HPA UK publishes guidance on heat pump pipework insulation

UK – HPA UK has published new guidance to help installers improve external pipework insulation on domestic air-to-water heat pumps, addressing the most common non-conformity identified during MCS audits. Published on 7 October and endorsed by MCS, the document provides practical advice on reducing heat losses, protecting insulation from the elements and meeting relevant Building Regulations requirements.

Improving installation standards

The guidance focuses on external hydraulic pipework serving monobloc heat pumps, where inadequate insulation can increase heat losses and reduce system efficiency.

Installers are advised to insulate flow and return pipes separately, seal joints and exposed edges, and protect insulation against moisture and UV exposure.

The document also covers the treatment of fittings, valves and pipe supports, warning against compressing insulation when securing pipework.

Trunking and weather protection

HPA UK makes clear that external trunking is not a substitute for insulation. Pipework enclosed within trunking must still be fully insulated, with sufficient space to prevent compression.

The guidance also highlights the importance of preventing water ingress and selecting materials suitable for prolonged outdoor exposure. Some insulation products may require additional UV protection.

Supporting regulatory compliance

Developed to support compliance with Part L of the Building Regulations, the document provides practical installation advice beyond the detail contained in Approved Document L.

It applies to external pipework on domestic monobloc air-to-water heat pumps. Commercial premises, high-rise buildings and other more complex installations fall outside its scope.