Heat Pump Association UK (HPA UK) has launched a new guidance document for heat pump installers describing the key considerations when insulating external hydraulic pipework of a monobloc air-to-water heat pumps (AWHP) located outdoors within the curtilage of a residential dwelling.
Endorsed by MCS, this new guide is the latest in HPA UK’s series of technical guidance documents developed with heat pump installers in mind. It comes at a time when non-compliant external pipework insultation is the number one non-conformity found on MCS audits. It aims to build heat pump installers understanding of why insulating hydraulic pipework of a domestic monobloc AWHP located outside is important in reducing system heat losses and contributing to overall efficiency of the system.
Previous publications from HPA UK include a Control Guide for Air-Water Heat Pump Systems and Guidance on Residual Current Device Selection for Heat Pumps – all of which are free to download from the HPA UK website.
Key features of the new guidance include:
Advice on good practice and considerations when insulating external pipework, clipping insulated pipes, insulating and sleeving pipework passing through walls and external plastic trunking,
Explanation of the common characteristics of external pipework, such as thermal conductivity, water vapour diffusion factor, UV resistance and emissivity factor,
Information on the relevant aspects of the latest Approved Document Part L 2026 to aid understanding,
Handy reference images indicating examples of good and poor practice.
By increasing general knowledge and awareness of the key considerations for external pipework insulation, the guide intends to improve on-site practices and support high-quality outcomes for consumers. In all cases, installers are encouraged to reach out to their chosen product manufacturer for their specific installation and maintenance advice. HPA UK expect to continue to review and update all guidance documents in line with evolving standards and practices as the market develops.
Commenting on the publication of the guidance, Nancy Jonsson, HPA UK technical consultant said: “HPA UK are keen to continue to support installation businesses to better understand regulations and standards. We hope that this new guidance will help demystify some of the key considerations when insulating external hydraulic pipework of a residential monobloc air-to-water and help to generally improve on-site practices, leading to overall better outcomes for consumers.”
Scott McBride, technical manager for heat at MCS, said: “MCS is proud to have worked with HPA UK on developing this guidance document for heat pump installers. We would like to thank HPA UK and the MCS Heat Pump Working Group who collaborated to bring together industry expertise to help drive continuous improvement across installation businesses. We remain committed to supporting certified installers in meeting MCS requirements, driving quality installations, and improving outcomes for consumers investing in heat pumps – giving everyone the confidence in these technologies.”
The full guidance document is accessible here.