OWB Build

[Kellyj]

I know a plumbers thing.
We need to understand, you're not using a "pump", you're using a circulator.

A pump, like a well pump, builds pressure.
A "circulator", well, circulates water. The only pressure a circulator will build up is outlet side, pushing against the "head", (friction in pipe and fittings) until it reaches the suction side of circulator. It's essentially a closed loop.

[SPD748]

I know a plumbers thing.
We need to understand, you're not using a "pump", you're using a circulator.

A pump, like a well pump, builds pressure.
A "circulator", well, circulates water. The only pressure a circulator will build up is outlet side, whpushing against the "head", (friction in pipe and fittings) until it reaches the suction side of circulator. It's essentially a closed loop.

I think I understand. You're saying that, in an open loop, water that needs to be pumped 'uphill' requires a different calculation than water that needs to be pumped 'uphill' then back within a closed loop.

-lee

[reride82]

I know a plumbers thing.
We need to understand, you're not using a "pump", you're using a circulator.

A pump, like a well pump, builds pressure.
A "circulator", well, circulates water. The only pressure a circulator will build up is outlet side, whpushing against the "head", (friction in pipe and fittings) until it reaches the suction side of circulator. It's essentially a closed loop.

I think I understand. You're saying that, in an open loop, water that needs to be pumped 'uphill' requires a different calculation than water that needs to be pumped 'uphill' then back within a closed loop.

-lee

You are correct Lee. When you have to pump one way up a hill, you need to overcome the vertical head, and 4' vertical head is minimal. But, in a closed loop such as this, it works more like a syphon and you need to overcome the restrictions within the system I.E. sharp turns, undersized piping, long distances, valves, etc.

Levi

[Kellyj]

First, I'm doing this on my phone, some spelling errors.

You're not pumping, you're circulating.
There is no "uphill" calculation.

Sizing the "head" requirements are based on pipe size, length, fittings, and equipment you are circulating through. Then we need to know your BTU load, 1 gallon @ 3-4 fps will flow 10,000 BTUH.

Lastly, though you can put OWB lower than your heating appliance, you will have less problems if it is equal to or higher. Unless of course, you are making a pressurized boiler.

[thecfarm]

 I had Taco 14 on mine OWB. I had it installed by someone that knows,but they was too big for what I needed. The guy gave it some thought and his thinking was the water was still going fast when it came back around and was making the propeller spin too fast. Dropped down to 007 and my pumps started to last more than a month or 2. He was real nice. Returned my money of 2 Taco 14 and I went and bought 2 007. Was quite a price difference too.
I have about a 25 foot run into the house and it drops down about 4 feet. Into the garage it raises about 7 feet.

[SPD748]

First, I'm doing this on my phone, some spelling errors.

You're not pumping, you're circulating.
There is no "uphill" calculation.

Sizing the "head" requirements are based on pipe size, length, fittings, and equipment you are circulating through. Then we need to know your BTU load, 1 gallon @ 3-4 fps will flow 10,000 BTUH.

Lastly, though you can put OWB lower than your heating appliance, you will have less problems if it is equal to or higher. Unless of course, you are making a pressurized boiler.

Thanks. I'll keep that in mind when building the OWB frame. I may be able to lift the unit high enough to make it level with the heat exchanger/water heater.

Keep the questions coming Better to pick brains now befor the welding starts .

I totally agree. I'd rather make mistakes in the abstract than in fabrication. Abstract is free, fabrication... not so much  ;)

-lee

[Kellyj]

I had Taco 14 on mine OWB. I had it installed by someone that knows,but they was too big for what I needed. The guy gave it some thought and his thinking was the water was still going fast when it came back around and was making the propeller spin too fast.

How can a circulator, in a closed loop make itself spin too fast?

The Taco 0014 is a different animal than a 007, for sure

[gspren]

  Lee, on your last drawing your smoke shelf/tubes are close to what I describe except on my P&M they are side by side both in the water chamber. Smoke enters in left rear and travels forward to a 180 then exits right rear straight out the back into a T, if you take the cap off the T and open the front clean out door you can see straight through. I am not saying that's better, only describing what I have, you seem to know what your doing and I'll bet it works fine when your done.

[thecfarm]

Kellyj,I can give you his number and you can ask him. ;D  All I know is I went to the 007 and all the problems went away. I went through 2 pumps. Now the pumps last for years,instead of a month.

[Gearbox]

Kellyj I will disagree When you start a system you will need to push the water up to the heat exchanger fill it expel the air back inside the boiler then after that you have a closed loop . Now if you are in - 20 below zero and you have a 007 that will not expel the air back to the boiler and you are bleeding it out and trying to beat the frozen pipes . now do you see why I recommend a pump big enough to expel the air . Yes it is not needed till it is .

[Kellyj]

 

All I know is I went to the 007 and all the problems went away. I went through 2 pumps. Now the pumps last for years,instead of a month.

I can believe your problems went away, just cant see a circulator that is chasing a circle through a piping system, how it can make itself spin faster :

[Kellyj]

Kellyj I will disagree When you start a system you will need to push the water up to the heat exchanger fill it expel the air back inside the boiler then after that you have a closed loop . Now if you are in - 20 below zero and you have a 007 that will not expel the air back to the boiler and you are bleeding it out and trying to beat the frozen pipes . now do you see why I recommend a pump big enough to expel the air . Yes it is not needed till it is .

First, i'm not trying to start a arguement with anybody.

Here is 1 problem, that is not what a "circulator" is designed to do.   Yes, I know many people up here that do the same thing, and have the same complaints and problems.

Why are you not starting it till it is -20, like i said in a previous post, that boiler circulator needs to run 100% of the time that the boiler is heating, not on a call for heat.

