Lower DHW temperatures will reduce heat network costs

New guidance is likely to allow lower heat network operating temperatures, thus helping to minimise heat losses, lower risk of overheating, maximise contributions from heat pumps and consequently deliver better carbon performance.

To date, lowering hot water temperatures has been hindered by some building warranty providers which has a requirement for delivery of hot water at the kitchen tap at a temperature of 55°C. This means that flow temperatures from the Energy Centre are likely to need to be around 70°C, limiting either the heat pump efficiency or their contribution to the heat mix.

The industry is moving towards allowing hot water to be delivered at around 50°C at the kitchen tap within 45 seconds, which is in line with HSE guidance for the control of legionella. This allows the flow temperature from the Energy Centre to be reduced to around 60°C. This is welcomed as it allows heat networks to be designed sympathetically to the heat pump source which always favour lower temperatures.

Further guidance and confirmation on this from leading institutions is due to be released later this year.