Evaluation and Demonstration of Actual Energy Efficiency of Heat Pump Systems in Buildings

Ongoing (2022 - 2027)


Certain heat pump systems in buildings have previously been found to exhibit low energy efficiency under low partial load conditions, while other heat pump systems have been able to maintain higher energy efficiency under the similar conditions. Therefore, technical guidance on how to improve the overall energy efficiency of such heat pump systems is critical information for many engineers and HVAC system designers. Further, public policy and decision makers require support on how requirements to follow such technical guidance can be implemented within building energy codes and regulations.

The overall objective of this project is to establish the scientific basis for more accurate estimation of the energy efficiency of heat pump systems for heating and cooling of buildings and for more reliable and transparent design strategies for building applications of heat pump systems. To meet this objective, the following activities are being carried out:

  • Literature survey and collect existing field monitoring results on the behaviour of heat pump systems in buildings. The data shall include at least input (energy use) and output (thermal load) of heat pump systems, peripheral conditions such as outdoor temperature, characteristics of the heat generators such as product test results and specification of compressor(s), and characteristics of buildings and overall HVAC systems.
  • Development of a manual on monitoring methods for energy efficiency and other characteristics of heat pump systems in buildings, and new data acquisition techniques on which to develop a database.
  • Development and validation of alternative methods for predicting energy efficiency and energy use of heat pump systems in buildings under different conditions including partial load ratios, by utilizing product information based on existing test standards and protocols.
  • Development of design guidelines for more energy efficient heat pump systems with demonstration data from applications in buildings.

The project is producing a series of official deliverables aimed at the research community, and these are listed below:

  • State-of-the-art report on existing monitoring results of heat pump systems and other heat generator systems including specifications of monitoring methods,
  • State-of-the-art report on methods and product parameters for estimating energy use by heat pump systems,
  • Recommendations of protocols to monitor actual characteristics and behaviour of heat pump systems, and
  • Database of monitoring results on heat pump systems and on other heat generators in buildings. 

It is also creating two further official deliverables aimed at specific target audiences as follows: 

  • Design guidelines of heat pump systems in buildings based on the evaluation of energy use and efficiency, which will be aimed at the HVAC system designers and engineers, and
  • Recommendations for policy and decision makers, which will be aimed at public policy and decision makers and their technical advisers.

Operating Agent

Dr Takao Sawachi
Building Research Institute
1 Tachihara
305-0802 Tsukuba, Ibaraki
Tel: +81 29 864 2151


[Provisional] Australia, Brazil, Canada, China, Japan, The Netherlands, Switzerland