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Rainstream Rainwater Harvesting Tank Sizing Guide


Office tank sizing

The below table gives an indication of tank sizing for a typical office. The table is based on the average office water consumption of 50 litres per person, per day, which is equal to 31 litres of non-potable demand. The below table can be used to give an approximate tank sizing based on the building occupancy and its associated demand. The information below is a guide only and Polypipe WMS recommends a full assessment must be carried out for individual sites. Please visit www.polypipewms.co.uk to download an assessment form.

Tank Size calculations for Commercial use
Number of People Tank Size (ltr) Number of People Tank Size (ltr)
1-4 1500 65-70 30,000
5-6 2500 71-85 36,000
7-8 3000 86-94 40,000
9-11 4500 95-105 45,000
12-14 5500 106-117 50,000
15-18 7500 118-126 54,000
19-21 9000 127-140 60,000
22-24 10,000 141-152 65,000
25-28 12,000 153-165 70,000
29-32 13,600 166-186 80,000
33-36 15,000 187-211 90,000
37-43 18,000 212-232 100,000
44-48 20,000 233-260 110,000
49-54 22,500 261-300 120,000
55-64 27,000 For number of people over 300 please contact Polypipe WMS as we can provide tanks upto 300,000 ltr
Rainstream Rainwater Harvesting Tank Sizing Guide