Green Building Forum - rainwater harvesting and cost to run pump Sun, 31 May 2026 02:55:25 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 rainwater harvesting and cost to run pump https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29634#Comment_29634 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29634#Comment_29634 Fri, 08 Aug 2008 22:31:22 +0100 liberteeen rainwater harvesting and cost to run pump https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29638#Comment_29638 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29638#Comment_29638 Fri, 08 Aug 2008 22:52:14 +0100 ted rainwater harvesting and cost to run pump https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29681#Comment_29681 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2313&Focus=29681#Comment_29681 Sat, 09 Aug 2008 14:19:19 +0100 mike7 A more reasonable efficiency would be 5%. Higher is possible but hardly worth the effort.

The main thing is to choose a pump with a bit more max. head than your 6m, say 8 or 9m. You don't need a high a flow - you wouldn't want more than the overflow could cope with if anything went wrong - and it's likely that most of the centrifugal pumps around giving this sort of head will be working at the lower end of their quoted flow rate. 200w - 300w should be plenty, and deliver something like 10 or 15 litres a minute.]]>