The Great Hall, Kings College London, Strand Campus

Kings College London

Great HallPropelair toilets have been installed in washrooms serving The Great Hall at King’s College London’s Strand Campus. The Great Hall is used for a variety of purposes, including lectures, presentations, banqueting and receptions, and the washrooms are heavily used on a daily basis. Propelair’s robust design is well suited to high-usage areas, and the new toilets have provided the university with substantial environmental, financial and hygiene benefits. Following the success of the trial in The Great Hall, Propelair is now being installed in other washrooms across campus, including those serving The Maughan Library.


All four units are expected to save around 864,000 litres of water annually. This will result in a substantial reduction in carbon footprint: the energy saved by reducing the amount of water that needs to be supplied and waste that needs to be treated means an annual reduction in CO2 equivalents of 909kg (DEFRA conversion factors for greenhouse gas reporting 2015) – the same amount produced by 24 car journeys from London to Birmingham!


Each Propelair unit is expected to save around £445 per year, with a payback period of just 1.9 years through the water savings it generates. Over the next 20 years the 4 toilets are expected to save almost £36,000.


Propelair also provides washrooms users with a number of hygiene benefits. Every time a conventional toilet is flushed, particles of contaminated water become airborne, landing on washroom surfaces. Propelair’s unique displaced air technology efficiently removes all waste with one flush, reducing the spread of aerosolised germs by 95% and removing over 99.9% of waterborne contaminants. This helps to improve the health and wellbeing of staff, students and visitors using The Great Hall.

Metered Water Charge Flushes Per Day Current Flush Volume Annual Savings Payback
Water Financial
£2.06/m3 100 7.5 litres 216,000 litres £444.96 1.9 years

The Propelair toilets have been well received by washroom users, and comments from the guest book supplied in the newly refurbished washrooms include praise for both the technology and the university’s commitment to water saving and sustainability:

“Excellent initiative! Every step towards a more ecological KCL is worth supporting!”

“Great toilets! It’s important to save water; thanks for being environmentally aware. Thumbs up”.

“Great idea – it’s very practical and ecological. I hope you put this system in all the toilets!!”

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