19
* The above airflow data for reference only.
* In any stituation , the airflow of the unit should be in the range of 80% to 130% of 400CFM/Ton.
● The air distribution system has the greatest effect on airflow. The duct system is totally controlled by the contractor. For this
reason, the contractor should use only industry-recognized proce dures.
● Heat pump systems require a specified airflow. Each ton of cooling requires between 350 and 450 cubic feet of air per minute
(CFM), or 400 CFM nominally.
● Duct design and construction should be carefully done. System performance can be lowered dramatically due to poor duct
design.
● Air supply diffusers must be selected and located carefully. They must be sized and positoined to deliver treated air along the
perimerter of the space. If they are too small for their intended ai rflow, they become noisy. If they are not located properly, they
cause drafts. Reture air grilles must be properly sized to carry ai r back to the blower. If they are too small, they also cause noise.
● The installers should balance the air distribution system to ensure proper quiet airflow to all rooms in the home. This ensures a
comfortable living space.
● An air velocity meter or airflow hood can give a reading of system CFM.
● During installation, installer should select the air speed accor ding to the actual setting static pressure. Please refer to the
Table
7-1
AIRFLOW PERFORMANCE DATA.