Zodiac45
Paleostoveologist & Sawwhisperer
How much water are you heating and what size is your firebox?
OWB Project
- Thread starter Stihl310
- Start date
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I have an 19 cubic foot firebox heating approx 145 gallons of water.
Guess I was just going with what I had seen on other boilers. CB appears to be pumping out of the hot. Aside from that the water temp is only going to be at the most 10-15 degrees cooler going back into the burner. The reason I don't put it in the basement is because of the amount of head pressure I would incur from doing so, about 12 foot more of head pressure by doing it this way. This would make me have to jump to a much larger pump which I really didn't want to do.
Like I said I'm going with what I have seen before, there seem to be many manufactured units that are pulling out of the hot water and are mounted right on the unit.
You'll be OK, I'm just an old pessimist. Since you're starting with a clean slate it's nice to stack every card possibile in your favor. Head isn't just a column heighth, it's more like resistance to flow at a certain GPM. I could be wrong but I think head (resistance to flow) could be calculated for your boiler loop without regard to pump location. I wish you the very best of luck on your project. DIY is a great learning experience. I know there were some real learning curve moments when did my install. Now how about increasing the R30, you will have a delta T of nearly 200 degrees at zero and that sir is a bunch.
I calculated the actual head on the system to be around 11.5 ft. Had I placed the pump in the basement I would have added anywhere from 10-12 ft of head pressure on top of the already existant 11.5. Getting me somewhere around 20 ft of head pressure, in turn bumping me up to a much larger pump.
I'm dumb on the Delta T stuff... please explain that to me... 200 degrees at zero???
Delta T is temp diferential. Boiler at 200 outside air at zero----Delta T is 200. Should be cheaper to add insulation in the begining rather than later. I fail to see how switching the location of the pump can almost double the head. But then I'm not a professional.
You stated it in your last post "head isn't just a column height"... Yes it is resistance to flow due to drag created by the loop... and from my understanding it is also vertical height above the pump.
Here is a quick explanation from a website:
First, determine the lift or height the pump will need to move water. If the pump draws water from a reservoir below the tank, measure (in feet) from the pump to the point water returns to the tank. This will be your initial head pressure in feet.
From what I understand head pressure is a combination of "actual" which I would consider the vertical lift the pump needs to put out to get the water to where you want it to go, and then the calculated head which is head pressure incurred from the drag created by the fittings and line loop.
As far as insulation goes? What R value do you think I should go with? I was going to wrap the tank with alumnium faced fiberglass and then wrap it in R-30 batts. I could add multiple layers if I needed to. Just curious if there is a set in stone R value I should go with?
Thanks
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Nothing set in stone, whatever is workable. I started with an existing junk OWB and just skinned it in junk siding. I think this year I'll remove the skin and build it out using steel framing studs to get a bit more R value.
Thats what I'm planning on doing, I was going to build a steel frame all around it with angle, but it's much cheaper to go the steel stud route, no welding either... and it's alot lighter.
Lloyd H
ArboristSite Operative
pump location
You have the pump right where it belongs. Read Dan Holohans book "Pumping Away" Pump head would be the same with pump in the basement but the only plus would be frost protection for pump in case of extended power outage. I would replace the nipple upstream of the ball valve with a dielectric nipple (steel nipple with plastic inside ie. a water heater nipple) and the nipple downstream of the ball valve with brass as well as a brass pump flange seeing as how you have a brass pump. You now have 3 junctions of dissimilar metal, two on the ball valve and one at the pump, with a few bucks you can eliminate all three. Use a brass flange on the output side of the pump as well with a brass or copper pex adapter. A ball valve on the output side of the pump is also handy for pump service. On the return use a steel pex adapter or a dielectric union. It is always best to avoid dissimilar metals touching in a system.
You have the pump right where it belongs. Read Dan Holohans book "Pumping Away" Pump head would be the same with pump in the basement but the only plus would be frost protection for pump in case of extended power outage. I would replace the nipple upstream of the ball valve with a dielectric nipple (steel nipple with plastic inside ie. a water heater nipple) and the nipple downstream of the ball valve with brass as well as a brass pump flange seeing as how you have a brass pump. You now have 3 junctions of dissimilar metal, two on the ball valve and one at the pump, with a few bucks you can eliminate all three. Use a brass flange on the output side of the pump as well with a brass or copper pex adapter. A ball valve on the output side of the pump is also handy for pump service. On the return use a steel pex adapter or a dielectric union. It is always best to avoid dissimilar metals touching in a system.
