The goal of thermally insulating building services systems is to reduce heat transfer, which saves energy and helps to ensure the efficient operation of building services.
Across the UK and Ireland, the insulation of building services is governed by applicable building regulations. In each case the guidance references BS 5422, which describes the minimum provisions for the insulation of pipes and ducts serving space heating, hot water, chilled water and ventilation systems, in both new build and existing properties.
The standard
BS 5422: 2023 provides methods for specifying thermal insulating materials needed on pipes, tanks, vessels, ductwork and equipment for certain defined applications and conditions within the temperature range –40°C to +700°C. It gives guidance for designers, specifiers, contractors and manufacturers of thermal insulation in the HVAC sector, supporting compliance with building regulations. While the thicknesses stated in BS 5422 relate to generic insulation materials, manufacturers often use the stipulated performance criteria to create thickness tables that are specific to the performance of their products. For more information please see the ROCKWOOL Guide to BS 5422:2023.
Ensure to cover all parts of the system
Pipe supports and fixtures are an important part of any building services system, yet these can be overlooked when it comes to thermal performance. It is here where thermal bridging can become a problem.
Pipe support systems require a load-bearing material to be installed between the support and the pipe surface, and as per the guidance in BS 5422, this material should also be insulating.
The standard states that load-bearing insulation should be used between the pipes and any support or fittings to avoid a gap in the insulation caused by compression of the material. Other structural elements, for example, stiffening rings, should be insulated externally to reduce thermal bridging. Traditionally, pipe supports have included wooden block inserts. While these provide sufficient load-bearing capacity, wooden supports lack any substantive thermal benefit, and as a combustible material could compromise fire performance. More recently however, insulated pipe support inserts made from non-combustible stone wool have been introduced, offering proven thermal insulation as well as fire protection.
