Heat Pump Plus

Project Information

Heat pumps can offer a viable alternative for many homes to transition from fossil fuel-based heating systems to a much cleaner system.


The Heat Pump Plus project investigated methods and mechanisms to gather high quality data on the factors which dictate how effectively heat pumps operate, and the impact energy efficiency measures can have. The project funded by Energy for Tomorrow started in December 2021 and officially finished in December 2023.


The project engaged with over 70 Orcadian properties during the recruitment period, after which over 40 house visits were conducted for the eligible participants. Different level of monitoring was offered to the participants, but about 23 properties had their heat pump consumption successfully isolated, 7 of which also had heat meters fitted for Coefficient Of Performance (COP) calculation. The remainder of the monitored properties had the whole house consumption monitored.

The data collected during house visits, through the survey and the monitoring devices into place helped inform the study. Our team collected different types of information:

  • Specifics of the property and system in place
  • Heating habits
  • Perception of the system
  • Electricity consumption of the system

Where possible the project team used this information to assess the heat pump’s function, and proposed measures to increase the performance of the participants’ heating systems that could contribute to energy savings.


The analysis of load profiles of the heat pumps highlighted the fact that many of the monitored systems seem to have some type of cycling issue. 

‘Short Cycling’ was a dominant issue, with 14 of the monitored heat pumps showing significant short cycling; with more than 50% of the cycles being shorter than 15-minutes).

There are several potential reasons why these systems are prone to short cycling.  A key factor suggested by the data analysis points to systems running on partial loads for some systems while it pointed to oversized systems for others. Improper system settings could also have been linked to cycling issues.

Another likely reason is the oversizing of some of the heat pump systems.  Indeed, seven of the monitored heat pumps showing signs of oversizing, while three were likely to be undersized according to the load profiles.

The data also suggested that some monitored properties were insufficiently insulated, resulting in high heat loss and the heat pump having to cycle more often to obtain the desired comfort level. Focussing on insulation before installation of a heat pump system is key to limiting heat losses and mitigates the need to use bigger, more energy-intensive heat pumps.

Documentation Available

The observations made suggest that proper guidance should be provided to householders to ensure they know how to effectively operate their systems and avoid problems.  These operational best practices and the project’s main report can be found at the links below

Next Steps

Following the completion of the HPP project, CES will be looking to disseminate the results, while also replicating the activities in community spaces with the Innovate UK funded ‘Rural Energy Hub’ project.


Read or download the project report and best practices report below.

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