What are System A, B and C installation methods?

Explanation of System A, B and C + schematics

There are three recognized installation methods listed under SAP, Systems A, B & C.

System A supplies preheated water to the cold inlet of the thermostatic mixer valve (TMV) and to the water heater/hot water source, this is the most efficient method. System B supplies it back to the cold inlet of the TMV only and System C back to the water heater/hot water source only.

System A:

A Balanced system that feeds both the water heater and shower

This is the highest efficiency method of installation and is usually used to maximise the impact of WWHRS on the Primary shower in a home (eg Primary ensuite shower)

A Recoup Pipe HEX installed as System A to a 9l/min Thermostatic mixer shower can reduce the overall energy required per shower use by around 55%

System B:

The Simplest method of installation in most cases. However, is also the least efficient of the three installation methods.

A Recoup Pipe HEX installed as System B to a 9l/min Thermostatic mixer shower can reduce the volume of hot water required per shower use by around 43%

System C: An unbalanced system that feeds the water heater only

Where a dwelling has a WWHRS system installed as System A or C, any additional WWHRS systems must always be installed as System B.

Recoup can help with the specification of WWHRS and appropriate System types. If you have any projects you would like Recoup's assistance with, please contact us.