Why Is My Central Air Not Blowing Hard Enough?

Registers Closed

• Central air conditioning is a forced-air system. The air is chilled at the evaporator, and a fan forces air through the ducts. The ducts empty into the various rooms in your home through a series of registers, or vents. These vents can often be closed off by the homeowner to prevent cooling in parts of the house that may not need it. But if you have unintentionally closed or partly closed registers throughout the house, it will affect the overall airflow from the ducts. Check them to see whether registers are open all the way. If they are not, adjust them so they are. This will increase the air speed out of the system.

Fan Problem

• You may have a problem with your fans if you aren’t feeling a good gust of cold air from your registers. If they are open, the fan should be powerful enough to push air through the ducts and blast it out into the house. If the fan motors are bad on the blower, the fan will not spin and the air will not be forced out at all. A dirty fan blade on the blower fan can also affect how fast it spins and may slow the airflow considerably. Your fans may also be set to low speed. Setting the blower fans to high speed can help increase how hard the air conditioning blows.

Ductwork

• The airflow from your blower to your home’s registers takes place in a series of ducts under the house, in the walls or ceilings. The ducts must be clear of debris or leaks to maximize the velocity of the air reaching various rooms. If your ducts are clogged with debris or if they have rusted or become unattached from one another, much of the air pressure will be lost to the outside of the ducts. Have the ductwork inspected for cleanliness and integrity.

Filters

• Think about the last time you changed your air filter on the air conditioner. If you can’t recall when that was, you are likely overdue. When the air filter becomes full of dust, lint and other debris, it can choke off the airflow through the system. This can cause overheating and may reduce how hard your system is able to blow.