We have bathroom which is very distant to the hot water heater and the hot water takes about 2-3mins to arrive. I have heard of devices to recirculate the cold water in the hot pipes back into the system until the hot water reaches the faucet. I am told Reece has one. I have looked on the web but mostly been able to find systems which keep the hot hot all the time, which doesnt seem particularly sensible to me. (autocirc by carhil) Does anyone have any experience or comments on this topic? thanks
cold water recirculation(47 posts) (31 voices)
A few years ago I saw a system that cost over $1,000 to do this it seemed to have no return economically.
There may be different systems with different prices now.Posted Thursday 7 May 2009 @ 4:24:19 am from IP #
"Cold water recirculation: - you probably mean "hot water recirculation" OR "getting the cold water out of the hot water line & not losing the water".
I am right in the middle of looking into this myself. Current options seem to be Grudfos & Metlund. Trying to find which of their several options is the way to go is not easy. Will let u know how I get onPosted Thursday 7 May 2009 @ 6:53:15 am from IP #
One of my nearby clients installed such a system in his house, where the occasionally used guests' bathroom is a long way from the solar tank, and reported that it worked well. I don't recall the brand or costs but I'll call him tomorrow and find out.
He's on tank water where the water waste of waiting for hot could be an issue.
The other system of continuously circulating hot water is used in hotels etc, where guest convenience is a bigger priority than the energy bill.Posted Thursday 7 May 2009 @ 9:32:46 am from IP #
Thanks, I look forward to hearing more. I phoned Reece about their system (chillipepper) to find it has been discontinued. They suggested something by Rinnai, I think it was called smartstart but couldnt find out more about it today. Have emailed rinnai to ask them for more info. The only grundfos system I found was the one which punts the cold water from the hot pipe as soon as it goes cold, although you can set it on a timer.Posted Thursday 7 May 2009 @ 11:13:03 am from IP #
About $1200 installedPosted Thursday 7 May 2009 @ 10:52:58 pm from IP #
The system that my local client installed was a 'Dux readyhot water recirculation system', though he couldn't remember the unit cost.
He reports that it works very well, and just tells guests to 'push the button about a minute before you're ready for your shower.'
The info on the website http://www.dux.com.au/recirculation.htm
is identical to Sunshine's link, but with a different logo on the actual unit.
I don't know if either are the manufacturer, or if they are both rebadging another supplier's equipment.Posted Friday 8 May 2009 @ 1:00:56 am from IP #
Page 79 of the current issue of Renew has a Hey Presto instant hot water unit for sinks which I have been considering for our house as the sink is about 15 meters by pipe to the tap. About $249 on ebay.
Also consider a small instantaneous gas such as this for a caravan. Might be suitable.Posted Friday 8 May 2009 @ 8:16:30 am from IP #
Instant hot water is a good option for occasionally used remote locations, but the p79 ad should have the IF underlined. IF you use 100% Greenpower........
The NSW Basix system penalises 'Electric Instantaneous' hot water systems nearly as much as it does 'Electric Storage', because owners have the ability to opt out of Greenpower at any time.
In NSW an Electric Instantaneous unit like that proposed would be VERY hard to include and still pass the Basix 'Energy' module.Posted Friday 8 May 2009 @ 9:22:13 am from IP #
,The basix system seems to be fo9r new homes not existing ones. Notwithstanding that, the water saving from having instant hot water at the point of use would be compliant with the aims of basix. And you can turn it off at the wall if you are not using it.Posted Friday 8 May 2009 @ 10:08:10 am from IP #
An article has been written about hot water circulators as they were being considered for inclusion in the WELS scheme - http://www.waterrating.gov.au/publications/hot-water-circulators.html. The appendix contains a list of the circulators available in Australia and their suppliers.