Good info, thanks... I may just do as your saying and replace those. For all the more it would cost. I have a generator so extended power outage isn't a concern. I do have brass flanges on the pump right now, it may be hard to see in the pictures. I also have a ball valve that will be installed below the pump, just haven't had time to get it hooked in yet.
Sorry to give you confusing advice. I've heard Holohan's book is a good one. In Taco's install instructions they don't recommend installing a pump with that orientation. Press on regardless. Good luck.
I guess I don't know what your referring to, in the instructions all it says is to mount it in the horizontal position unless the system is pressurized to a minimum of 20 psi?? On the Central Boilers they have the pumps mounted in the exact same fashion, right on the side pulling the hot water out... It seems I can't figure out the right way to mount it because every manufacturer and every custom fab job I've seen mounts it in a different position.
It was discussed on another forum a week or two back and the directions from Taco did not recommend the pump discharge downward. The only reason anyone could think of was bleeding air wanting to rise against the flow. Your post had me thinking about any ways I'd change my system and here are a couple ideas. I'd move everything possible indoors. The only thing required outdoors would be the solenoid that operates the intake air or blower if you use one. Aquastat, pumps, all indoors with easy access. One wire to the boiler from the aquastat and a couple isolation valves on the boiler. I run constant circulation so the aquastat location wouldn't matter. If your boiler ever went bad or you wanted to redesign something all the controls could remain in place.
I'm mounting my aquastat inside, maybe even in my bedroom so I can keep an eye on it all night. Seems alot easier to do it this way. I am ordering dielectric fittings for the pump. It never even occurred to me that I should do that, better now than later.
<<<One point about the pump. I do not know if your OWB is open or pressurized. I hope its open and non-pressurized. At any rate, in a non-pressurized open system, an issue with Taco type OWB pumps is that they tend to cavitate in low pressure systems. Cavitation causes them to fail pretty fast. So to avoid that, you want to place the pump at the lowest level in the OWB water loop, so that hydrostatic pressure is higest in the pump itself. The lower the pump, the higher the water pressure will be there. More pressure, less cavitation, and the pump will last longer. As far as flow goes, the pump will drive the water in the loop wherever it is located.>>> This was posted by windthrown on another thread. Honeywell does make an aquastat with a nite lite be sure to order with the NL suffix on the model number.
See recent post by windthrown on OWB install I tried to cut and paste the quote but it didn't come through. He says pump belong at lowest point in the system.
Hortonboy
New Member
OWB Choices
I've paid my last LP bill and diving into the OWB market. I'm down to two wood burners... the Greenwood "Aspen" and Central Boiler "E-Classic". My biggest factors are efficiency, low emmissions and least amount of wood for my heating needs. I have about 2,700 sq ft I want to heat along with a two car garage and an eventual green house/poll barn. I'm a little confused on what makes one better than the other. I'm leaning toward the Aspen since it meets phase II emissions requirements and they claim to use 50% less wood. Anyone have either of these units or can offer their expert opinion? Thanks!:chainsawguy
I've paid my last LP bill and diving into the OWB market. I'm down to two wood burners... the Greenwood "Aspen" and Central Boiler "E-Classic". My biggest factors are efficiency, low emmissions and least amount of wood for my heating needs. I have about 2,700 sq ft I want to heat along with a two car garage and an eventual green house/poll barn. I'm a little confused on what makes one better than the other. I'm leaning toward the Aspen since it meets phase II emissions requirements and they claim to use 50% less wood. Anyone have either of these units or can offer their expert opinion? Thanks!:chainsawguy
Seems like everyone has a different opinion... I'm not sure what to do anymore....
....Well it's been awhile since I posted any updates on my woodburner... as of yesterday I now have my door completed, blower fan in place, and damper set up... I started a small fire in it in my garage:jawdrop: just to get some smoke rolling to verify the seals on door and door panel. Everything looked good and when all was sealed up it really killed the fire, and when that blower kicked on it was like a torch. All I have left to do is put the well in for my sensor and get it out of my garage.
Here are some pictures, I crawled inside of it to check that the door seals were good, and of course my wife had to take my picture when she opened the door back up....
Here are some pictures, I crawled inside of it to check that the door seals were good, and of course my wife had to take my picture when she opened the door back up....
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