Lastly, though you can put OWB lower than your heating appliance, you will have less problems if it is equal to or higher. Unless of course, you are making a pressurized boiler.

I repost my previous post, if you want to eliminate 90% of your problems with OWBs, put them equal to or higher than your heating appliance.

100% of the OWBs that i hooked up that are either equal to or higher than the heating appliance have 0 air issues. I also use a plate exchanger if hooking an open boiler to a pressurized boiler, again 0 air problems.

[SPD748]

No arguments, just great dialog and information. Thanks for the ideas and opinions guys! Keep them coming...

-lee

[Gearbox]

Pump goes out Draft solenoid sticks and boils over and anyone that has run one can add many more reasons . There boilers and there outside and you will have shut downs unplanned in in cold weather . Some where I live may happen at - 30 to 40 below zero . Any problem I can save someone problems for an extra $75 its cheap to freezing fingers in the cold .

[Kellyj]

Pump goes out Draft solenoid sticks and boils over and anyone that has run one can add many more reasons . There boilers and there outside and you will have shut downs unplanned in in cold weather . Some where I live may happen at - 30 to 40 below zero . Any problem I can save someone problems for an extra $75 its cheap to freezing fingers in the cold .

you never mentioned unscheduled breakdowns. that is a different discussion. I'm talking, you fire the boiler up in the fall, the circulator runs until you stop feeding wood to it.

Again, i say, that is why you put OWB equal to or above the heating appliance. Nothing worse than it is -20 your circulator dies, you lose your prime as we'll call it, you change circulator, and now (because a circulator won't push air) you have to fight to get that perfect equation of air out or your lines with a device that isn't designed to pump water only move it.

I'm not criticizing you, But over the last 15 years, i've seen all kinds of [I have typed a profane word that is automatically changed by the forum censored words program I should know better] installs with these OWBs, that work if everything is just perfect, where the non licensed installer said, "paper work says it will work"

Again, not trying to argue, just giving facts as i dealt with them.

[Gearbox]

Kellyj your right  sometimes in houses like mine short of filling the ground up 4 feet my boiler is lower than the shop heat exchanger and having a earth bermed walkout on a slab with a water to water plate in the attic is even with  the boiler . We sort of got off track . Like all build projects there will be trade offs . All we can do is try to help with pitfalls .

[SPD748]

Here's what I've learned so far:

- Level is better than the OWB being lower than the heating appliance (prime/air issues)
- It isn't a "pump", it's a "circulator" due to the closed loop arrangement thus the sizing calculations are unique
- No damper is required if the draft control seals tight
- The design needs to extract the maximum amount of heat from the burning gasses without cooling them to the point of creosote formation

That last point is where I think I am in this project. I need to iron out a plan for the firebox vent then move on to the next stage.

-lee

[Kellyj]

I guess we've all learned something then.

[thecfarm]

- No damper is required if the draft control seals tight
-lee

And that if is very important too.
There is a small well before the flappers of the blowers.The back one is the one that when I throw wood is sometimes a piece of small black wood will get thrown into the opening. Or maybe a bunch of small pieces will cause problems.This has caused the flapper not to close all the way. Don't take much air to make the fire go. As I said,if things are tight,just a little bit of smoke comes out of the stake at idle and when I open the feed door it should look black or looks like the fire is out.

[Holmes]

 I believe you plan on the water part of the boiler being an open vessel ? It does need to be open to the atmosphere , if not then it needs safety relief valves.  It can become an explosion hazard.  It does not have to be fully open, but at least a few uncapped 2" pipes may be all right. A runaway fire is very dangerous when heating water.  Like welding on a tire rim with the tire on it, deadly.
   Make your feed and return tappings 11/4" and valve them off at the boiler. It's easier to go in pipe size than up in pipe size.  Put a drain or 2 on the bottom of the boiler . Good luck.  I find this interesting.

[SPD748]

Holmes,

My boiler will be open to the atmosphere. I plan on having a fill tube welded into the top of the tank. 2 1/2" diameter or so. I'd much rather have a boil over than an explosion. I like your idea of making the pipe connections large. I agree that it's easier to reduce size. I can weld in 1 1/4" bungs. I think the normal arrangement is to pull water from the lower section of the tank and introduce water from the heating appliances into the top section of the tank. I was going to install a 2" drain at the rear of the tank.

-lee

[Kellyj]

A 2" drain? Are you building a 150hp boiler?
1" would be plenty, 3/4" is normal.

No explosions if you install a relief valve and some kind of an autofeeder on a closed/pressurized boiler.  It also eliminates alot of air problems and less worries if location is lower than your heating appliance.

Most of the preinsulated tubing is 1" or 1 1/4", so 1 1/4" bungs or thread-o-lets are good decision.

[SPD748]

A 2" drain? Are you building a 150hp boiler?
1" would be plenty, 3/4" is normal.

:D  1" it is then.

-lee

[Hilltop366]

I have been following along with interest.

Ideas:

It is nice to be able to hook a garden hose up to the drain on an indoor boiler, I suspect it would be nice to be able to on a outdoor one as well so you can drain the water away from your work area when working on the boiler.

Keep all inside pieces wet including baffles or smoke shelves so they won't warp and burnout.

Another baffle option, the baffle on my indoor boiler (1970's HS Tarm MB 55) is at the back and is vertical with a second air inlet at the bottom of the baffle, there is a cleanout at the top near the rear, a quick scrape once in a while and everything falls down to the ash bin. Link to picture, https://woodboilers.com/media/wysiwyg/Downloads/Product_Brochures/MB_Solo_Series_Brochure.pdf



No need to make the boiler bottom flat just make the cleanout shovel rounded to match the profile.

[Gearbox]

You are right on the pump mounted low . I would take water low on one side and put it back in high on the other side to set up a cross flow . Helps with hot spots .