Asking the right questions
Selecting the appropriate insulation is critical for heat pump systems to cope with environmental conditions and maintain efficient heating performance. Here, Tom Merton, Technical Manager at Armacell UK, looks at why this approach is best implemented for external pipework.
Optimising the efficiency of a heat pump system relies on selecting the right insulation for outdoor pipework. The insulation not only needs to protect the pipes from environmental factors – wind, rain, frost, UV degradation – but also ensure that the system operates at optimum efficiency over the long-term.
This is particularly important with heat pumps because system efficiency relies on transferring heat from one location to another. Without adequate insulation, the overall efficiency can be significantly compromised, leading to increased energy consumption and higher operational costs.
Appropriately specified insulation such as elastomeric closed-cell material can provide an effective solution because it delivers exceptional thermal performance whilst addressing the environmental challenges of modern building and industrial applications. Principally, it is the closed-cell structure of elastomeric materials which creates an impermeable barrier that prevents moisture ingress. This moisture resistance capability ensures that the insulation maintains its thermal properties over time, preventing the degradation that can occur when water vapour penetrates conventional insulation systems.
When it comes to selecting closed-cell insulation for outdoor heat pump pipework, it depends on whether it is for a new installation or retrofit of existing pipework.
Benefits of pre-insulated pipes
Pre-insulated pipes, such as ArmaFlex Fastlink, are elastomer insulation materials designed specifically for new heat pump installations. These kinds of pipes come with built-in insulation, which simplifies installation and, because it is applied in a quality-controlled production environment, ensures consistent thermal performance.
Being pre-insulated also means the pipes are ready for immediate use, reducing installation time and labour costs. It’s worth checking that the pre-insulated pipe lengths offered are suited for space-saving installations so you have the option of installing the heat pump unit close to the house wall, which is necessary if it is not possible to lay the pipework underground.
If you choose pre-insulated corrugated pipes, it will provide you with good bending capacity and flexibility, making it possible to implement individual solutions for the choice of installation location of the heat pump’s outdoor unit. For quicker installation, check they are supplied with appropriate quick couplings.
Insulating existing heat pump pipework
For existing heat pumps that require an upgrade to external pipework, UV-resistant options like HT/ArmaFlex or ArmaFlex Tuffcoat can be used. These flexible elastomer insulation materials have exceptional resistance to UV radiation and high temperatures. In addition, the closed-cell structure and low thermal conductivity of these materials keeps water vapour from diffusing in and reduces energy losses, protecting and optimising the efficiency and lifetime expectancy of the installation. While remaining flexible at application temperatures of up to 150°C, being dust and fibre free and easy to install without special tools makes the material a preferred choice with installers. It’s also beneficial if the product doesn’t need additional jacketing, does not degrade in sunlight, and withstands accidental oil contact.
Due to the thermal properties of these kinds of elastomer insulation materials, the heat flow from the air source unit to inside the building is kept at its utmost minimum. The evenly spread, homogenous and long-term stable closed-cell structure prevents convection heat loss, ensuring very low thermal conductivity of the insulation material. Retrofit is an approach that is often preferred with contractors and their customers because it can be more economical than replacing the entire system.
Installation best practices
Proper installation of insulation is crucial for achieving the desired performance. It should fit snugly around the pipes to prevent gaps that could lead to heat loss. One of the best ways of achieving this is the use of appropriate adhesives or tapes to secure the insulation in place.
Special attention should be given to joints and connections, as these areas are prone to heat loss. Use UV-resistant tape to seal any gaps and ensure a continuous layer of insulation. Moisture can also compromise performance, so it is important to ensure that the insulation is installed in a way that prevents water accumulation, particularly in outdoor settings.
The way forward
Selecting appropriate insulation for external heat pump piping is crucial for optimal long-term performance and energy efficiency. Whether selecting factory-insulated pipes or adding insulation to existing pipework, both using UV-protected elastomeric materials, understanding your system requirements will inform your selection.
By evaluating crucial elements like pipe dimensions, climate conditions, and ease of installation, you can help ensure your clients’ heat pump systems deliver reliable service over time.
