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FactHP - In Use Factors for Heat Pumps and other energy technologies in Residential Buildings

Duration: 24 months (December 2018 – December 2020)
LIT Project Budget: €61,900
Total Project Budget: €77,600


As Ireland transitions to a clean and secure energy future, it is vital that predictions of energy performance of buildings are as accurate as possible. FactHP will define 'In Use Factors' for heat pumps in particular scenarios, thereby informing the Sustainable Energy Authority of Ireland (SEAI) and policy makers on the actual energy performance, associated energy and CO2 savings of this technology.

The performance of heat pumps will be assessed in 40 domestic buildings with a range of dwelling types (detached/semi-detached etc), scenarios (new building and retrofit) and heat pump type (air & ground source). Predictions made by the SEAI's Dwelling Energy Assessment Procedure (DEAP) of the heat energy required for the dwellings and the electrical energy required to operate the heat pumps will be compared to actual metered heat and electrical readings for a 12 month period. 

Comparison of 'predicted' to 'actual' energy performance will help determine if an 'in-use' factor is relevant or if refinements to the prediction methods are required.

Objectives and Aims of the Project

There has been limited analysis of Irish HP performance in Irish dwellings to date. FactHP has the following objectives:

  • To increase the availability of independently monitored domestic heat pump performance data. FactHP will provide this data for 40 systems.
  • To use this monitored data to calculate combined space heating and hot water Seasonal Performance Factor (SPF).
  • To calculate the combined space heating and hot SPF as predicted by DEAP.
  • To compare the two figures for each system and to provide analysis on the agreement or otherwise of the SPF values. 
Latest FactHP news
21 April, 2020:
Over 4 million tonnes of C02 emissions could be saved per year – Superhomes 2.0 report

Further Information

Project factsheet

Project website


Seamus Hoyne
Project Co-Ordinator

Padraic O' Reilly
Senior Project Officer

LIT Activities (Development Unit)

  • Identify suitable candidate buildings for analysis, starting with systems already fitted with suitable monitoring equipment
  • Develop independent monitoring systems in line with the project’s QA requirements
  • Install this monitoring equipment in houses without pre-existing monitoring equipment
  • Complete analysis of HP performance over 1 heating season in 40 homes
  • Based on comprehensive analysis of SPF, define relevant In Use Factors for different HP technologies
  • Inform and influence future policy and compliance tool development for HP technologies