In reply to message posted by Jerry Peck:
The purposes of a pump driven or gravity flow hot water recirculating system are two-fold:
1) to provide almost instant hot water at each tap off the recirculating loop
2) to also save water
By providing almost instant hot water at each tap off the loop, there is no need to run a lot of water to get hot water, thus, the non-wasted water (to get hot water to the faucet being used) is saved.
I think you may be confusing saving water and saving energy. A hot water recirculating system save water, however, it may (or may not) save energy.
If installed in a frequently used system, the hot water recirculating loop may also save energy.
If installed in a seldom used system, the energy spent continuously pumping the water (not applicable to gravity flow systems) may offset the energy to heat the water being wasted in a non-recirculating system (turn the hot water on, let if flow down the drain until the water finally gets warm enough – forget getting hot, just warm enough).
I’ve always thought is a lack of thought when the plumbing code REQUIRES 1.6 gpf commodes, yet ALLOWS wasting gallons of water just to get hot water to wash your hands after using the WATER SAVER commode. Aren’t you supposed to wash your hands with hot water after using the bathroom?
I inspected a house last week with a separate guest house where, after running the ‘hot’ water at the bathroom lavatory faucet for 15 MINUTES, the water was only just getting to 90 degrees (measured with a thermometer, not guessing). No, no one invloved with designing or building the house thought about installing a water heater in the guest house.
Hi Jerry here is an article I wrote in July 1999 http://www.masterplumbers.com/plumbviews/1999/rec_pump.html
This is one of my favourite questions:
Is a hot water recirculating pump an energy/water efficient purchase or a luxury purchase?
We’ve heard that it pays for itself in 3 years.
How can that be when you’re paying for a pump to be running and when there’s heat loss from pipes through which hot water is constantly being recirculated?
Here’s my response to this great question, but to make it more interesting we will let you be the one to answer it.
Let me just give you some facts ok.
When you turn on the hot water faucet (tap) you normally let the water run and run and run until it gets hot correct so far? Y or N
This wasted down the drain water was heated and now when the water is shut off the hot water remaining in the pipes will again cool off Y or N ?
If your paying for water Via a water meter your not only wasting fuel BUT precious potable water correct Y or N ?
If you had a recirulation pump you would not put undo stress on your H/W heater due to thermo shock of cold water entering this tank as the cold water would be TEMPERED with the hot return water correct Y or N ?
The actual circulator would be of minimal horse power like 1/12 or 1/16 just enough to keep the water moving. Y or N ?
With this added on ENERGY saving device would you not also be getting an added benefit of almost instant H/W with little loss of water. Y or N ?
All water heaters have stand by losses and if you stayed by your heater you would hear it come on and off several times during the day. Y or N ?
Now lets consider all the above if you had a constant circulation with insulated pipes your actually saving your heater from trying to heat cold water from entering the system you would have much less condensation less thermo stress on the tank, MUCH, MUCH less waste of clean fresh water. Not paying for water to sit in a pipe cool only to be run down a drain waiting for it to get hot again to start this wasteful cycle again.
As more and more localities meter the water and prices start to sky rocket as clean fresh water isfind and as more water is wasted and larger pipes are needed to convey water to your home and other people who waste water and your Gas/Electric bills climb higher to make up for people literly throwing HOT paid for water down the drain. Then you can tell me if it is cheaper to install an INEXPENSIVE efficient bronze circulator or not?
I would never be the one to give a snap judgement saying yes they don’t pay for themselves as we have to make our own minds up. You decide if this is just a “convience” or the right energy water saving thing to do.
Imagine this July 23 1999 and here is is 2002 and my advice is still sound Talk about being a head of my time LOL By the way I have installed REC lines from the day I started plumbing way back when there were mechanics who cared