Author Topic: Schedule Hot Water Recirculation Pump?  (Read 7970 times)

Offline tvipond

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Re: Schedule Hot Water Recirculation Pump?
« Reply #15 on: April 22, 2013, 01:11:23 pm »
To Add to the already great conversation...I did this exact thing in my house...not a vacation house, but I stepped it up a little.

Instead of simply turning the circ pump on and off, I added a thermocouple on the circ loop piping as well. I actually turn on and off the hot water tank on predefined schedules or if the "On Holidays" virtual switch is triggered. This saves energy not having to maintain the water temp when not needed. I feed my tank with pre-heated hot water from a Geothermal so if my tank was ice cold when the tank electricity comes back on, it only takes about 1/2 hour to get to usuable temp. I just ensure that I enable restore the "On Holidays" switch via my cell phone when I am at the airport waiting for my flight home. For the recirc pump, place a thermocouple on the piping so you can actually get a variable speed pump or better yet, just turn the pump on and off if the temp in the circ loop is sufficient. I think the waste of energy from running the pump pales in comparison to the waste of energy because of heat loss in the water that is in the loop. Most loops are not insulated so therefore, you are heating the house with the loop, which causes your hot water tank to be running excessively. It is not the most efficient for heating your house. Let your high efficiency furnace do that and not your hot water tank.

Just my 2 cents.

Offline RichardTSchaefer

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Re: Schedule Hot Water Recirculation Pump?
« Reply #16 on: April 22, 2013, 04:51:42 pm »
I have instant Hot Water ... not as efficient ... but since I do not use it often ... I do not waste energy trying to keep water warm in a storage tank.

Actually I do have a storage tank (Small 20 Gal How Water tank that is NOT turned on) as the input to the Instant On Hot Water. If I do circulate water ... the excess hot water pre-heats the water in this tank. If the stored water gets too cold ... then I circulate the water just to preheat the water in the 20 Gal tank. If I did not want the option to pre-heat the water ... then the thermostat would be the better option.

My heat loss in the lines is pretty low ... since all of my hot water lines ... including the return line ... are insulated.

For me the power is cheap ... the waste of water is a big problem.  We have been in a severe drought. I do mot want to waste water and let the water go down the drain while people wait for hot water.


Offline tvipond

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Re: Schedule Hot Water Recirculation Pump?
« Reply #17 on: April 23, 2013, 01:38:19 am »
I think it is brilliant to only circ the pump when lights or motion is triggered. I did try a primitive trial of that when I started but with the size of my house, the number of bathrooms and the distance of pipe between the main bathroom or kitchen and the hot water tank, it takes over a minute for the hot water to reach. The wife nagged me to submission and i added the thermocouple instead to at least turn off the pump Intermittantly. Your concept of only turning it on when needed is the best but for me I would need to investigate a small secondary tank to hold and reheat water. It might definitely pay off for me though.

Cheers.

Offline Pseudomizer

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Re: Schedule Hot Water Recirculation Pump?
« Reply #18 on: December 18, 2015, 03:09:44 pm »
However running the recirc pump cost about $90/mo in electricity charges there. 

Seriously? I got one installed at my home where we live (not a vacation home) and my bill didn't go up that much. I will try to figure out how much that thing consumes but that high of a number seems unrealistic.
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