If you want a furnace filter, then there are some guidelines that should help you with this decision. There are two main sizes that these filters come in, namely: standard size and compact size. The best way to figure out what size filter for your furnace to use is to first remove the existing filter from your furnace and look at it’s measurements. These are usually printed on one of its sides.
One thing you will want to keep in mind is that the actual sized size of your furnace filter will vary by as much as half an inch for every dimension. That’s why it’s important to measure both the front and back surfaces of the furnace filter to get an accurate comparison. When you are comparing sizes, make sure you take note of all the dimensions in the furnace filter. Take note of how much the front and back surface of the filter are bigger than the front and back surface of the filter found inside your furnace. This is how large the filter needs to be in order to completely cover your furnace. Then, you can figure out how big the new size filter needs to be to cover your furnace.
Now that you know what furnace filter sizes there are and how they are measured, the next thing you need to do is figure out which size of filter fits in your furnace. It’s not as hard as it seems. All you have to do is measure the dimensions of your furnace filter on each side of the furnace. For a standard furnace, this would be about three inches long and three inches wide. If you are measuring the filter used on your high efficiency furnace, you would need to measure the filter on the back of your furnace (the outside of the furnace) as well as the front of the furnace (on the front of the furnace). Remember to measure both the front and back of the furnace. Once you have found the size of the furnace filter for it, stick it on the furnace.