Plumbing Africa August 2018 - Page 69

PROJECT 67 << Continued from page 65 The outdoor units located outside in a ‘hidden’ open room. The simple room thermostat controlling the room temperature in the kitchen. There were four in-wall distribution manifolds installed and connected to the underfloor water piping system. The Rotex Protect Integril polystyrene sheet system was installed, into which the PEX piping for carrying the hot and cold water was installed, which heats up the floor screed. A minimum of 50mm of screed was used on top of the 45mm pipe as well as high- and low-density polystyrene system. The two heat pumps can be controlled remotely via the Rotex mobile app. Which means the heating, cooling, and hot water temperature can be controlled from anywhere in the world! CHALLENGES The challenge is to ensure the integrity of the pipe after the underfloor water piping is installed and put under pressure whilst the floor screed is laid. The system has to remain under pressure until final handover, otherwise the pipes could be compromised and then the floor would have to be dug up and the pipes repaired. This was not the case by connecting the underfloor water system to the main water throughout the construction. ALL ABOUT EFFICIENCY The system reduces the cost of heating a house using electricity. This system was designed with a heat load of 60W/m 2 due to the design of the house, which has wall insulation, good north-facing orientation, and double glazing, compared to electrical underfloor wire heating that uses 100W/m 2 . The heat pump has a coefficient of performance (COP) of 3.5 and this gives a consumption of only 15W/m 2 . This means the system uses a quarter of the electricity required by the electrical underfloor heating. It is worth noting that the thermal store losses are only 1°C per 24 hours. In the end, everything came together well, and the client was “over the moon” with the end-result. PA August 2018 Volume 24 I Number 6