Air Handler Fan Speed Too High

One in the condenser unit and another in the air handler.

Air handler fan speed too high.

Turn the power on and test the air handler s fan. Both fans have an equal part in cooling your home. It s been a long standing assumption that you should use the high speed tap for cooling and low speed tap for heating when using a constant speed fan. You should be able to hear a difference from the former speed.

If a blower speed is set too high your ac might not be operating optimally. The same type of assumption leads users to believe their variable speed dip switches are correctly preset from the factory. This is because the evaporator coil will not be able to adequately dehumidify the space in need of cooling. If you set the airflow too high the air coming out of your registers will be too cool and your system efficiency and your comfort will suffer.

There are 2 fans in your air conditioning system. Contrary to popular belief fan speed settings aren t always correct from the factory. We usually set the fan speed to keep the temperature rise of the air passing through the system between roughly 40f 65f depending on the age and efficiency of your system. Air speed switches have become the standard on modern hvac systems.

In general higher air handler unit ahu speeds when running in cooling mode will give quicker cool down of the occupied space and are suitable during daylight hours when the cooling load will be highest. On the other hand if the blower speed is too low your evaporator coil is at risk of freezing.