Water Heaters: Tankless vs Traditional

[riverview]

I wondered about this because basically your circulating hot water, so you have it instantly.

 

[Maddog]

I know a recirc pump is costly, but one time cost.

Add to loop, turn on prior to wanting hot water at faucet. It shuts off with thermostat (another cost).

Then have hot water at the faucet.

For us it would be in the kitchen.
We easily know beforehand when we will want hot water there.

We haven't done this yet as I was hoping that @guywhodoesthehomeworkforusall would come back with some data on his gravity loop install. Thanks for keeping us in the loop [MENTION=337]guywhofishes[/MENTION] Puns unlimited, LLC

 

[riverview]

oh yea and what are you a rocket scientist to make graphs?

 

[Maddog]

I wondered about this because basically your circulating hot water, so you have it instantly.

"I want it. And I want it NOW" :;:muahaha

 

[guywhofishes]

Guywholikestoshare did you compensate for price increase of said kwh from year to year, you probably did that and I'm an idiot for stating the obvious.

I just compared the two Jan bills for water heater meter $$. So no.

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oh yea and what are you a rocket scientist to make graphs?

Cass County Electric has a kicka$$ billing/usage interface. Just snipped a bit of the screen.

They probably developed it with fed money - in preparation for monitoring every KWH, fining heavy users with "unnecessary and wasteful gravity loops", etc.

 

[MathewsZman]

 

[johnr]

So - here's the effect of my gravity loop. The green usage is "normal" electricity meter - and the orange is the off-peak meter that measures only my water heater (in the winter anyway).



Guess what day I turned the valve on for my gravity loop?

Turns out that 3/4" return line is maybe overkill - Ima close the valve part way and see if that doesn't calm things down. ;:;rofl

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January 2021 we used 7 KWH/day on water heater. = $21.12

January 2022 we used 14 KWH/day on water heater. = $33.40

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looks like my gravity circulator uses more hot water to heat the house than we use each day to shower, wash cloths, etc. ;:;rofl

In the winter... meh, I don't care (it's heat). But in summer I'll be heating the house and then cooling it with AC. That'd be dumb.

So I'll either valve things down OR install a smart scheduled valve (shut it down most of the day and open it for typical shower and hot water usage hours).

So me running the kitchen or master bathroom sink for 1 1/2 minutes to finally get some hot water is still a way cheaper (albeit frustrating) way to go

 

[tikkalover]

The gas pump says the same thing on it when I put gas in the cars.

 

[lunkerslayer]

I just compared the two Jan bills for water heater meter $$. So no.


Oh OK I just figured with everything else that has gone up in price electricity would also, so you are using more hot water by means of loss of heat through your pipes I presume. Since hotwater is being circulated constantly through pipes the water is losing just a little bit of its heat hence higher bill?

 

[guywhofishes]

don’t think electricity rates have gone up much like gas has

right - even though the hot water and return line are both insulated they lose a lot of heat - so you end up heating the house with your hot water heater - which in the winter isn’t too big a deal but come summer it’d be a total waste

I partially closed the ball valve and will monitor the temp of the return line with a bbq wifi temp probe

it returns at 95-100F w valve open - probably way hotter than necessary

I’ll share any findings later

 

[sl1000794]

don’t think electricity rates have gone up much like gas has

right - even though the hot water and return line are both insulated they lose a lot of heat - so you end up heating the house with your hot water heater - which in the winter isn’t too big a deal but come summer it’d be a total waste

I partially closed the ball valve and will monitor the temp of the return line with a bbq wifi temp probe

it returns at 95-100F w valve open - probably way hotter than necessary

I’ll share any findings later

I don't believe the hot water lines lose "A LOT OF HEAT." See that I said "I BELIEVE." The re-circ pumps are fractional hp pumps - something like 1/5 hp. I run mine 24/7 when we are in our CA house. I'm retired and do not shower in the mornings when I get up - I shower when I want to be clean to go out ... ergo I want hot water when I need it at all times of the day. I have hot water wherever I want it within 5 seconds. What ever the cost is I'm willing to bear it and I cannot think it affects our household budget. For you guys back there with your low electricity rates it should not be a consideration if you can put one in!!! ACCESS, ACCESS, ACCESS!

 

[Maddog]

don’t think electricity rates have gone up much like gas has

right - even though the hot water and return line are both insulated they lose a lot of heat - so you end up heating the house with your hot water heater - which in the winter isn’t too big a deal but come summer it’d be a total waste

I partially closed the ball valve and will monitor the temp of the return line with a bbq wifi temp probe

it returns at 95-100F w valve open - probably way hotter than necessary

I’ll share any findings later

You looked at the increase in electrical cost.
Perhaps harder to determine, but bet you could do a ballpark estimate -- what is the cost savings in reduced water consumption. Assuming you are on city water. ?

 

[guywhofishes]

OK, so here's a graph of what happened with the gravity loop.



