Outdoor Wood Furnace Info
All-Purpose OWF Discussions => Plumbing => Topic started by: JD Jim on December 09, 2013, 11:04:06 AM
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I have been doing lots of reading on here, wonderful site, wish I had found it a year ago.
My question's is, are there any pictures of hot water tank and plate exchanger hook ups?
I rarely ever hire any work done around here, just find my way thru the maze, been living here for almost 40 years now, wired this place and done all the remodeling myself; but hooking up one of these systems is trying...I want it right the first time.
1. new 6048 140' from the house and 40' from the garage.
2. 24x24 HX in my hot air furnace plenum about 6-8' rise above boiler location
3. 20 plate for the 50 gallon hot water tank.
4. Thermo-pex buried in the ground 1"
5. 100,000 btu water to air blower in the garage, about 6-8' above the boiler.
Concerns are: pump sizes needed and
Best way to plumb this stuff so I can maintain it correctly with out dismantling the whole mess?
Pumps will be located on the boiler per CB's illustrations.
I'll be watching this closely and answering any questions you may have...thanks in advance.
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Here is my initial layout for what I built. It seems to work fine for me.
Your setup is close to what I put in last year. My house furnace is in the basement, so it is lower than the OWB so my pump is nearer the low point of the system in the basement and the distance shown on the attachment is about the right distance, Grundfos 26-99 pump, and a 17x22 HX heating about 4000 sf. I put a bypass and drain for the HX since its right after the A/C coil and must be drained in the summer (used ball valves w/a drain on them). Our house is normaly not above 70 in the winter unless the mother in law visits :-\.
I did modify my potable hot water and built a OWB HX bypass for the summer season (not shown on here). I also have an electric demand hot water heater, so no potable hot water storage in my system. I ran the electic hot water heater as a supplement last year, but have just shut it off this year and have never been w/out hot water. The house was full of extra family members at Thanksgiving and I lost track how many showers there were each morning (probably 10 minimum). I think that I have a 30 plate water to water HX. The 1" PEX valve shown in the house return line is the lowest point in the whole loop and why it is there. I figure I can get 95%+ of the boiler water out from that point if necessary. The electrical from the OWB to the house is an empty conduit right now, power comes from my shop elec panel.
On the shop loop, my heated area is 24x56x10 and it is about a 9-foot raise to the furnace HX (18x18 inch) so I ended up installing the pump on the back of the boiler for that application instead of how it is shown here. That pump came with the Shaver furnace and I think its Armstrong's mid size pump (Astro 250?). The 75-foot run shown is longer than as built, I relocated the OWB and it is closer to 50-feet as built. I also did not put the bypass on this furnace since the HX is above the OWB and I don't have A/C there (yet). I installed a vent at the high point and can just drain that part back to the boiler if I ever need to or if I add A/C to that furnace in the future and need to drain the HX in the summer.
I am very happy w/my system. Good luck w/your build!
I did not find this site until after my build and built my own underground lines, 6 wraps of techfoil around 2 ea 1-inch Pex-AL-Pex lines.
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Your setup is very similar to mine, I have a 5648 (older equivalent to 6048) with 130' 1 1/4 thermopex. I inherited the system so didn't do it myself but my supply and returns run into 4 port 1 1/4 to 3/4" headers. Not many people use the header/manifold setup that I've heard about. I am running 2 furnace HX, sidearm HX on 50 gal tank, and a a basement baseboard and 50k BTU garage heater with no problems. My pump is a Taco 011.
Did you plan on using your 50 gal tank for storage before or after the 20 plate? I've read about people doing both. Alternatively you can just use the 20 plate without plumbing in your tank, in an "on-demand" setup-- lots of people do that too.
As far as best way to plumb just make sure you plumb in bypasses for everything so you can isolate the 'appliances' if they need serviced. Generally you want your domestic hot water to have your hottest supply so plumbed boiler -> 20 plate ->furnace -> garage -> return. I'm not a pump expert but you'll want at LEAST a taco 011, prefereably 013 or 2400-20-WB. Someone with more knowledge might have better pump suggestions
Is your garage going to have a seperate run from the boiler or in line with the rest?
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Separate line to the garage 40' away.
I plan on making it so I can service the HX in the plenum for cleaning purposes, so all I would need is unions in the copper lines next to the exchanger and I also want to be able to bypass it when the weather is warm for a 2 day stretch?
I should have mentioned I have a Taco 007 on the line to the garage and bought the new Taco 2400-20-WB for the house loop......but is it too much pump?? I just can't trust salesmen any more....that's why I find myself in this predicament....had 2 007's ready to hookup and then went to reading and made a call to order the exchangers....good money after bad???
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Wood Nutt, That's awesome pdf, exactly what I am looking for....I need to figure out how to use that to lay out my plans before I go off buying up the plumbing shop, and then returning what I don't use.
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Separate line to the garage 40' away.
I plan on making it so I can service the HX in the plenum for cleaning purposes, so all I would need is unions in the copper lines next to the exchanger and I also want to be able to bypass it when the weather is warm for a 2 day stretch?
I should have mentioned I have a Taco 007 on the line to the garage and bought the new Taco 2400-20-WB for the house loop......but is it too much pump?? I just can't trust salesmen any more....that's why I find myself in this predicament....had 2 007's ready to hookup and then went to reading and made a call to order the exchangers....good money after bad???
Right just use unions. Also plumb in a bypass for each applicance. For a bypass you just need shutoffs on supply and return and a shutoff on the bypass leg.
