Energy and environmental impacts of heat pumps for cooling and heating in the UK residential sector

By Eleni Oikonomou

Supervisors:

Tadeusz Oreszczyn

Michael Davies

2011 – 2016

The aim of this study is to assess the impact that a large scale take-up of residential air-source heat pumps (HPs) may have on summertime overheating, carbon emissions, energy use and peak power under current and projected future warm weather conditions in the UK.

Currently, domestic HPs in the UK are used primarily for heating, however many types can cool as well. Considering the expected increase in summertime thermal discomfort in the near future, the additional option of cooling may prove beneficial for their uptake. This is likely to cause a major increase in the country’s carbon emission, unless combined with a decarbonised electricity supply and only if the peak demand for electricity is not in the summer.

This study investigates the modelled year-round performance of air-source HPs under different fabric interventions and user behaviours in the nine most common dwelling typologies in England, as derived from the English Housing Survey 2010-11 statistical data. The initial calculations will be based on the algorithms of a non-dynamic tool (Standard Assessment Procedure 2009), which will be followed by a set of dynamic simulations (EnergyPlus). A sensitivity analysis will determine the most important parameters to be taken into consideration in the formulation of the stock modelling scenarios. These scenarios will be tested at three future timescales, using the PROMETHEUS probabilistic local weather data for the UK Climate Projections of 2030s, 2050s and 2080s, at 12 climatic regions within England as defined in SAP 2009 and under the current carbon intensive electricity grid and the 2030s and 2050s projected carbon reduction levels. The model input and output will be calibrated using empirical data sets and the modelled predictions will be verified against field trial data.

The findings of this study concern the impact that the additional service of cooling could have to the HP uptake and the National Carbon Plan to 2050 as well as the health and comfort implications in a future climate. This could have broader implications for the government’s low carbon and health policies. The work may be of interest to HP manufacturers and installers, policy makers and health professionals.