Canadian Consulting Engineer
On the loo – #1, or #2?Engineering
Canada Mortgage and Housing Corporation has been testing a new type of toilet that allows the user to choose betwee...
Canada Mortgage and Housing Corporation has been testing a new type of toilet that allows the user to choose between two types of flush.
The dual-flush toilet was developed in the 1980s to cut down on water consumption. It uses six litres of water to flush solid waste, but only three litres to flush liquid waste.
The technology is mandated in Australia and Singapore, but is relatively new in North America, reports CMHC’s Research Highlights technical bulletin on their research.
The corporation funded research and field tests with 158 users to assess the dual-flush toilets’ performance and how well they might be accepted by the public.
They found that significant water savings were achieved. Flush volumes were reduced by 68 per cent in single-family dwellings and 56 per cent in office washrooms. and 52 per cent in restaurants. Most of the toilets replaced were older units that use 20 or 13 litres of water to flush. However, the dual-flush toilets also saved 26 per cent more water than did the efficient 6-litre flush toilets..
In terms of appearance, clearing solids and clearing liquids, more than 85 per cent of the toilets tested obtained ratings of either “good” or “satisfactory.” Sixty-six per cent of the people who tested them said they would defintely recommend dual-flush toilets to other.
A dual-flush toilet costs between $300 and $400. CMHC estimates that based on a simple payback period, single family dwellings would have a payback of approximately 8.5 years, or 5 years if the cost of water was increased to $1.70 per cubic metre.