Verifying energy savings with minimal metered data: The Hunter heat pump analysis

摘要

In November 1992, Hunter Army Air Field (AAF) completed the installation of 489 air-source heat pumps -- a new heat pump and air-handling unit for each residence. The air-source heat pumps replaced older, less efficient, air-conditioning systems, fuel oil-fired furnaces, and fan coil units. Hunter AAF originally contacted to upgrade the old family housing heating, ventilating, and air-conditioning (HVAC) systems with high efficiency air-conditioning systems and natural gas furnaces, but an alternative proposal and following energy studies indicated that heat pumps were a more life-cycle cost-effective alternative. Six months after the heat pumps were installed, Hunter's energy bills appeared to be increasing, not decreasing as expected. In early 1994, Pacific Northwest Laboratory' (PNL) began an analysis to determine if there were any energy savings resulting from the heat pump installation as predicted by previous energy studies. The problem is that the HVAC systems are not specifically submetered to support verifying the resulting energy savings and, as is the case with most federal facilities, even the homes are not individually metered. Savings verification needed to be accomplished with die existing and available metered data. This data consisted primarily of monthly electric submeter readings from the two housing subdivision meters, historical fuel oil delivery records for family housing, and monthly base-wide electric bills. The objective of the study is to verify the change in energy consumption in family housing and, to the extent possible, identify how much of the change in consumption is attributable to the new HVAC system and how much is probably attributable to other factors, such as the weather.