Air Conditioning: What’s it about?

It’s all about “AIR!”

First, your home’s air conditioning system must be sized correctly to provide the proper CFM of air and BTUs of cooling to each room of your home.

What is CFM?
CFM (Cubic Feet per Minute) is a measure of volume of airflow rate. Visualize a basketball. A basketball is approximately 1 cubic foot in volume.

How many CFM’s does your system require?
For example, a typical 3 ton system (36,000 BTUs) requires a minimum of 1,050 CFM to a maximum of 1,200 CFM to perform to manufacturer’s specifications.

What are BTUs?
(British thermal unit) – 1 BTU is equal to the heat produced by burning a single wooden match or can be defined as the amount of heat required to raise the temperature of 1 pound of water by 1°F.

Once you have the proper airflow, you can cool it, heat it, dehumidify it and clean it, to provide you and your family with total personal comfort.

Bedroom airflow issues
How to know if it is a lack of supply air or lack of return air:

FIRST: Does the room cool fine during the day with the entrance door open?

SECOND: Is your problem only when the door is closed for privacy issues?

THIRD: If the room cools satisfactorily and only has issues when the door is closed, add a properly sized return air grill with duct work ran back to the air handler plenum.

FOURTH: If cooling is not adequate with door open, increase airflow supply, enlarge supply duct or add additional supply register with accompanying duct work coming from supply air plenum, plus add a return grill with accompanying duct work ran back to return plenum for good performance.

NOTE: The new building code requires all major rooms to have properly sized return air grills to allow free flow of return air back to air handler.


No filter… bad idea. You just turned your evaporator coil into an amazing “filter.” The evaporator coil is wet and without a filter installed, all the dust and dirt (even in the cleanest of homes) is being circulated and collecting on the coil–which in turn will cause the coil to be restricted and result in system malfunction.

Second requirement is for the health and well-being of occupants. A higher efficiency filter will provide cleaner air but will your system support the higher air flow restriction put on your system?

Your existing indoor unit (air handler) in most situations is already struggling and under-performing due to an undersized duct system. So, with good intentions, you install a pleated filter that is now making a bad situation worse.

What’s it all about?

Most pleated filters are a disaster. They require close to 50% of your air handler’s ability to move the proper quantity of air (CFM). Therefore, destroying your energy costs and premature failure of your air conditioning system.

In order for the homeowner to know what filter their air conditioning system can support, have your air conditioning technician test your system to find the total static pressure that your system creates without a filter. The difference between the manufacturer’s listed maximum static and the total static test that was just performed will tell you what filter to install.

Tip: Install a low efficient low static filter and spray it with cooking spray, such as “Pam.”