38%
Total Average Water Savings
ROI 2.4
Return on Investment in months
7.6 tons
CO2 Savings per year
Background
Snyggatorpskolan is an elementary school in southern Sweden with 572 students and 48 teachers. The school has several different buildings that houses over 100 bathrooms, a gymnasium with showers and a kitchen that caters to nearby schools in the vicinity.
Implementation
Installation of Altered Single Flow Dome nozzles and signage in 50 bathrooms over 2 buildings in August 2019. Evaluated buildings include the catering kitchen, classrooms and bathrooms. The gymnasium with showers was excluded from the project. The project has been evaluated through a comparison on total water use in the evaluated buildings over a period of 4 months.
Results
Year on year comparisons on Total Water Use in the evaluated buildings have shown savings of between 30–44% with an average Total Savings of 38%.
The share of hot waterused in bathroom taps was estimated at 30%. This results in Energy and CO2 savings of 12,859 kwh and 7.6 tons of CO2 per year. Based on utility costs for water of 2.9 EUR/m3 and 0.22 EUR/kwh, direct ROI for the project was 2.4 months.
A positive side effect of the project was that water damage due to vandalization (i.e paper towels that are put in the sink with the faucet running to over-flow the bathroom) was reduced from 5-6 per term, to zero during the project period. These water damages normally incur a cost of EUR 3.000 –10.000 event. Taking these savings into account, the payback time for the project was less then a month, and total savings for 1 year is calculated to EUR 76.900.