With full domestic rainwater harvesting systems, there are two key considerations: 1) Size of the holding tank and 2) Which type of control system, direct pressure or header tank.
1) The size of the holding tank is calculated using the amount of water that is likely to be collected from the roof (roof area and average local rainfall) and working out the demand for non-potable water in the property (WC, washing machine and outside tap). As a rule of thumb, you need approximately 800-1000 litres of installed capacity per person. So a 2,600 litre tank would be suitable for a 3-4 person household. Prior to ordering, please email email@example.com or telephone 0845 1250 000 for assistance, we can provided a calculation for you. NB it is worth noting that the sizing of a rainwater harvesting system is not an exact science, but it narrows down the requirement to one or two sizes.
2) Our control systems either direct pressure or via a header tank (indirect). Both variations are cost the same, where possible we would recommend the header tank system, but equally, the direct pressure systems are very effective, if your project is unable to use a header tank.
A link to download the installation manual is provided at the bottom of each individual product page listing. This will be very helpful when considering the suitability of our system for your project/situation. Should you need any help or advice pre-purchase or during installation, please call 0845 1250 000 or email firstname.lastname@example.org.