Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Effect of Heat Pump Commissioning Faults on Annual Energy Use



Piotr A. Domanski, Hugh Henderson, William V. Payne


The study sought to develop an understanding of the impact of commissioning common faults the energy consumption of an air-to-air heat pump installed in a single-family house. Through annual simulations of the house/heat pump system, the study found that duct leakage, refrigerant undercharge, oversized heat pump with nominal ductwork, low indoor airflow due to undersized ductwork, and refrigerant overcharge have the most potential for causing significant performance degradation and increased annual energy consumption. Depending on the faults involved, the effects of simultaneous faults were found to be additive, little changed relative to the single-fault condition, or well-beyond additive. A significant increase in annual energy use can be caused by lowering the thermostat setting in the cooling mode to improve indoor comfort in cases of excessive indoor humidity levels due to installation faults.


air conditioner, commissioning, fault detection, heat pump


Domanski, P. , Henderson, H. and Payne, W. (2010), Effect of Heat Pump Commissioning Faults on Annual Energy Use, [online], (Accessed April 22, 2024)
Created January 24, 2010, Updated May 12, 2017