Domestic Hot Water system

Anti-bacteria measures

Problem:
A major element of any Domestic Hot Water system is the abilitiy to minimize any bacterial or Legionella risk.

The risk occurs whenever potable water is stored below temperatures of about 60°C. The longer the water is at the risk temperature the higher the likelihood of the bacteria growing.

One way of minimizing the risk is to ensure that the temperature is periodically raised to, say, 70°C for a short period. This tends to create another layer of complication to the design of a system as well as having to use the most expensive heat source to achieve it.

Solution:
Our preferred solution is to avoid storing the potable water entirely. This can be achieved by using a heat exchanger, either internally within a thermal store or if a higher flow rate is required then an external plate heat exchanger can be used. This is the same principle as a combi-boiler.

This can be coupled with a secondary circulation system if the installation dictates.