Hot Water Recirculation Systems. Please proof this new inspection article.

[Nick Gromicko]

http://www.nachi.org/hot-water-recir...on-systems.htm

[Bruce A. King]

The picture has the wrong title, it should say "dedicated loop".

The text under the "integrated loop" section mentions a pump installed at the far fixture, actually the pump is more likely to be found at the tank and a crossover valve installed under the far sink.

Where it says 1.3 trillion gallons, it indicates per house, it should indicate a total of all households added together.

Under Inspection Considerations, on systems that use a check valves, a thermal expansion device must be present.

[Joe Funderburk, CMI]

It says "copper piping" is required (under the cost section). PEX is the predominant plumbing system today.

The illustration doesn't do anything for me. Not enough detail.

[Rob London]

Originally Posted by bking

The picture has the wrong title, it should say "dedicated loop".

True.

Originally Posted by bking

The text under the "integrated loop" section mentions a pump installed at the far fixture, actually the pump is more likely to be found at the tank and a crossover valve installed under the far sink.

Read the article closer. One of the defining elements of the integrated loop system is that there's a pump at the far fixture.

Originally Posted by bking

Where it says 1.3 trillion gallons, it indicates per house, it should indicate a total of all households added together.

Nice catch

Originally Posted by bking

Under Inspection Considerations, on systems that use a check valves, a thermal expansion device must be present.

Please explain why this is the case, or provide me with a source.

[Rob London]

Originally Posted by jfunderburk

It says "copper piping" is required (under the cost section). PEX is the predominant plumbing system today.

Good point

Originally Posted by jfunderburk

The illustration doesn't do anything for me. Not enough detail.

What can we do to it to make you happy?

[Bruce A. King]

Rob,

I think all water heater manuals state that a thermal expansion device is needed if you have a closed loop setup. I read it in one years ago when I realized my plumber forgot to install mine and the code guy missed it.

[Marcel Gratton]

I am concerned with the *integrated loop system* where hot water is re-circulated intermittently and is returned to the water heater via the cold water pipes. The article states that this raises the temperature of the cold water slightly, but it returns to the usual cold temperature in a short time.

My concern would be Legionella bacteria which multiply in ideal temperatures; such bacteria can result in a form of pneumonia which can cause death.

My thoughts is that cold should be kept cold and hot should be kept hot, anything in between is asking for trouble...

I would not recommend this type of system to homeowner having private water supply (well).

Food for thoughts!

[Roy D. Cooke, Sr]

Originally Posted by gromicko

http://www.nachi.org/hot-water-recir...on-systems.htm

http://www.watts.com/pdf/PF-IHWRS.pdf

Tank water temp is 160 tap water temp is 108

I have had one for two years and love it .
Roy

[Bob Elliott]

I like the graphic.
Would maybe add another without the return to show the difference.

[Marcel Gratton]

Originally Posted by rcooke

http://www.watts.com/pdf/PF-IHWRS.pdf

Tank water temp is 160 tap water temp is 108

I have had one for two years and love it .
Roy

Roy,

You must have a tempering valve installed at the WH; 160 degrees is excessive and will prematurely wear out the tank in my opinion.

How much water is wasted for that glass of cold water but more importantly, how much energy is lost inside walls by hot water being circulated when not needed...

Me think it is more of a convenience than being green.

Just my thought.