It looks so cozy! 🤗
Would've been pretty cool to get before-and-after energy numbers... 😁
Would've been pretty cool to get before-and-after energy numbers... 😁
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Boy I'm glad you asked about the energy usage, it forced me to chase down an issue I had noticed but didn't understand. I don't leave the water heater on all the time I just turn it on when I want hot water. But, the hot water seemed to cool off really fast, compared to when I had tested it with the water tank unconnected to the distribution piping. Preliminary electrical test results showed that I'm using at least twice as much energy as you (I can't show the graph as the Victron portal is down.) Here's a one-line diagram of my plumbing system, note the hot water re-circulation loop. This is so you don' t have to run the faucet and waste water to get to hot water:
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I think that created a convection loop that pumps heat out the tank since the interconnect valve between the hot and cold water is open when the hot side is cold. The cold water piping coming out of the water heater was hot, which was my first clue what might be happening. When I closed the cold water valve to the water heater the piping cooled off and the time between reheats doubled. I've got a back flow valve coming from Amazon that I'll put in the hot water piping, I think that will break the loop. I'm also going to insulate the cold water piping. Then I'll test it again.
Bruce
P.S. The water cooling off too fast was what spurred the cozy.
I think that created a convection loop that pumps heat out the tank since the interconnect valve between the hot and cold water is open when the hot side is cold. The cold water piping coming out of the water heater was hot, which was my first clue what might be happening. When I closed the cold water valve to the water heater the piping cooled off and the time between reheats doubled. I've got a back flow valve coming from Amazon that I'll put in the hot water piping, I think that will break the loop. I'm also going to insulate the cold water piping. Then I'll test it again.
Bruce
P.S. The water cooling off too fast was what spurred the cozy.
I used velcro cable ties to attach a Ruuvi tag to the pressure relief valve and then covered it with another thinsulate cozy. Then you can use your Cerbo to keep track of the water temperature.
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It's close enough for me.
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Bruce
It's close enough for me.
Bruce
Victron portal is up, here's a graph of electrical usage from 11am 5/21 to 6pm 5/22. Wow, shutting off the re-circulation loop had a dramatic effect. The heat was coming on every two hours. Once I turned the shutoff valve to the water tank it didn't call for heat for eight hours.
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More to follow...
Bruce
More to follow...
Bruce
Okay here's my final answer;
gregoryx 24 hour results:
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My 24 hour usage with the cold water valve closed:
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It looks like the cozy saved around 20% on energy use since the heater turned on four times instead of five.
Here's the 48 hour usage, the blue mark is where I closed the cold water valve to the water heater:
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Plumbing, I've never liked plumbing.
Bruce
gregoryx 24 hour results:
My 24 hour usage with the cold water valve closed:
It looks like the cozy saved around 20% on energy use since the heater turned on four times instead of five.
Here's the 48 hour usage, the blue mark is where I closed the cold water valve to the water heater:
Plumbing, I've never liked plumbing.
Bruce
Excellent idea! I suspect if I use a hard-wired probe with a metal sensor it should be a bit closer / hotter. Oooo... and I think I may be able to do an "offset" for the temp to get it closer to internal. Great idea!
What temp / dial-position do you have the Bosch set to? We run as hot as possible on ours.
That is pretty cool - probably a pretty close estimate of the improved efficiency of the cozy - assuming you're running hot-as-possible as well.Okay here's my final answer;
...
It looks like the cozy saved around 20% on energy use since the heater turned on four times instead of five.
Here's the 48 hour usage, the blue mark is where I closed the cold water valve to the water heater:
...
Plumbing, I've never liked plumbing.
...
And almost extra funny that it was the recirc that was really the issue. But you now have the coziest water heater around! 😁
Funny thing is... I sort-a like the plumbing in the van - where I can easily access things and readily repair them. In the house, though... tearing apart walls and floors? Ugh. Hate that. 😏
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