South Africa and other countries on the African continent are running out of water! The volume of water unaccounted for (and unpaid for) is one of the highest in the world.
Reducing water loss starts a virtuous circle that leads to less water loss:-
- Water authorities increase their income.
- The extra income can be used to repair and maintain infrastructure, thus reducing water loss.
Pressure management at the network level is often suggested as a way of reducing losses. It’s effective but needs specialist investigation and design. And, pressure management equipment may need intensive maintenance.
On the other hand, domestic water use – bathrooms and kitchens – is often overlooked as an opportunity to reduce losses.
Maric offer a flow-control valve suitable for domestic use. The valve retails at about ZAR 1 000. Installation is very simple and at current water and electricity prices the payback period is less than a month. Here is the calculation.
Assumptions:-
- Family size: 4 people
- 4 x 10-minute showers per day: 40 minutes
- Shower consumption without Maric valve: 15 litres per minute, x 40 = 600 litres of warm water
- Average ambient water temperature: 16° C
- Average shower water temperature: 43° C
- Cost of water: 1 Kilolitre = ZAR 40.00
- Cost of electricity: ZAR 3.00 per unit (1 unit = 1 KiloWatt Hour)
- 1 KiloWatt Hour (KWH) heats 100 litres: 8.5° C (this is a known constant)
Savings in water use.
Assume a 7 litre per minute (l.p.m.) shower flow controller is installed. 8 l.p.m. will be saved, x 40 minutes = 320 litres per day. 320 x 365 days = 117,000 litres per year saved.
117 Kilolitres x R 40.00 per KL is ZAR 4 680 per year saved.
Savings in electricity consumption.
Lift in temperature required is 27°C (43°C shower temp, minus 16°C incoming temp)
If 1.0 KWH heats 100L by 8.5° C, therefore 1.0 KWH heats 31.5 litres 27° C
Therefore 3 714 KWH heats 117 Kilolitres (saving) by 27° C
3 714KWH x R3.00 per KWH = ZAR 11 142 per year saved.
Total annual savings per shower fixture.
Water savings: ZAR 4 680
Electricity savings: ZAR 11 142
Total savings: ZAR 15 822
The annual savings of ZAR 15 822 compares very favourably with the retail cost of the valve at around ZAR 1000.
The Maric flow control valve was designed in Australia. They’re manufactured in South Africa. They maintain a fixed maximum constant flow rate automatically. They’re often used to save water in homes, hotels, and commercial buildings.
Typical applications include:-
- Showers
- Basins
- Kitchen sinks
- Laundry troughs
- Drinking fountains
- Toilet cisterns to prevent “continuous flush” if the fill rate is too high.
- Water heaters to ensure that instantaneous heaters reach their advertised temperature.
With the critical status of water supply in South Africa and the African continent, this type of intervention is of utmost importance and sponsored by the people.
