In this article Anthony Barnett, Technical Marketing Manager at Armacell, looks at how a simple upgrade such as insulating pipe brackets in hot and cold water systems can eliminate a number of issues associated with energy loss and corrosion.
Caring about energy use in buildings is a key focus for both specifiers and clients, to such an extent that in the vast majority of cases high performance insulation and improved air tightness are specified. However, when it comes to the heating system, it is still common for new pipework to be installed using uninsulated pipe brackets, which can account for up to 50 percent of the heat lost in the system. This can, in some cases, negate the energy efficiency benefits of choosing an A+ rated boiler.
Pipe brackets represent a potential weak point in hot, cold and low-temperature systems. In hot systems, if the pipe is not thermally isolated from the bracket, significant heat loss can occur. For cold and low temperature installations, cold bridging occurs and results in condensation, which can cause rapid deterioration of the asset.
To put this into context, each uninsulated pipe bracket loses around £2.00 each year in wasted energy and, considering the number of brackets in a system, this can soon add up to a significant amount. Conversely, insulated pipe brackets cut total energy losses in the system by half, resulting in a payback of only a few months.
Hot and cold water systems
In a central heating system, the purpose of insulating pipework and fittings is to minimise heat loss, which is why they should be insulated as a matter of course according to the building regulations. A consequence of pipe brackets not being insulated is higher energy losses, which can be seen in figure 1 using a thermal imaging camera. The extent of this loss of energy can be significant, with thermal heat flow calculations for a 60°C hot water pipe in continual use showing a heat loss of 0.06 w/k per bracket (on a 26.9mm diameter copper pipe with a 27mm insulation thickness). This can have a major effect in total energy costs of running a building, especially where a large number of supports are used.
It is important, in some systems, to insulate cold water pipes and brackets in order to avoid condensation. This condensation occurs when the pipe is insulated but the bracket isn’t, which leads to thermal bridging and the risk of corrosion and expensive secondary damage. To prevent thermal bridging, direct contact between the pipe and its bracket should be avoided by using insulated pipe supports.
When choosing insulated pipe brackets for these applications, closed-cell elastomeric material, which has a high resistance to water vapour transmission and low thermal conductivity, is best able to protect against energy losses and condensation. In addition, our recycled, lightweight PET honeycomb core pipe support range offers better load capacity due to a new 100% recycled PET honeycomb core structure.
It is also worth bearing in mind that brackets should support the pipe without the insulation being compressed, which could compromise the insulation thickness required. A PET core achieves excellent load-bearing performance, prevents thermal bridging and delivers excellent material durability for maximum lifespan. The range of pipe supports are suitable for hot and cold applications and are suitable for pipes with operating temperatures ranging from 0 to +110 °C and available in thicknesses 13, 19 and 25 mm for pipe diameters of 10 to 89 mm.
An increasing number of heating engineers are choosing to use pre-fabricated elastomeric insulation supports such as Armafix X, with self-seal seams for quick fixing the insulation onto the pipe. The low thermal conductivity value and high water vapour resistance provides protection against energy losses and condensation whilst the load-bearing segments prevent the insulation material being compressed.
Support brackets in hot and cold installations represent a potential weak point. If cold pipework is not thermally isolated from the pipe bracket, thermal bridging occurs, resulting in condensation and subsequent corrosion of the fittings. Likewise, uninsulated brackets in a hot system result in significant energy loss. Specifying insulated pipe brackets that utilise closed-cell elastomeric insulation such as latest recycled PET materials avoids all these issues.
View AF/ArmaFlex Class O Product Entry