ASHRAE standard to focus on ducts
A proposed new standard will evaluate these problems and estimate energy savings, as well as aid in equipment sizing, according to Mark Modera, chairman of the committee writing ASHRAE Standard 152P, “Method of Test for Determining the Designated Seasonal Efficiencies of Residential Thermal Distribution Systems.”
The proposed standard closed for its second public review period September 24. It is designed to make it easier to calculate annual energy needs and hvac equipment capacities. It applies to single-family detached and attached residences with thermal distribution systems (duct systems, hydronic systems and electrical-wire distribution systems.)
The standard will allow energy comparisons between different systems, Modera said. “It allows users to demonstrate the benefits of better duct sealing, improved insulation, good air flow and relocating ducts without having to develop calculation methods.”
In addition to ductwork, the standard looks at several other parameters: building climate, duct location, duct surface area, duct insulation, hvac equipment capacity, air-handler flow, and supply and return duct leak flows into and out of unconditioned spaces.
The need for this standard, according to Modera, stems from research indicating a 10-30% energy savings associated with sealing duct leakage.