When the company installed our new heat pump and AC unit, they didn’t tell us what size air filters to use in the machine.
The first time I received a message from the thermostat to change the air filter, I was ready to go quickly. I grabbed a screwdriver and removed the outer lid. I looked everywhere on the air filter, but I couldn’t find the size at all. I thought it was strange that the air filter didn’t have any writing, but I guess the HVAC insulation company must get them directly from the factory. I tried not to worry, and I grabbed a tape measure, pencil, and small pad of paper. I measure the air filter from one side to the other and back again. The measurements that I got were 21 in long by 20 in wide. I didn’t want to wait to order the part online, especially when the local hardware claimed to have 37 air filters. I jumped in the truck and drove directly to the store. I stopped to grab some lunch, but I made my way to the store in record time. I searched through the aisles, until I located the place where all of the home air filter supplies are kept. They had about 50 or 60 different types of air filters, and I had to search for several minutes, before locating my specific size. Luckily, the air filter was reasonably priced, and I was back home in no time. I placed the new air filter into the machine, and it almost disappeared. Somehow, I purchased the wrong size or measured in correctly, because the air filter was way too small.