Domestic Hot Water
Electric Heating solutions for Domestic hot water (DHW)
Access to hot water is nowadays an obvious standard for multifamily buildings. We have hot water available whenever and wherever needed – and preferably immediately. The latest building regulations (ASHRAE 188-2015, IEC 62395-2 and CIBSE TM13) demand domestic hot water systems to ensure best comfort and efficiency as well as the Legionella control measures. This means that each centralized building water system should be protected against Legionella not only via efficient filtration and disinfection but also by maintaining water temperature within the control limits in the legionella’s risk management plan.
The electric heating system for domestic hot water maintains water supply at the required temperature level and provides appropriate disinfection to suppress the Legionella bacteria.
Moreover, the pipe tracing systems ensure hot water in all taps and savings when a circulating pipe system is unnecessary. They also reduce water waste as you can get hot water immediately. The solution can be used in domestic hot water (DHW) systems supplied by the Low temperature district heating (LTDH), which is a cost and energy efficient way of building water supply in urban areas.
The initial investment of DHW system without circulation means appx. 50% less pipes, insulation, valves, and pumps to be installed since no return pipes and insulation are required. This means also that you don’t need additional space for return pipe, which gives more room in service ducts.
The heating cables provide power only where needed adapting output according to the ambient temperature. Also, less pipes and smaller boilers requirements for the DHW means less heat losses in the system.
The Domestic hot water systems consist of heating cables, electronic thermostats, and installation accessories.
The DEVIreg™ Therm Control DHB 330 is designed for controlling DEVIhotwatt™ self-limiting heating cables used for temperature maintenance inside pipes. The temperature can be regulated within a range of 35 °C to 70 °C.
Recommendations for Domestic hot water installation
Domestic hot water systems maintain water supply at the required temperature level and provides appropriate disinfection to suppress the Legionella bacteria:
• Multi-family buildings
• One family houses for external isolation
• Hotels & Commercial buildings
General design principles aim to provide uniform water temperature, which should also avoid temperatures enabling the Legionella growth. The general recommendation for DHW is to maintain the heat source temperature between 50-60 °C (IEC 62395-2:2013).
Application manual: Domestic hot water
This design guide presents DEVI’s recommendations for design and installation of Domestic Hot Water system. It provides guidance for a heating cable layout, electrical data and system configurations.