Because forced-air heating and cooling systems are assembled on site from a great many parts, there are many ways for installers to make mistakes. Researchers have repeatedly shown that a high percentage of residential forced-air systems have major problems, including duct systems that are poorly designed, poorly located, and leaky. Other problems include incorrect refrigerant charge and too much or too little airflow over the cooling coil.
The classic solution to these problems — in addition to the obvious step of better duct system design — is to insist on a more rigorous commissioning process. “Commissioning” refers to the process of testing and adjusting installed equipment to be sure that it performs in accordance with the manufacturer’s specs and the designer’s intent. Although commissioning is rare for residential HVAC systems, it is a routine step for commercial and institutional buildings.
Energy Star makes commissioning mandatory
As I noted in an earlier blog, The Energy Star Homes Program Raises the Bar with Version 3, the Energy Star program has decided to include requirements for the commissioning of forced-air HVAC systems, beginning January 1, 2012. The following commissioning steps will be mandated: