4300 Gallon Plywood Build (3600+ Take 2)

[NOLAGT]

wow...they have such a cool job

 

[Sirspifalot]

I like the closed loop THWH. For a possible solution to the superheating water problem, perhaps you could purchase a THWH that has a low output/capacity. As you said before with that gallonage and you being from a relatively warm climate it shouldn't take too much effort on the heater's end to maintain the tank temperature. So in theory it would take a longer period of time to heat the water and thus would take a substantially long period of time to superheat the water in the event of a thermostat failure and then would give you time to catch it and rectify the problem. Just thought I would add an idear. Or I might just be making stuff up....I don't know much about THWH but it makes sense in my head..... Or second idea is to hire a dragon. Then you could call him Pete's Dragon. And he would be invisible so the roommate wouldn't even notice.

 

[johns]

I now You are against electric heaters, We use a lot of these at work, reliable and activated by flow. Another option.
http://www.chronomite.com/

 

[nolapete]

I like the closed loop THWH. For a possible solution to the superheating water problem, perhaps you could purchase a THWH that has a low output/capacity. As you said before with that gallonage and you being from a relatively warm climate it shouldn't take too much effort on the heater's end to maintain the tank temperature. So in theory it would take a longer period of time to heat the water and thus would take a substantially long period of time to superheat the water in the event of a thermostat failure and then would give you time to catch it and rectify the problem. Just thought I would add an idear. Or I might just be making stuff up....I don't know much about THWH but it makes sense in my head..... Or second idea is to hire a dragon. Then you could call him Pete's Dragon. And he would be invisible so the roommate wouldn't even notice.

LOL on the dragon.

Here's the new diagram. It uses my household natural gas hot water heater to heat it, putting a Y on the supply to my washing machine, and returns to the drain the washing machine uses.


grey square is thermostat and normally open solenoid valve
these are connected to the red pex line
the red pex line connects to household hot water supply

purple square is thermostat and normally closed solenoid valve
these are connected to the end of blue pex line
the blue pex line connects to the drain that washing machine uses

when probe to thermostat 1 determines heat is needed in tank (probe placement to be decided later)

1st thermostat powers up second thermostat (and possibly circulation pump)

second thermostat checks temp of water at end of pex run

the water temp would be cool at this point (less than 100 degrees I'm guessing)

second thermostat opens 2nd solenoid to allow water flow from house hot water supply when pex temp is above base temp valve closes

when thermostat 1 detects tank temp is correct it powers down second thermostat and solenoid which will stay closed because it's normal position is closed

the second solenoid is normally closed, so it prevents catastrophe should there be a power failure

I'll be installing a whole house natural gas generator in the not too distant future.

 

[nolapete]

I now You are against electric heaters, We use a lot of these at work, reliable and activated by flow. Another option.
http://www.chronomite.com/

If I end up needing to add the tankless hot water heater, I'll consider it. The THWH I had considered using before is electric. I'm not so much against electric hot water heaters. I'm against using standard heating elements and aquarium/pond/pool/spa type electric heaters. It's not that they don't work, it's that they are so expensive to run.

 

[Muni]

Looks like a solid idea but would require some testing to be sure.

How is it you steal all the thunder? 17 people viewing this thread and only 1 on mine.......


Guess people are fascinated by your big huge..... TANK.

 

[johns]

In Your climate, and in Your House I am thinking it really will not take a hole lot to maintain temperature once it is heated. I have to wonder if You may be over engineering it. I believe You have said Yourself wood is a good insulator.
Just a thought.
Cant wait to see how You end up doing it.
Must say truly inspirational build. One day I would like to do the same.
Look forward to Your updates!

 

[Muni]

In a heated house you may not need much more then an 800W titanium heater. That much water would take a while to cool to room temperature which will be what? 5 degrees different?

Dunno. I'm confused now. The pretty color drawing threw me off.

 

[Open Water Predator]

This seems unnecessarily complicated. First rule of engineering: the simplest solution is the best solution.

 

[nolapete]

Hehe, OWP!!!

it's really very simple

main thermostat tells heat to come on like every other heater, but instead of having an electric coil it has a pex coil that fills with hot water. the second thermostat and valve tells it that the coil needs to be heated again and opens to let more hot water come in and reheat the coil.


-==-

And with that explanation I figured out how to do it with just one solenoid valve; the second one

first thermostat monitors tank temp then powers up second thermostat when it needs heat

second thermostat checks pex water temp then opens valve if temp isn't hot enough to allow hot water in from the supply.

yay, simplified!

now, if I can find one inexpensive thermostat that can monitor two probes and respond, I can simplify even more...