I've purchased one I saw on the New Inventors a few years ago - an Enviro Save Water System. It works by pressure differential so does not include a pump. The other benefit for us (as we're on tank water only) is the expansion tank - it should stop the pump turning on and off everytime we use water. It's not installed yet as the plumber was a bit confused, so I've drawn up how I want it to be installed and am waiting from him to come back. The instructions are a little non-specific!Posted Sunday 24 May 2009 @ 10:55:28 am from IP #
The prob with hot water circulators is that they effectively extend the hot water tank into all of the pipes that the circulation system runs in. If those pipes are poorly insulated (most hot water pipes are) then your heat losses are going to increase considerably. They may save water, but they increase your water heating bills. I have seen one or two suppliers claiming that they reduce bills, but common sense would say otherwise...Posted Friday 29 May 2009 @ 1:34:57 am from IP #
The wasteful 'hot water circulators' are the systems used in hotels where guests assume that hot water will be available on demand. Certainly constant circulation of hot water in under-insulated pipes must be be an energy disaster.
The systems like the Dux Readyhot or ecosmart Water Guardian are designed to not waste the cold water lying in a long pipe run to a distant outlet. According to my client it only operates for about a minute before a shower is used. The energy losses (excluding the pump) are exactly the same as if the cooled water in the pipe was going down the drain.
They are two totally different systems used for different reasons, and aren't interchangable.Posted Friday 29 May 2009 @ 4:28:58 am from IP #
Yes, true, the on demand systems are definitely the way to go. Both of those are manual systems where you press a button to start the circulation. I also recall a system (can't remember the brand) which automatically activates each time you go into the bathroom, not such a good idea that one...Posted Tuesday 9 Jun 2009 @ 5:47:20 am from IP #
I am not aware about Cold water recirculation, but i thought you must be talking about Hot Water Recirculation Systems, hot water recirculation systems deliver hot water to fixtures quickly without waiting for the water to get hot. Rather than relying on low water pressure common in most water lines, recirculating systems use a pump to rapidly move water from a water heater to the fixtures.
In this system, a recirculating pump rapidly pulls hot water from a water heater while simultaneously sending cooled-off water from the hot water lines back to the water heater to be reheated. In addition to having the convenience of hot water on-demand, the system conserves water and can save energy.
Keep Sharing & Reading!Posted Wednesday 14 Oct 2009 @ 6:47:46 pm from IP #
What we do is so low tech, I'm almost afraid to mention it....
We run the first lot of cold water into our bath, when we get a fair amount in the bath we syphon it off to the garden.Posted Thursday 3 Dec 2009 @ 12:28:06 pm from IP #
And ours goes into a bucket, which goes on to the strawberries!Posted Thursday 3 Dec 2009 @ 3:32:26 pm from IP #
Ah you guys beat me with the bucket idea - much cheaper than a $1000 water re-circulator (-; Cold water isn't wasted by putting it on the garden. Then again I suppose if you're on tanks and want to put that cold water back in to the system for later use, the re-circulator would be needed.Posted Friday 4 Dec 2009 @ 4:06:57 am from IP #
As a Home sustainability assessor, I have seen the energy / home situation many times over the past 6 months.
I have witnessed 2 houses with these Hot water recirculating pumps, and they both had ENORMOUS energy bills- ie 80 and 90 KWH per day for each household .
To clarify- one house was on off peak HW, and that component of the bill was 40 KWh per day! (the other on smart metering)
The other place that had one had an 800 litre capacity hot water (2 x 400 ltr) and I could access the first 8 metres of hot water pipe coming from the tanks. The entire thing was too hot to hold! In both cases, the energy was being wasted to space in vast quantities.
I imagine a much better system is to use small dimension hot water lines- ie 16 mm so small volumes of hot water are wasted, and thick insulation over the entire system would be a better solution. - and get rid of the pump.
Experience shows, many plumbers have little regard for customers energy bills, or any concept of energy conservation principles, so there is little or no insulation on any of the hot water systems mentioned, or most others I have seen.
