CIBSE AWARD WINNER | ENCORE CISTERN BUCKING THE CISTERN The Encore cistern diverts air con condensate from a waste pipe to the toilet flush a brilliantly simple idea thats won a CIBSE energy-saving product award. Amanda Birch reports 1 2 3 4 5 6 Soil and waste pipe Condensate connects straight into Encore cistern Air conditioning unit Encore cistern Mains cold water back-up water supply verflow to drain. Trap built into Encore cistern A revolutionary toilet cistern that uses condensate from air conditioning units for flushing could save millions of litres of water in drought-stricken areas of the globe. The Encore, developed by Leeds-based renewable innovation company The Green Futures Initiative, won the Energy Saving Product or Innovation of the Year category at this years CIBSE Building Performance Awards a prize that recognises building services solutions that reduce the amount of energy used in buildings. The judges described the product as a really innovative solution that employs a range of potential applications, [and] that is suitable for retrofit and new-build. According to David Davis, director of The Green Futures Initiative, Encore is the only cistern of its kind, as conventional ones use mains drinking water. When he and his colleague, managing director Graham Kelly, first had the idea for their cistern five years ago, they were surprised that a similar product didnt already exist. Our background is in M&E building services and we had been asked by a supermarket chain how to get rid of the waste condensate from its refrigeration units, says Davis. We decided we should try to find a way to use the waste water for flushing toilets. Rigorous research and collaboration with plastics engineers and designers resulted in the Encore, which is now manufactured in The 2020 shortlist will be Doncaster. Unlike a traditional toilet, announced in November at www.cibse.org/bpa which empties the cistern with each flush, the Encore stores the condensate by using a dual-chamber, 18-litre tank, which is three times bigger than a conventional cistern. This enables multiple flushes before drawing on the mains-fed backup. The bottom chamber of the cistern is adjustable in half-litre increments and holds between 3.5 and 6 litres, to meet different international standards. When flushed, condensate in the bottom chamber empties and a communication valve opens, allowing stored condensate from the top, 12-litre chamber to be released into the bottom for the next flush. The upper chamber continues The Encore comes fully to be topped up with the air conditioners assembled and is easy to install and maintain waste water. If there is high demand, with many flushes in quick succession or the air conditioning is not in use the cistern can be filled using the mains water supply. The Encore cistern, which uses plastics that can be ground up and reused for other products, comes fully assembled with an additional flush pipe and related washers, Encores dual-chamber and can be wall- or frame-mounted. It can be tank is 3x bigger than a operated by a single pneumatic flush button conventional cistern or a wave plate, and, apart from washing out a small filter tray once a year, little maintenance is required. We didnt want plumbers to have to undertake additional training to fit it, says Davis. It had to be like installing an ordinary concealed cistern, the only difference being an extra filling connection to allow for a separate water source from the air-conditioning unit. The Encore can be specified for new-build and retrofit projects, and Davis anticipates it being suitable for a wide range of building types, including hotels, offices, restaurants, apartments and www.cibsejournal.com October 2019 65 CIBSE Oct19 pp65-66 Encore Cistern.indd 65 20/09/2019 16:16