Tapping into Waste Water Heat Recovery

Briary Energy, being a solutions company, are always striving to find innovative ways of reducing energy use in the home.

One such route we have investigated is Waste Water Heat Recovery Systems (WWHRS). Occasionally, when quoting this technology to clients, we are asked to explain the system, so thought I would use this forum to give a conclusive explanation, and highlight the benefits.

The WWHRS is a copper pipe heat exchanger, consisting of three tubes. Hot waste water from the shower drains away through the inner bore of the heat exchanger. Simultaneously, cold water from the mains is delivered between the inner and outer copper tubes, heating it to around 27°. This ‘pre-warmed’ water is then delivered to the system or combination boiler, as well as the shower taps cold water feed, thereby generously relieving strain from the boiler. The WWHRS will reclaim 60% of heat that otherwise would have been lost down the drain.

Showers are the biggest consumers of water in the homes, using 25% of the total usage. This accounts to over two billion litres of water that Britons are showering away each day, so is a source that would be a waste not to ‘tap’ into.

There are several variations of Waste Water Heat Recovery available, the most common being Showersave Recoh-Vert – see diagram below. This, and other systems, are recognised in the SAP Product Character Database, and can offer 5-7% reduction in Dwelling Emission Rates, depending on size of building.

Advantageously, compared to alternative technologies such as solar; it works to same capacity all year round, and isn’t aspect dependant. It will reduce energy bills, and help to reduce fuel poverty. It is simple to install, maintenance free, and the life span of the technology is expected to be in excess of over 20 years.

It is a technology which is constantly gaining momentum, with many developers are including it in their specification. Sales have now hit the 50,000 mark across Europe, with 5,000 of these being in the UK.

With a cost in the region of £600, it offers a financially and environmentally viable solution to achieving Part L1a, and enhancing upon Target Emission Rate in SAP.

Nick Barker – Briary Energy

WWHRS Ricoh-Vert
WWHRS – dissected to demonstrate functionality