Filters Fast Logo Header
RETURNING CUSTOMER?
SIGN IN. CONFIRM ORDER. DONE.
Free Shipping on orders over $99 | FREE 365-DAY RETURNS

25x29x4 Air Filters


Depth
Most common house filters are 1" in the depth or thickness. If you measure your filter to find the real thickness you will find that it isn't the same dimension as it states on the filter. This difference in the real dimension to the printed dimension are industry standards and can be confusing. The printed size on a filter is called nominal size and is not the real dimension of the filter. So a 1" thick filter is normally .75" thick. To make it easier to talk about sizes we use the nominal dimensions to refer to filter instead of the actual or real size. Because you are creating a filter by selecting the real dimensions, it is important to know the real dimensions of your filter instead of the nominal or printed dimensions that show on your filter. We will show you the nominal dimension for the Depth or thickness because there are only 1",2", or 4" sizes. Now you would select 1" for your filter if you are replacing a .75" filter, if your filter is 1.75" that would be a 2" filter and a 4" is 3.5"
/
Size
Nominal Size: The printed value of a filter dimension. (15"x20"x1")
Actual size: Actual or real sizes of filters are typically .5" less than the printed dimension or nominal value listed on the filter. A filter of 20"x24" would be 19.5"x23.5"
Need help? Call 866-438-3458. Our sales line is open 7 days a week between the hours of 9:00 am and 9:00 pm EST.
Good
MERV 8 Filters Fast® 4" AC and Furnace Air Filters 3-pack
MERV 8 Filters Fast® 4" AC and Furnace Air Filters 3-pack
$20.32 per filter
Size: 25x29x4 @ $60.95/case
8
MERV 8
Equipment Protection
Fine Dust
Lint and Dust
Auto Emissions
Pollen
Smoke
Pet Dander
Very Fine Dust
Mold Spores
Bacteria
Dust Mites
Add To Cart
In Stock
Ships in 1 to 2 business days
Replace every 180 days
Better
MERV 11 Filters Fast® 4" AC and Furnace Air Filters 3-pack
MERV 11 Filters Fast® 4" AC and Furnace Air Filters 3-pack
$23.65 per filter
Size: 25x29x4 @ $70.95/case
11
MERV 11
Equipment Protection
Fine Dust
Lint and Dust
Auto Emissions
Pollen
Smoke
Pet Dander
Very Fine Dust
Mold Spores
Bacteria
Dust Mites
Add To Cart
In Stock
Ships in 1 to 2 business days
Replace every 180 days
Best
MERV 13 Filters Fast® 4" Allergy AC and Furnace Filter 3-Pack
MERV 13 Filters Fast® 4" Allergy AC and Furnace Filter 3-Pack
$28.65 per filter
Size: 25x29x4 @ $85.95/case
13
MERV 13
Equipment Protection
Fine Dust
Lint and Dust
Auto Emissions
Pollen
Smoke
Pet Dander
Very Fine Dust
Mold Spores
Bacteria
Dust Mites
Add To Cart
In Stock
Ships in 1 to 2 business days
Replace every 180 days

Air Filter FAQ

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

Yes, both AC filters and furnace filters are the same thing. 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?

Always 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.

What is air filter MERV rating?

The Minimum Efficiency Reporting Value (MERV) is used by manufacturers to explain how efficent 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 airborn 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 micorn 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?

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 quailty check the filter monthly. If you notice the filter material is greatly discolored or noticably dirty change out the filter. Failing to replace air filters as recommened can lead to reduced system efficieny, greater energy costs, and poor air quailty.

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. For many allergy sufferers 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 can impact air flow and reduce equipment life.

Which air filter is best for my home?

Your choice in air filter should depend on needs. MERV 8 filters are perfect if you have no pets and allergies are not a serious concern. MERV 11 filters are recommend for occasional allergy sufferers and homes with pets. A MERV 13 filter should be used if allergies are a serious concern and there are tobacco smokers in the house.

Where are they made?

Filtersfast brand air filters are proudly made in America. While the manufacturing location of products can vary from company-to-company, 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 visable on the product itself or the packaging in which it arrived.

Are the home air filters electrostatically charged?

Yes, Filtersfast, Filtrete, Carrier, among many other air filter brands use an electrostatically 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.