Do you know when to change your air conditioner filter? It's important to check and replace your air filter every month during peak season, according to ENERGY STAR. But how do you know if you need to clean or replace the filter? It's easy - just remove it from your camera and hold it up to the light. If light can easily pass through the filter and it's semi-transparent, leave it there. If light is difficult to pass through and it is visibly dirty, it's time to change the filter. The air cleaner is usually close to your home thermostat, in a return duct or right next to the air handler for your air conditioning system.
If you want to learn how to change the AC filter yourself, ask your HVAC service technician. They can show you where the filter is located, how to remove the old filter and insert the new one, and how to get the right filters for your system. The other potentially difficult part is making sure you use the right filters. The filter size is usually printed on the side of the filter. When in doubt, the simplest solution is to ask your HVAC technician to supply you with the correct filters, or to show you filter size information so you can order them yourself. In addition, there are more examples of where and how to look for filters in an air conditioning or hot air heating system.
These systems move air from a return chamber (connected to the end of the return duct of the system) through a cooling coil (for air conditioning) or a heat exchanger (for heating systems). The air cleaner may be in one or more common air returns or in the air handler, or less commonly, in a slot in the return air duct near the air handler. Normally, filters are placed inside this box in a location that will filter the air before it reaches the fan itself. It is usually located in the return air duct or in the fan compartment before the return air reaches the air handler. A small reduction in airflow and a little more in the cost of home heating can be the result of leaving things at the top of the return air intake. The large box filter shown (the company called it a Merv 1 filter) is located above the return air chamber that sits on a concrete floor.
We have seen a 100% improvement in air conditioning or heating flow when cleaning a heavily soiled fan. The photograph shows a vertical or upflow heating and air conditioning unit whose cooling section was mounted as an accessory above a hot air oven. If both heating and air conditioning systems share the same ducts, it is also possible that the air cleaner for both systems is located in or near the blower system of the furnace. Someone probably added this air intake (yellow arrows) to improve the total air flow through the system, but drawing the return air from near the oil or gas burner in a furnace can.