Changing your furnace filter is a must for improved air quality and lower energy bills. The general rule is to switch it out every 90 days, though your lifestyle and the type of filter you choose may require you to change it more often. Keep an eye out for signs that it's time for a new filter. If your furniture gets dusty quickly or your furnace runs longer than usual, the filter may be clogged and no longer effective.

Fortunately, changing the filter is a simple process. Loosen the screws on the filter cover if it's located behind a return-air vent, or pull it out from the side of the furnace if it's in a slot. Have a trash bag ready as the filter will be dirty and can be discarded with your regular trash. Then, insert the replacement filter into the empty slot and mark your calendar for the next switch.

Making sure you have a clean furnace filter is essential for optimal air quality and energy efficiency. Follow the guidelines and watch for signs that the filter needs to be replaced, and you'll be able to enjoy the benefits of a clean filter in no time.

Air filters come in all sorts of shapes and sizes, and they are referred to in different ways - Nominal Size and Actual Size. So what's the difference?

Actual Size is the exact dimensions of the air filter. So, if you measure your filter, it may measure 15-1/2' x 24-1/2' x 7/8' (15.5' x 24.5' x .875'). This size is important to know, but it's not usually labeled this way. Most filters (but not all) are a bit smaller than the size they are listed as - this is where Nominal Size comes in.

Nominal Size is the size that the air filter is labeled as. In our example, the 15-1/2' x 24-1/2' x 7/8' (15.5' x 24.5' x .875') would be labeled as a 16x25x1. This is the size you would order.

There is one exception - air cleaner filters. Occasionally, they can be larger than the nominal size. For example, the Honeywell FC100A1003 is labeled as a 16x25x4 air filter, but the actual size is 16' x 19-7/8' x 4-3/8' (16' x 19.875' x 4.375') - thicker than the 4 inch nominal listing. So be careful when ordering replacement filters for name brand air cleaners!

Are 4-inch air filters worth it? The answer is a resounding yes! A 4-inch thick air filter offers numerous benefits over a 1-inch filter, including improved airflow, greater longevity, and maximum filtration potential. Plus, at FilterBuy, the price difference between the two is minimal. Therefore, if it fits your furnace, a 4-inch air filter is definitely worth the investment.

But what if the air filter compartment in your furnace is only 3” thick? In that case, a 1-inch furnace filter is the better choice, followed by the 3-inch filter. If the only difference is thickness, then the 2-inch filter is the one to go with.

It's important to always use the thickest air filter you can, as it will offer the most efficiency. However, never try to force a filter into a space that it's not designed for, as this can cause damage to the system and lead to decreased efficiency. 

When dropping down by an inch, such as using a 4-inch filter instead of a 5-inch, the difference shouldn't be too significant. On the flip side, using a 1-inch filter in a compartment that can accommodate a deeper filter may cause a loose fit, allowing unfiltered air into the ductwork.

Let's start with the basics: a three to four-inch filter should be replaced every six to nine months. But if you've got a thicker, five to six-inch filter, you'll get up to twelve months out of it. Keeping your filters clean and up-to-date is essential for peak performance from your heating and cooling system, as well as for clean air you can breathe easy.

To make sure your filter is in tip-top shape, check it every month. If it's time for a replacement, you'll notice an off-white color with visible dust and particles collected.

Not sure what size filter you need? The best thing to do is consult your manufacturer. Using a filter that's too thick for your system can impede air flow, so be sure to get the right size. If you want to upgrade your filter, you can have a filter cabinet installed. This allows for a higher efficiency filter, while still giving you easy access to check or replace it.

No matter your needs, our HVAC professionals can help. They'll give you a recommendation on the best filter for your system and household, and even install the cabinet if you need it.

When it comes to air filters, it can be hard to decide which size to go for. With so many options available, one of the most frequent questions we get asked is ‘what size air filter do I need?’

Air filter sizes are determined by the thickness, length, width and height of the filter. Generally, most air filters are 1 or 2 inches thick. However, you may find some that are between 3 to 6 inches in thickness. Thicker filters are more efficient, and they also last longer as they have a larger surface area to trap and remove air pollutants.

A 1-inch air filter needs to be replaced monthly, while a 4-inch filter can go six months without needing a substitute. However, replacement schedules differ depending on the brand and type of air filter.

In some homes, you may find 2-inch filters, and if you need a 3-inch filter, you have a one-of-a-kind HVAC system. 4, 5 and 6-inch air filters are typically found in whole house filters installed into an air handler, which is near your HVAC system.

Thicker air filters, such as 4 to 5 inches, are better in terms of providing a tight fit that prevents dirty air from passing through. They are less restrictive, so more filtered air can pass through and this offers better filtration.

So, to sum it up, 1 and 2-inch air filters are used in standard HVAC systems, while 3 to 6-inch filters are installed in larger HVAC systems. Ultimately, the filter size you choose depends on the type and size of your HVAC system.