NET ZERO SYSTEMS & SOLUTIONS


www.heatingandventilating.net


Heat pumps power low-carbon future for prison estate


Aermec’s Barry Whyler explores how heat pumps help reduce emissions for HMP Eastwood Park


Left: Airmec regional sales engineer Barry Whyler


building management system (BMS) upgrade, and the installation of new double-glazed windows. Delivery of these practical steps are designed


Gloucestershire’s HMP Eastwood Park. Not dissimilar to small towns, prisons operate


P


risons consume substantial amounts of energy because of their 24/7 functionality, security, and infrastructure. But with aging


estates and many built decades ago they have legacy lighting, insulation, HVAC, and control systems that can be expensive to run, maintain and diffi cult to retrofi t. This creates a structural problem: high


operational costs, carbon output, and limited fl exibility to modernise without disrupting security. But these pressures make sustainability an environmental, strategic, and operational concern. Energy effi ciency is a core operational priority. The prison service managed by the Ministry of Justice (MOJ) is consistent in its direction of travel and is assisting the prison estate to undergo a signifi cant transformation to cut CO2 emissions and improve the effi ciency and sustainability of facilities. The latest prison to implement targeted


measures in support of the government’s Net Zero goals is


24/7, are densely occupied and consume signifi cant amounts of energy. A key challenge is the ageing condition of much of the prison estate which can make retrofi tting challenging and costly. Two of HMP Eastwood Park’s prison blocks,


originally constructed in the 1960s, are undergoing upgrades to reduce energy costs and carbon emissions. This initiative focuses on installing Aermec heat pumps and improving insulation at the closed category prison in South Gloucestershire for up to four hundred women aged eighteen and over. Outdated gas boilers are being replaced


with Aermec heat pumps thanks to £3 million secured in funding from the Ministry of Justice (MOJ). Prisons are complex public sector sites and carbon intensive. In addition to installing air source heat pumps, additional measures will also be implemented as part of the decarbonisation programme. These include improved roof and cavity wall insulation, an upgraded pumping system,


to reduce energy consumption, lower operational costs, and diminish the prison’s carbon footprint. Despite operational, technological, and fi nancial challenges posed by aged buildings combined with the historical signifi cance of many buildings, prisons like HMP Eastwood Park are undergoing energy effi cient upgrades. HMP Eastwood Park’s eff orts form part of a nationwide initiative that aims to reduce the carbon footprint of public sector buildings which sets and example and refl ects the MOJ’s commitment to environmental responsibility. It is anticipated that the prison will benefi t from


lower carbon emissions due to improved energy use. By installing air source heat pumps, the prison will also reduce overall energy costs. These changes contribute to meeting the government’s goal of net-zero emissions by 2050 and support long-term sustainability within prison estates. Four reversible air source heat pumps (ASHPs)


are being installed using R32 refrigerant, a low GWP (GWP of 675) which reduces the environmental impact of HVAC systems, with extensive attenuation packages to reduce the operational noise levels and provide acoustic comfort in the complex. Although designed for dual functionality,


to provide chilled water for cooling and high temperature hot water, the units will be providing heating only. There is a cascade arrangement with the NRG ASHPs producing a water outlet at no more than 45ºC. This source water feeds Aermec’s WWB units where heat is extracted from the source water. The source water then returns to the ASHPs at 40ºC and the ASHPs continue to raise the water temperature back up to 45ºC. The WWB units will concurrently output higher


temperature water (the maximum is 80ºC) that provides the heating. The output temperature was designed to provide heating at 78ºC/80 ºC. Four of the WWB units are in one prison block due


to a larger size and heating demand whereas three further units are in another smaller building where three WWB 900 units are suffi cient. The main use of the hot water generated is for central heating but also DHW for showers, cleaning, and other ancillary functions. Aermec developed the irreversible (heating


only) WWB 900 water-water heat pump units for this project with the aim of guaranteeing high


14 April 2026


DOWNLOAD THE HVR APP NOW


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32