If that is the case for you, you can possibly stretch it to a few months, but even if your A/C filter does not look dirty after many months you should still change it.
Whether you are looking to save currency or are interested in helping to preserve the planet and have a smaller carbon footprint, it only makes sense to look for ways to save energy, including tips about saving on your A/C bill. What are some of the things you can do to lower your cooling or heating bill? If it is A/C, one thing you can do is start outside. That is, plant some trees or bushes that will supply shade. Having shade keeps your A/C from having to start with a temperature control that is way too high. Another thing to do is to have curtains or blinds in your windows. Personally, I like to use insulated curtains, otherwise known as blackout drapes, because they do help to keep out the sun and the light, plus I think that my A/C does not have to work so much when I have the blackout curtains closed. Another thing to do is to make sure that you change the A/C air filter on a regular timeframe. I have a dog and I prefer to change my A/C filters every month, but other people do not find that their A/C filter is at all dirty after a month. If that is the case for you, you can possibly stretch it to a few months, but even if your A/C filter does not look dirty after many months you should still change it. Another thing to do to save on your A/C and have your home’s climate control system be more efficient is to use ceiling fans to your advantage. I have never had a house without ceiling fans down here in the southeast, and I never will. Sitting under a ceiling fan makes you feel cooler even though the temperature is not any lower than it is without the fan. This means you can have your temperature control set a few degrees higher plus still be just as comfortable.