The four-inch-thick air filter has an advantage over the one-inch in terms of longevity, airflow and maximum filtering potential. If it fits your furnace, then a four-inch air filter will provide better air quality. The cost difference is often minimal.
Because it is four times as thick as a 1-inch filter, it has a much greater surface area for catching household pollutants. These larger filters also typically come with higher MERV ratings and can capture more contaminants (e.g., pet dander, smoke, allergens, and bacteria) than a 1-inch filter.
Higher MERV ratings work best when the filter is 4” thick or thicker because they trap extremely small particles, which means contaminants will build up quickly on the screen. If your system only fits a 1-inch or 2-inch filter, a high MERV rating could be detrimental.
At four inches thick, the 20x25x4 air filter offers more surface area to capture additional particles, lasts longer and delivers a host of other advantages. With a 20x25x4 air filter, homeowners: Have better heating and air conditioning. Breathe cleaner and healthier indoor air.
A three to four-inch filter can last for six to nine months. If you have a thick five to six-inch filter, it can last from nine to twelve months. By making sure that your filters are changed when they need to be, you can enjoy having a heating and cooling system that will work its best.
In general, this is how often changing furnace filters needs to be done: For 1- to 2-inch filters, replace them every 1 to 3 months. For 3- to 4-inch filters, replace them every 6 to 9 months. For 5- to 6-inch filters, replace them every 9 to 12 months.
MERV 11 is generally not too high for most home HVAC systems and provides effective filtration, capturing smaller particles like pet dander, pollen, and mold spores. This level is beneficial for households with allergy sufferers or pets, as it improves indoor air quality.
What Is the Most Common Size of Air Filter for a House? The most common size air filter for a house is usually 20 x 20 x 1, but this can vary depending on the specific HVAC system installed.
This extra depth gives the filter more room for airflow. That means that as the filter collects dirt and other debris from your air, it won't restrict the airflow in your furnace as much. This prevents damage to the furnace and gives the filter itself a longer lifespan.
UNDERSTANDING FILTER SIZES
Therefore, for example, a 16x25x4 filter is 16 inches long, 25 inches wide, and 4 inches thick. It's important to note that filters with different dimensions are not interchangeable due to variations in frame size and media area.
A thicker filter (4-5 inches) has more surface area and therefore allows more room for air to pass through. Thick filters, due to their increased surface area, also have other benefits like: Higher dust-holding ability (meaning it can catch a lot without blocking airflow)
Your air filters can also improve airflow throughout your home or office. When airflow is reduced, your HVAC system has to work harder to circulate air, which inevitably leads to higher utility bills. By reducing the amount of moisture in the air, air filters also help to prevent the growth of mold and mildew.
Selecting an incorrect size might appear insignificant, but it seriously hampers your system's performance and lifespan. Such a minor mistake leads to compromised efficiency and airflow restriction, which result in higher energy use, more maintenance work, and the need for frequent replacements.
A thicker air filter with a high MERV rating might trap more particles, but it could also restrict airflow if your system isn't designed to handle it. Always consult your HVAC manual before switching to a thicker filter.
As a result, it is important to change your 16x25x4 furnace filters at least every 3 months. You should also be aware of what types of 16x25x4 furnace filters are available and how often you need to change them based on their efficiency level.
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.
4” furnace filters should be replaced every 6-9 months. 5” furnace filters should be replaced every 9-12 months.
You may not need a MERV 11 filter or higher unless you have specific air quality issues or allergies. For the average household, a MERV 8 air filter can be good enough. You'll want to think about factors like how often you want to change your filters and what type of material do you want filtered out of your air.
Switch To Pleated Filters
Fiberglass air filters will get the job done, but in most cases, pleated air filters are much better. Pleated air filters capture smaller particles and are less likely to clog within a short period of time.
However, it's worth noting that filters with higher MERV ratings can restrict airflow. While filters rated 13 or below generally don't strain most HVAC systems, those rated above 10 might require professional installation.
The easiest way to find out what size filter to get for your furnace is to simply remove your current filter and look at its dimensions. These are typically printed along with one of the sides of your filter.
As you can see the 2 inch filter will serve our needs MUCH better than the 1 inch filter. Even if the duct system is in good shape, using this filter will keep the system from struggling.
For households working with tight budgets, MERV 8 filters offer cost-effectiveness and minimal upkeep requirements. Superior particle capture and enhanced air quality come with MERV 11 filters, making them suitable for dwellings with pets, allergies, or high pollution.
Furnace filters with a MERV 8 rating or higher can effectively remove pet dander from the air. On average, MERV 8 filters remove 85% of large air particles and 50% of small particles. The higher you go the better the filtration will be, but we don't recommend going higher than MERV 13.
MERV 11 is made of a thicker filter material than MERV 8. This means that more energy will be consumed to allow enough air to pass through. This increase in energy will cause a slow but inevitable deterioration of the HVAC components which is why you must maintain your furnace as often as you can.