Improving Gas Furnace Performance: A Field and Laboratory Study at End of Life

2014 Building America House Simulation Protocols

“…Default efficiencies for equipment not listed in the table may either be interpolated or estimated by referring to the original references. Preliminary data on gas furnaces (Brand et al 2013) show no relationship between equipment age and efficiency degradation. Air conditioners and heat pumps are known to degrade because of poor installation quality, lack of maintenance, and/or age; however, there is not enough data to establish a relationship between equipment age and performance degradation.…”

2014 Building America House Simulation Protocols

“…AFUE values for gas furnaces from 2012 ASHRAE HVAC Systems and Equipment (I-P Edition), Chapter 33, Table 1. b Gas refers to either natural gas or propane c Source: 1987 National Appliance Energy Conservation Act Preliminary data on gas furnaces (Brand et al 2013) show no relationship between equipment age and efficiency degradation. Air conditioners and heat pumps are known to degrade because of poor installation quality, lack of maintenance, and/or age; however, there is not enough data to establish a relationship between equipment age and performance degradation.…”