Insulate Your Water Heater

[ErrolFlynn]

You are looking for a circulating system design, not recirculating design.
Check out the link for designs or to do your own search, look for hot water circulating design.

hot water circulating design - Search

Thank you for that. I had no idea such systems existed. My initial reaction was - what a brilliant idea. Though, I wonder about the pump running continually. All very well to be thinking of saving water, but the system is doing that at the cost of extra electricity usage. With power prices rising seemingly all the time do we really want to spend extra cash on the convenience of instant hot water?

Though, if there are a few solar panels on the roof and a battery the can take you through the night this seems like a lovely system. Much obliged to you.

[rambunctious]

Thank you for that. I had no idea such systems existed. My initial reaction was - what a brilliant idea. Though, I wonder about the pump running continually. All very well to be thinking of saving water, but the system is doing that at the cost of extra electricity usage. With power prices rising seemingly all the time do we really want to spend extra cash on the convenience of instant hot water?

Though, if there are a few solar panels on the roof and a battery the can take you through the night this seems like a lovely system. Much obliged to you.

We are not talking about a pump like a pressure pump on a tank supply, it is simply a small pump circulating the water.
I have no idea of the power draw but I would imagine it would be minimal.
As I said above, it can be also set on a timer for use only when required, or, it could be wired to a switch with a pilot light in each room and switched on and off as hot water requirements dictate.
eg. walk into a bathroom, switch on pump, undress, and hot water almost instantly available.
The pilot light would remind the user to switch off when leaving the room.

hot water circulating pumps residential - Search

[Warb]

I installed one on our previous house when we built it, because we were on tank water and I didn't like watching water go down the drain waiting for the hot to arrive! They are really very simple, a small circulating pump with a switch in each room - we put the switches either in the same plate as the light switch (press them when you enter the room) or in a powerpoint (kitchen bench etc.). They require some extra pipe, as you circulate water round the house from the "top" of the hot tank back to the inlet. When the circulating pump detects hot water, it "knows" the system is hot and stops pumping - it also acts as a one-way valve, so water doesn't flow to the tap from the inlet via the "return" pipe.

That bit is all easy and doesn't cost too much if installed at build time (retrofitting might be different!). However, the big issue is if the law wherever you are states you must have a tempering valve feeding showers and basins. If you do, then the system will fail because it can't mix hot and cold and then return all that water to the inlet! The solution to this is to install tempering valves in each location that requires one, so every outlet has a tempering valve, which adds to the cost at around $120 plus plumbing each. We designed ours with one per bathroom, with minimal uncirculated water (short pipes!) between the tempering valve and the hot tap and shower. Not all hot outlets require a tempering valve, from memory the laundry and perhaps kitchen are OK at hothothot temperatures, but I may be wrong - it was some time ago!

If you fit such a system, also insulate all the pipes (including the return, there's no point in wasting warmth!) to save heating costs as well as water.

Overall, on tank water I believe it was well worth the cost. It also avoided waiting for the shower to get hot - press the button on your way into the bathroom and the water is warm when you turn the tap on!

[419]

I found the one I saw on TV all those years ago; Enviro water Saver

My dodgy memory got it slightly wrong; what it does is divert the water to a tank or similar while it is waiting for the hot water to arrive at the tap. Think of it more as a drain diverter; instead of sending it down the plughole it diverts it to a storage device.

I guess it would be perfect for tanked water and really good for people with high water bills and low rainfall who have rainwater tanks fitted.

If you're off grid or just conserving water in rural or urban areas by flushing your toilet mainly for solids, it'd be a handy feeder for the cistern line.

This would be fine if you're already using potable water for that purpose, but wasteful of potable water if not.