Question: How often do you need to change your air conditioning filter?
Changing your air conditioner filter or furnace filter is the most important maintenance task there is if you want to keep your equipment operating at maximum efficiency. Allowing an air conditioner filter to become so dirty that it begins to restrict air flow can cause evaporator coils to ice up, operating efficiency will decrease and even prevent the unit from maintaining the desired space temperature.
The easy answer to this question is every three months and you should not have any problems. But there are really many variables to consider when trying to provide an accurate answer to this question. Often sales people can quote efficiency ratings or MERV ratings and provide you with their standard recommendation but they often don’t really understand how air conditioners operate.
Here are a couple of articles I wrote about this topic. The first one I wrote today. The second one I wrote some time ago but found it only after I wrote the one today. Anyway, they are similar but each provide some different information. Please leave comments or email questions if you have any.