I was using about 5 kwh/day for the hot water heater. After installing the gravity loop (Dec 16 or so) you can see the energy use jumped to nearly 3 times as much. I thought that was a bit much - how to achieve a happy medium???

I bought a this $31 controller for reptile cages, etc.
https://www.amazon.com/gp/product/B01486LZ50/?tag=nodakangler10-20
On March 21 or so I placed the temp sensor of the Inkbird on the return gravity loop near the heater. I hooked the Inkbird controller up to one of those zone valve controllers for boilers that I installed into the return ($70 ebay).

The zone valve opens until the return water gets to 90F, then it closes until it drops down to 85F, then re-opens. This is equivalent to those water circulators that monitor temperature and don't get carried away by circulating unnecessarily.

In addition, this $31 Inkbird controller allows you to set what time you want to be controlling or not (so lizards etc. experience cool nights). So I set it to start allowing the gravity loop at 5 am and end the gravity function at 8:00pm (I think those are the times... it's all programmable but forget)

Anywho... it looks like I might be saving 5 kwh/day which at .069/kwh is $10/month - by not running the loop at night when it's not needed. So the $120 bucks or so I spent on controlling the loop will be paid off in a year? I suck at math so I could have this all muffed up. Ha ha.

-guywhoisOCDsometimes

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So the final system sent my hot water usage from something around $17/month to maybe $27 or so. I can live with that - especially in winter when heat is heat - it doesn't get wasted. Summer is a different animal.

 

[johnr]

I am still just running the sink for 1.5 minutes each morning, and the same afternoons in the kitchen to get hot water.
I am guessing my water waste is costing less than what guy is going through

 

[guywhofishes]

I am still just running the sink for 1.5 minutes each morning, and the same afternoons in the kitchen to get hot water.
I am guessing my water waste is costing less than what guy is going through

Ha ha - Without a doubt.

You're definitely greener.

 

[riverview]

my house at dvl the water heater is directly below 2 bathrooms and kitchen, ran 3/4 inch lines to the bathrooms hot water is pretty instant, the other bathroom 40 feet away im thinking of installing a tankless just for that bathroom.

 

[lunkerslayer]

Guywhofishes you are on to something with this idea, we can see you have put a lot of thought into this. Tankless heaters have thier draw backs number one is reliability or longevity compared to a traditional water heater.
Juanr is correct by just a little bit becuase the system isn't built yet where we are charged for exactly how much water we are used each month. Every place that I have rented where I pay my own water bill I was alloted a 1000 gallons of water in that 30 day cycle regardless if I only used a hundred gallons I still had to pay for the whole 1000. In a way that is how our government runs for everything, people who budget for a fiscal years cost proposes so much money for a year and if they don't use all that money they get less for the next fiscal years budget. Another system built on waste of natural resources of water is farmers in Arizona who use metered water for irrigation purposes, regardless of how much water they use even if they are getting natural rainfall they have to use what water is alloted or the can actually be penalized by having less water for the next years crops. There are so many more examples of resources and money wasted for the fear of not knowing what the future brings.
So back to guyswhoshares idea, this idea is a great idea for future homeowners who are looking to build and use a traditional water heater. You could set up a whole system for this design it from the beginning with hot water lines that are insulated though out the house cutting back heat loss. It could be set up using a wifi system where it's regulated though a computer system that controls all the areas of the house.
Well done right now yes juanr and the rest of us are considered greener but if our utilities are ever run more efficiently with a on demand approach you would win by mile.
Anyone remember the infrastructure bill Biden administration proposed? Well one of those was data infrastructure where more high speed data lines of cable will be put in for that very reason besides internet access but also to connect everyone so utilities can be read automatically saving money i guess.
Great ideas guywhofishes you have always like to share with us your ideas and I am one of those who appreciate it.

 

[wslayer]

I am still just running the sink for 1.5 minutes each morning, and the same afternoons in the kitchen to get hot water.
I am guessing my water waste is costing less than what guy is going through

Have that same issue, takes forever to get hot water. My basement is partially unfinished and only part of it heated. I bought some foam pipe insulation that did helps little bit. The part that is finished, the drop ceiling ( only about 1" below floor joists ) makes it a pain in the ass to do those lines.

 

[Davey Crockett]

My camper has one of those under the sink heaters water is always instantly hot when it's turned on . We have well water for the house so it's not a big issue for us to wait.

 

[guywhofishes]

Have that same issue, takes forever to get hot water. My basement is partially unfinished and only part of it heated. I bought some foam pipe insulation that did helps little bit. The part that is finished, the drop ceiling ( only about 1" below floor joists ) makes it a pain in the ass to do those lines.

Same - when I redid the ceiling I bought a hogass big drill at Harbor Freight and bored holes large enough for both the PEX and the foam insulation (which is so thin it's likely a waste) -

paying careful attention to the rules of drilling holes in joists of course

pretty sure it didn't do much damage and walking in the living room is easier on the knees now. The floor gives nicely, sort of like a WWE rassling ring.

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for sale: one slightly used honking big drill and some big bits