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Raychem HWAT Heat Trace System Meets the New CIBSE Guide G
- Published: Thursday, 29 May 2014 16:51
The guide recommends that secondary circulation (or trace heating) should be provided when the length of hot water pipework and the volume of the water that the pipework contains become such that it would take an unreasonable length of time to draw off the cool water.
Raychem HWAT is the safe way to supply instant hot water from centralised production in modern building design. Single pipe direct hot water service incorporating smart self-regulating heating cable technology provides a proven, creative, and precise method of delivering constant hot water temperature throughout an entire network, without the need for recirculation. Furthermore, dead legs are eradicated and pipes are traced to the pipe end meaning hot water is delivered to every draw-off point.
Traditionally, water temperature has been maintained in pipe networks by continuously pumping the water around the distribution system and recirculating it back into the boiler to be reheated. With HWAT, removing the need for recirculation significantly reduces the installed heat losses.,
The inherent safety benefits of HWAT are obvious; with no dead legs, there are no untraced pipes where water temperatures can drop to near 37°C – legionella’s ‘ideal temperature’. In addition to this safety feature, pipework networks are reduced in length (as there is no need for recirculating pipes), space is saved for other utilities or services (or even for the installation of larger insulation on hot water pipework which in turn saves energy by preventing heat loss). Boiler sizing can be recalculated and often reduced as there is no need to re-heat the incoming “return” water. This means the overall system energy efficiency is significantly increased, there are lower heat losses through short pipe runs, continuous flow pumps are not needed and optimal boiler sizing reduces energy consumption.
CIBSE Members can find the guide at: http://www.cibse.org/knowledge/cibse-guide/cibse-guide-g-public-health-and-plumbing-engineeri