Measuring your air filter is actually a pretty straightforward process, but it’s crucial to get it right to ensure you’re buying the correct replacement. Here’s a step – by – step guide.
First, you need to know that air filters are typically measured in three dimensions: length, width, and depth. The depth is sometimes referred to as the thickness.
Length and Width
- Use a measuring tape. For most standard air filters in HVAC systems, you’ll measure the two outer sides of the filter. Make sure to measure from one end to the other in a straight line. For example, if you’re looking at a rectangular filter, measure the longer side for the length and the shorter side for the width. Measure in inches. Be as precise as possible, rounding up to the nearest whole inch if you’re a fraction off. In some cases, filters might be measured in centimeters, but in the US, inches are more common for HVAC filters.
- When measuring, double – check your measurements. It’s easy to make a mistake, especially if the filter is a bit dirty or in an awkward location. Measure at least twice to confirm the accuracy.
Depth (Thickness)
- This one can be a bit trickier. The depth is the measurement from the front to the back of the filter. For a flat – panel filter, you can use the measuring tape to simply measure the thickness of the filter material itself. However, for pocket – style filters, you need to measure the depth of the pockets. Start from the outer edge of the filter frame where it attaches to the HVAC unit and measure all the way to the deepest part of the pocket.
- If your filter has a frame around it, make sure to include the thickness of the frame in your depth measurement.
Now, a couple of important tips. Some filters might have a model number or size printed on them. If you can find this, it can save you a lot of time. But don’t rely solely on this as sometimes the print can be faded or inaccurate. Also, when you’re looking to buy a replacement filter, take your measurements with you. Some hardware stores might have a chart to help you match your measurements to the right filter, but having the exact numbers on hand ensures you get the perfect fit.
If you’re still unsure about the measurements or if you have a particularly odd – shaped filter, it might be a good idea to consult an HVAC professional. They’ll be able to accurately measure your filter and recommend the best replacement option.