Green Building Forum - Waste Water Heat Recovery Tue, 19 Dec 2023 05:50:36 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178550#Comment_178550 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178550#Comment_178550 Mon, 24 Jun 2013 19:39:00 +0100 Ed Davies Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178551#Comment_178551 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178551#Comment_178551 Mon, 24 Jun 2013 20:00:07 +0100 DarylP ]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178553#Comment_178553 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178553#Comment_178553 Mon, 24 Jun 2013 20:35:38 +0100 barney
Heating system fluid is usually far more contaminated than shower water - at least a Category 3 fluid - and no one worries about that when the filling loop is left connected and system pressure exceed MCWS pressure

Regards

Barney]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178565#Comment_178565 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178565#Comment_178565 Mon, 24 Jun 2013 22:09:01 +0100 SteamyTea ]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178572#Comment_178572 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178572#Comment_178572 Mon, 24 Jun 2013 23:47:13 +0100 djh Posted By: SteamyTeaBut with electricity at 0.18p/kWh it is a saving of £67/annum making the payback 7.5 years if the unit is £500.
I hope that nobody on here believes that using mains electricity resistance heating is a way to justify one of these devices? Get a more efficient water heater instead.
Becomes marginal there, but as you rightly say, reduce the usage only saves you money.

I think that's backwards. Reducing usage saves water, energy and money. These devices may or may not save money and energy but definitely don't save water.]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178584#Comment_178584 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178584#Comment_178584 Tue, 25 Jun 2013 09:05:45 +0100 Seret Posted By: barneyA shower in a domestic dwelling is generally a Category 3 fluid - a simple backflow device like a double check valve would satisfy WRAS requirements.

Regards

Barney

Thanks Barney. That's so easy I'll stick one in pronto.

I fitted my unit yesterday. Seems to be doing something, in the shower I took yesterday I was able to turn the shower down quite a bit from the usual setting to get the same temperature. I haven't got the shower instrumented, so I'll have to wait for a few weeks gas readings to see if there's a noticeable impact on usage.]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178637#Comment_178637 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178637#Comment_178637 Tue, 25 Jun 2013 18:21:55 +0100 RobL In a nutshell, shower water is centrifuged to clean it a bit, it's UHT heated, and mixed with a third extra fresh water before going to the shower head. They claim to re-use 70% less heat & water, for the actual same shower experience.

http://www.recyclingshower.com.au/]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178716#Comment_178716 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178716#Comment_178716 Thu, 27 Jun 2013 07:36:10 +0100 SilverSpray I've got more than one shower, a bath, a washing machine, so after seeing quite a few commercial options I'm going for the "heat squirrel". It's a 120 litre holding tank for any "waste" hot water. Incoming cold water to your heating system / hot water tank, goes through pipes inside this "heat squirrel' tank, so it should pick up some of the heat from the hot water. It also means 120 litres of water is held inside your house before it heads away.

Some information on what I've found on this topic, and the heat squirrel is at http://www.silverspray.co.uk/2012/03/26/ecobuild-waste-water-drain-water-shower-heat-recovery/

By holding the hot water, there is more time for the heat transfer to any incoming cold water, especially any that sits in the coil inside the heat squirrel.
Hopefully this 120 litres of water is regularly self flushing as “grey water very quickly turns manky when stored, even for short periods.”]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178733#Comment_178733 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178733#Comment_178733 Thu, 27 Jun 2013 09:33:04 +0100 Ed Davies
http://www.theyellowhouse.org.uk/themes/heatwat.html#h14]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178830#Comment_178830 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178830#Comment_178830 Fri, 28 Jun 2013 09:52:01 +0100 SilverSpray Posted By: SeretAny further info on that Heat Squirrel? I've contacted the company, but just wondering if you had done any research.

Was planning on building a heat recovery tank into my extension plans, had intended to build my own but I must admit a premade one does appeal to my lazy side.

Seret,
I've spoken to them and another company who has installed a heat squirrel. The company that installed it for a client of theirs said they had a happy client. There doesn't seem to be much more info, but I don't know what extra info you'd want ?]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178860#Comment_178860 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178860#Comment_178860 Fri, 28 Jun 2013 16:04:13 +0100 SteamyTea Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178896#Comment_178896 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178896#Comment_178896 Sat, 29 Jun 2013 09:35:29 +0100 SilverSpray
Seret: I don't think the Heat Squirrel has any controls. It works by virtue of the inbound cold mains water flows through the tank of 120 litres of your waste hot water. By there being a long coil route through the Heat Squirrel tank there is a long surface area and time (both matter) to transfer heat to the cold mains water.
I've added the schematic and installed Heat Squirrel images I had to the page.
See http://www.silverspray.co.uk/2012/03/26/ecobuild-waste-water-drain-water-shower-heat-recovery/#heat-squirrel]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178897#Comment_178897 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178897#Comment_178897 Sat, 29 Jun 2013 09:44:31 +0100 SilverSpray
- They are about £399 (not installed). The heat squirrel has a 120 litre capacity.
- Can the waste water input be regulated so that only waste water that is warmer than the water in the heat squirrel is let in to it? I don't see why a temp sensing valve can't do this.
- It seems that for a shower, the recoupenergy solutions will be the most efficient, but for the whole house, and the total cost, a single heat squirrel could be best.]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178905#Comment_178905 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178905#Comment_178905 Sat, 29 Jun 2013 11:09:37 +0100 SteamyTea Posted By: SilverSprayWho was the Thermodynamic panel fitter ?
www.greenairsouthwest.co.uk

They have a nice oil price chart, shows that it is currently $102.10/barrel and going down. Iam sure a bit of code could be written to only show it when it is going up.]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178921#Comment_178921 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178921#Comment_178921 Sat, 29 Jun 2013 18:30:47 +0100 Seret Posted By: SilverSpray
- Can the waste water input be regulated so that only waste water that is warmer than the water in the heat squirrel is let in to it? I don't see why a temp sensing valve can't do this.


This seems crucial to me, but it doesn't look like any such thing is fitted. That schematic does show a "temp sensor pocket", but it's not clear if that's for anything in particular. I'm also a bit sceptical of the way they show something like a washing machine or a dishwasher feeding it. Unless you have your dishwasher upstairs I can't see that working.]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178925#Comment_178925 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=178925#Comment_178925 Sat, 29 Jun 2013 19:40:27 +0100 djh Posted By: SilverSprayCan the waste water input be regulated so that only waste water that is warmer than the water in the heat squirrel is let in to it? I don't see why a temp sensing valve can't do this.
I would guess valves are designed for clean water, not for water with various kinds of goop in it. It's bad enough cleaning out a trap, how would you clean a thermostatic valve?]]> Waste Water Heat Recovery http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=277569#Comment_277569 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10787&Focus=277569#Comment_277569 Wed, 25 Dec 2019 12:59:57 +0000 wholaa