A $5 air conditioning filter will save you big money every month
As Property Managers we get calls 
weekly during the summer from residents complaining that their air conditioning has stopped, their electric bill is high or their air conditioning system is not keeping the their home cool.
weekly during the summer from residents complaining that their air conditioning has stopped, their electric bill is high or their air conditioning system is not keeping the their home cool.We send out a HVAC professional and discover the cause of the problem is not a high tech part failure…it is simply a very dirty filter that is preventing air from circulating over the cooling coils. A dirty filter causes the a/c system to work very inefficiently. This can result in much higher electric bills to cool your home because the system has to operate longer to cool the home. A dirty filter can also cause damage to the system. And because your lease requires the tenant to replace the filter when dirty if the HVAC technician indicates the cause of a repair is a dirty filter, the tenant gets the bill for the service call.
Some filters can become very dirty within a month of replacement, others may only need replacing very 2 or 3 months. So we recommend a quick monthly inspection just to be sure. Some homes have washable filters or more high-tech electrostatic filters that will have different operating procedures.
Also realize that no filter in the a/c return air grill can cause even more damage and high electric bills because the cooling coils become clogged with dirt and dust.
So save yourself lots of money on your monthly electric bill and avoid arguing with your property management company over a $300 HVAC repair bill and change out the $5 air conditioning filter.