Any other similar experiences? would be interesting to hear about them....Posted Tuesday 12 Jan 2010 @ 7:23:18 am from IP #
John B, What are your thoughts on a solar pre-heat system for a hotel which is on a ring main with gas boilers? I am guessing the ring main is continuously pumped but not sure. They want to keep the gas boilers and just preheat with solar for a minimum 50% solar contibution. Not sure how this will work with the ring main/gas boiler arrangmnent or if this is the best way to go to provide the greatest environmental benefit at lowest cost. Any suggestions?Posted Wednesday 13 Jan 2010 @ 11:40:46 pm from IP #
Has anyone tried out the Ecoverta device?
Recirculates cold water when tap turned on but doesn't use power - just runs on water pressure in lines (not sure how this would work with tank and/or esp gravity fed water from tanks - guessing that one is an open-ended question) I'd be interested to hear if anyone has working experience with this litte device tho.Posted Saturday 13 Feb 2010 @ 7:54:22 am from IP #
Ecoverta essentially works on similar principles to the Redwater Diverter. A lot more expensive than the Redwater unit - maybe three times the price. I think they are now trying to copy the Redwater Valve. The Redwater Valve will work on gravity fed supply - but will not discharge to the same supply tank. Quite often water will be collected from a roof then pumped up the hill to gravity fed supply. In this instance the water diverted from this valve must go to the collection tank under the house. I am pretty sure that's how they did it in this video. You will notice that there is a lot less embodied energy in the Redwater product just by the small size of the thing. http://www.youtube.com/watch?v=CJfoRkHN-QQPosted Thursday 18 Feb 2010 @ 1:59:31 am from IP #
I have been looking into these too. If they work on water pressure in the lines, there would be many places to send the saved water. The Ecoverta is very expensive compared with the Redwater and it is larger. These are a much better way to save the water than pumps. Does anyone know what their like to install?Posted Thursday 18 Feb 2010 @ 9:34:14 am from IP #
The product you have Spammed has nothing to do with this thread. As per the Spammed website and for the benefit of forum visitors and yourself, I alert you to the following:
The volume of a '90' mm PVC pipe is less than the 6.5 litres stated due to the pipes being measured as an outside diameter. Are you aware of this?
A 'fine filter' restricts the flow path of water. If a product fitted into a downpipe reduces the downpipe's regulatory discharge rate and is not designed with an unrestricted overflow back to stormwater, the excess water during a storm event or blockage will discharge next the house. As such, products fitted into downpipes that reduce the regulatory plumbing discharge rate of water flowing to stormwater for a regions 1 in 20 year Average Recurrence Interval are (argueably) NOT COMPLIANT with plumbing regulations AS/NZS 3500. Are you aware of this?
Are you aware that the product's upper 8 mm mesh is not mosquito proof?
If the flush chamber blocks, can mosquitoes access the dirty flush?
Do you or forum visitors have any questions or require further facts?Posted Tuesday 28 Dec 2010 @ 2:07:31 am from IP #
Hi, new on here but may I suggest running your cold hot water into a bucket until the hot comes, pour the bucket into the washing machine and when you have enough in the machine do the washing. If your washing machine is unable to do this find one that does, pretty simple really and a bit more eco friendly than another pump and plumbing and associated crap.Even the kids manage it here.Posted Sunday 2 Jan 2011 @ 11:04:35 am from IP #
Hi; just registered. I will be building a house in a few months and want to install cold water diverters. Have used the bucket route for the last few years. Does anybody have any comments re comparison between the following 3 units:
- Redwater Diverter
- Enviro Save
- Ecoverta TSV
Thanks in advance for any advice.Posted Thursday 5 May 2011 @ 5:13:33 am from IP #
I've also been researching cold water diverters for our new sustainable build and have seen your message from last year. I was hoping you have installed a system and can give some feedback on which product you went for and how it is working out.
CheersPosted Tuesday 28 Feb 2012 @ 3:00:42 am from IP #
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