David Davis: “For decades we’ve designed and installed schemes and watched the stream of water produced by air conditioning units literally go down the drain”

UK: Two directors of a UK building services company have launched the world’s first cistern to use condensate from air conditioning units to flush the toilet.

Graham Kelly and David Davis of the Leeds-based G&H Group have created Encore (Environmental Condensate Recovery), which is described as the most environmentally friendly cistern available as it uses a free, sustainable water supply that until now has been drained to waste.

Based on data which says that with 15,119 rooms in 114 hotels currently being built in the UK, the company says that using Encore would save each hotel 1.92 million litres a year. And the water savings are even higher in hotter climates where more condensate is generated.

In the US, the 1,477 hotels currently in construction would save 4.7 billion litres of water a year and 2.4 billion litres for the 302 hotels in the Middle East, the company argues.

In another first for cisterns, it will also allow those specifying to secure two extra BREEAM credits and LEED points.

David Davis said: “For decades we’ve designed and installed schemes and watched the stream of water produced by air conditioning units literally go down the drain but not via the toilet.”

Encore can be used globally and is said to be ideal for those building and refurbishing hotels, villas, apartments, offices and anywhere with toilets and air conditioning.

The patented technology means the amount of water used in each flush is adjustable from six to 1.5 litres to meet different international requirements.

Encore holds 18-litres of water which is three times more than a conventional cistern but its dual-chamber design means it still fits like standard models. The bottom chamber holds 6-litres, which comes from the mains pipe. The upper 12-litre chamber is filled with air conditioning condensate.

When the toilet is flushed, the lower chamber empties and refills with condensate from the upper chamber. If there are multiple flushes close together or the air conditioning is not in use, the cistern is filled in the conventional way from the mains fed pipe.

If the toilet is not used for a while, surplus condensate is fed away.

Encore