1/2 x 3/4

• Will have a Nominal Size of 20 x 20 x 1

• Nominal Size is the measurement to look for when buying your replacement filters

Example:

Nominal Size

Actual Dimensions

Example A

20 x 20 x 1

19 1/2 x 19 1/2 x 3/4

Example B

16 x 25 x 1

15 1/2 x 24 1/2 x 3/4

That’s it! You now know the difference between “Actual Size and Nominal Size”.

How Do I Change My Air Filter?

At Sheridan Supply, we feel that regular maintenance of your home’s expensive cooling and heating system is essential to ensure it operates efficiently. Proper maintenance will keep good air quality in your home, increase the life span of your expensive system, and consume less energy which will lower your utility bills..

Where do you live ?  Are you in the Northeast or the Southwest ?   Is your unit running all year or only every 6 months ?  We suggest that your filters should be changed every 30 to 90 days depending on the type and efficiency of your filter. Energy Star (www.energystar.gov), filters should be changed every month during peak summer and winter months when your HVAC system is operating at highest capacity.

To change your air filter, we suggest these easy steps:

• Step 1: Buy a New Air Filter – Before buying a replacement filter, check your owner’s manual to identify the right number or size of your filter – it could also be printed on the side of your existing air filter.(see our article on How do I Measure My Air Filter)

• Step 2: Turn Off Your HVAC Unit – For safety, always turn off your HVAC unit before attempting to change the filter. If you can’t figure out how to turn off the unit, turn off the circut breaker.

• Step 3: Remove the Dirty Air Filter – Most air filters are located to the right or bottom of the unit and should easily pull out of the slot. Although not common, some filters are found in air vents instead. If that is the case, you might need to contact a HVAC professional for assistance.

• Step 4: Insert Your New Air Filter – There are arrows on the new filter to indicate which side should be facing the outside air. The filter should slide into place easily. You want the arrow to follow the direction of the air flow.  We suggest that you take a black marker and mark On the unit which way your air flow goes.  If you are confused, turn on the unit to determine this.   You might even want to mark your filter size ON the unit.