Sun, 03 May 2026 11:31:25 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299589#Comment_299589 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299589#Comment_299589 Tue, 10 Jan 2023 20:10:03 +0000 eniacs
Weve a 12'000L pool in the garden that is dormant in the winter. Its temperature slowly follows ambient, it will take weeks to get down to 5 deg and then weeks to go back to 10 deg too.

Basically Im thinking to use a heat pump to cool the pool water and heat the house. The heat input to the pool would be able to be PLC choosen, ie if the air temp is above pool water temp then run a fan coil and pump to "warm" the pool water from ambient air.

I know its a drastic solution to a simple problem of low COP but my mind keeps going back. Maybe its the engineering challenge.

Has anyone seen a similar project?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299594#Comment_299594 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299594#Comment_299594 Wed, 11 Jan 2023 15:50:18 +0000 Jeff B
https://www.vaillant.co.uk/homeowners/products/renewables-solutions/water-source-heat-pumps/?gclid=CjwKCAiA2fmdBhBpEiwA4CcHzbsATykJb3FDsyYXBV_taDtcbUA-mu-GyJ7GAeTLOf-vI3hxmO0wBxoC0EcQAvD_BwE

P.S. I have no connection with Vaillant - it just happened to be the first reference I came across via Google.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299598#Comment_299598 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299598#Comment_299598 Wed, 11 Jan 2023 17:10:17 +0000 philedge https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299601#Comment_299601 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17693&Focus=299601#Comment_299601 Wed, 11 Jan 2023 23:02:02 +0000 eniacs
I would have thought the pool wouldnt store much heat, even at 12k litres, its operating temp range will be low. Lets have a quick look how much it does store:

Lets say the "Charged temp" is 10 degrees C (the highest likely ambient temp in the winter, somtimes higher but usually 5-10deg here)
Then the lowest usable temp will be say -2 (you would never be able to take it below that as the fan coils to "heat" the pool would not have defrost available).

Energy of the water is: 12 x 13.5kwh = 162kwh. This would probably be enough to heat my house for 2-3 days during a very cold snap.

I suppose the problem with this is once the pool is very cold, no further heat could be extracted without freezing the fan coil heating. Probably a dead end here.]]>