Here are some of the things that both the homeowner and contractor should do before an installation:

• A load calculation should be performed on the structure and the homeowner should be shown the calculation and it's results

• Equipment should be sized based upon the load calculation.  When choosing equipment bigger is not always better.  If the unit installed is too large and does not operate long enough to remove the humidity from the air.  The result can be very uncomfortable.

• Ducting should also be sized based upon the load calculation.  Each room will need a different amount of air flow to maintain comfort and the ducts and registers should reflect this.

• Return air (both grill and duct) must be sized correctly for the efficiency of the entire system.     Improper sizing can cause your compressor to cycle on and off and lead to premature damage and possible replacement.

• Supply registers placement and size should also be determined by the load calculation.  The size and placement of the registers is determined by the amount of air that needs to be delivered to each specific area of the building.

• If you have an attic system and the secondary condensate drain is not located above a window or door, a leak could do serious damage to your ceiling.  The primary condensate does not have to be visible, but if it should get plugged, the secondary drain comes into play. 

• Each home should have a main duct or trunk that extends from the plenum of the unit through most of the length of the house.  Some homes will require more than one trunk. 

• Most registers should be adjustable by the resident or homeowner.  Fixed flow registers are cheaper, but offer the homeowner no control over airflow.

• You should only use HVAC (Heating, Ventilation & Air Conditioning) contractors that have an established track record.  Stick to an established and reputable HVAC dealer that you know will be available to do your warranty work and any necessary repairs down the road.

• The entire system should be sealed properly to prevent any leaks that could cost the homeowner money.