Where to start looking for Energy Savings

[jebatty]

Everyone's needs can be different. For my wife and I, and 90 gallons of hwh (2 electric WH's), super insulated, all hot water lines insulated, and effective heat traps on the hot and cold water lines, average monthly electricity use is 100 kwh, we have never run out of hot water (well once, when a grandchild left the hot water faucet on), and since the HWH is on an interrupt rate, cost of electricity is about $0.05/kwh, or $5/month.

I am a proponent of an inexpensive standard electric HWH, but also installed with much added insulation, all hot water lines insulated, and effective heat traps on the hot and cold water lines ... plus hot water conservation habits.

 

[sloeffle]

No need to get too complicated with the HPWHs. I'd nix the preheat idea. If you look up the COP versus tank temp data, the COP is super high (4+) when the water is cold. Most of the energy goes to 'finishing' the hot water...the last 20°F or so the COP plummets.

Bottom line, a geo preheater is unilikely to save you a dime (if I understand your idea).

If the Marathon wasn't already bought and paid for and I didn't have the geo then I would agree with you.

I can hook the Marathon up to my geo in about an hours time and 20$ worth of pex and fittings. The geo basically ( cost to run the pump ) makes free hot water in the summer. I am not sure why you wouldn't want to use that ? The only downside that I see is that the HPHW would not run as much in the summer and you would loose some of the humidification benefits. If this does end up happening I can simply flip the switch on the front of geo to turn the DSH off.

I am a proponent of an inexpensive standard electric HWH, but also installed with much added insulation, all hot water lines insulated, and effective heat traps on the hot and cold water lines ... plus hot water conservation habits.

Any experience with the in line heat traps ? It looks like they have a small flap in them.

 

[maple1]

I was wondering about the inline traps too & how effective the one was that came installed on the top of my heater. I couldn't really feel with my hands that heat was creeping up the pipe, but I was also having a hard time remembering to do it after a really long period of no hot water use. I ended up soldering one into the hot out pipe anyway.

 

[sloeffle]

Update:

In April of 2015 I bought a AO Smith 50 gallon HPHW. I was going to purchase one in March but the place I bought it from could not procure any 50 gallon units for about 45 days. I got the unit installed in May and have been reaping the savings ever since. We no longer have to run a dehumidifier in our basement so that has also added onto the savings. At my current savings rate the ROI on the HPHW is 16 months.

Our June 2015 usage could be even lower, but we ended up getting more baby chickens. They require a 175 watt heat lamp 24 x 7 for at least 4 weeks. The total utilities ( electric, city water ) for our 2200sq ft house last month were 120$. No complaints here.





Thanks again,

Scott

 

[DaveH]

Update:

Are you going to pre heat the water in the AO Smith? How is the noise?









Thanks again,

Scott

 

[sloeffle]

Water is preheated by the geo ( when it is running ) and finished off by the HPHW.

Unfortunately the HPHW is below our bedroom. It isn't very noisy, but you can tell it is running. I will probably insulate the bottom of the floor one of these days to cut down on the noise. If I had a full basement and a blank slate, I would move it underneath the kitchen or laundry room.