ARLINGTON, Va. — The Air Conditioning Contractors of America (ACCA) has published its latest technical bulletin entitled “Understanding CAZ Depressurization Testing.” Technical bulletins are provided to ACCA members at no cost and cover a variety of topics related to system design, installation, and maintenance.

This new bulletin is intended to serve as an aid to contractors in evaluating failed combustion appliance zone (CAZ) depressurization testing procedures reported to homeowners by weatherization and home performance practitioners. ACCA said understanding how the data was obtained provides a head start when evaluating homes that failed building performance tests. The procedures are explained in detail, so that HVAC contractors can double check the reported results. This additional background knowledge will help HVAC technicians explain the recommended repairs and how the corrective actions will resolve the reported problem.

In addition, there is an appendix containing ACCA’s guidance for testing combustion appliances based on industry-recognized depressurization testing procedures. These depressurization procedures were developed by the gas manufacturing industry. Additional parallel guidance for oil furnace and oil boiler applications has been provided in the appendix.

ACCA technical bulletins may be downloaded by members at www.acca.org/bulletins. For more information, visit www.acca.org.

Publication date: 9/24/2012