The Taco 007 can only do 10' of head. all fittings and pipe length add to your head (plus your 6-8' of rise) so that may be just about enough for your garage loop but its close. I'd say the 2400-20-wb would be good, from everything I've read the faster the water moves the better. The Taco 007 defintitely is not close to enough for your house loop. Again wait for someone smarter than me :)
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Marty,
I will use the tank after the exchanger for storage.
What's the best way to fasten up a plate exchanger for support other than the lines?
on the pumps...
That goes to show you what my CB dealer knew about hooking these up, lol....I shot all kinds of holes in there hookup estimate so far.
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Marty,
I will use the tank after the exchanger for storage.
What's the best way to fasten up a plate exchanger for support other than the lines?
on the pumps...
That goes to show you what my CB dealer knew about hooking these up, lol....I shot all kinds of holes in there hookup estimate so far.
Tank after exchanger will work well if you have a lot of hot water use (otherwise water in storage will be cooling). Otherwise you may get hotter water from directly plumbed on-demand setup.
I've seen some pictures on here-- I think people generally mount them vertically and strap them to a wall. Also people seem to pack them in rigid foam insulation.
I recently added my finished basement garage loop which was an additional 150' of 3/4" pex and 10' of head and my 011 handles all of it. an 011 would probably be fine but I don't think the bigger pump would hurt. I actually plan on getting the 2400-20-WB and replacing my 011 with it, and keeping my 011 as backup. I think I'll get a bit less heat loss with that pump.
Here is my diagram:
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I mounted a piece of plywood with 4 long carriage bolts (longer that the plate HX is deep) sticking out. I then put two aluminum c-channel straps across the HX. Anywhere there was metal to metal contact, or close, I put a strip of rubber between. I built a closed cell foam box around it but never have figured out an easy way to put a front on it due to all of the water lines protruding from it. You can see the HX in the upper left of the attached photos. You can also see the summer potable water HX bypass in this photo (and the top of my electric demand hot water heater).
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:post:
Ideas, ideas, that's what I am looking for here....anybody else care to post some pics of there setups?
I always say 2 minds are better than one.....
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One of my concerns is the heat generated off the plate exchanger. It along with the hot water tank, and deep freezer are located in the same small unheated room that my lines come through the block wall from my boiler. So I believe, but don't have any experience with a plate exchanger, just how much heat will there be, trying to keep my deep freezer in a cooler room which this one is in the winter time.....it's my old storage area for 1/2 cord of firewood that I feed to my indoor Brunco furnace. Never thought about a box of Styrofoam. This small unheated room is just 4' thru a door, from my old furnace, where my HX will be in the plenum.
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One of my concerns is the heat generated off the plate exchanger. It along with the hot water tank, and deep freezer are located in the same small unheated room that my lines come through the block wall from my boiler. So I believe, but don't have any experience with a plate exchanger, just how much heat will there be, trying to keep my deep freezer in a cooler room which this one is in the winter time.....it's my old storage area for 1/2 cord of firewood that I feed to my indoor Brunco furnace. Never thought about a box of Styrofoam. This small unheated room is just 4' thru a door, from my old furnace, where my HX will be in the plenum.
My furnace/ hot water heater area is pretty hot when the furnaces are going. Theres a lot of exposed copper radiating heat. That said, if you insulated real well you should be fine. Which would be a double advantage for you.
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Marty said hot water should be plumed first before the furnace. How much does that take away from the
furnace. I'm going to use a 20 plate for the hot water and a 50 plate for the hot water boiler.
What do you guys suggests a on demand and or plate before hot water tank?
And is a 50 plate big enough for 194000 BTU hot water boiler?
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It only takes away enough to keep the hot water at a more consistent temp. Explanation- if it was after the furnace and you were in the shower with water temp set and the furnace cuts on and drops the water temp. 20 degrees so you turn a little more hot water on........boom furnace cuts off and hotter water again. So before the water heater tends to act as a buffer and deliver more consistent temps.
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Gotta have a diagram like Marty Drew. With that I would calculate the btu's needed and thus how many GPM required to provide those btu.
So a side arm= 60kbtu = 6 GPM
2-140kbtu AH's= 280kbtu =28 GPM
Kicker. = 20kbtu. =2 GPM
Garage HE. = 47kbtu. = 4.7 GPM
Total = 407kbtu. = 40.7 GPM
Now we need to size headers and underground lines to supply 40.7 GPM = 2-2" pex or 2" copper or 12-1" pex S&R, 8-1.25" pex for S&R, 6-1.5" pex for both S&R..
Its a lot of BTU to supply to make everything work to its design spec. How do you control each device when it's not calling for heat.
http://www.taco-hvac.com/uploads/FileLibrary/SelectingCirculators.pdf (http://www.taco-hvac.com/uploads/FileLibrary/SelectingCirculators.pdf)
http://s3.pexsupply.com/manuals/1322593690235/68978_PROD_FILE.pdf (http://s3.pexsupply.com/manuals/1322593690235/68978_PROD_FILE.pdf)
Let's just say we use one set of 1" lines like the plan, max btu supply is just under 80kbtuh@4'/sec. Around 9' of head just from boiler to manifolds. So a circulator that'll do 8gpm@9' head. Ah look a cheap 007 or 15-58 would do it. Now if there was a hydraulic separator between boiler and manifolds, it could be zoned several ways. If not then we have to add the longest loop or loop with highest head to the boiler loop and recalculate. But in this case how do we control flow to each device.
There are many ways to design a supply, it's which option suits your house
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Sprinter, I think your math is a little off on Pex S&R - cause remember you can run Pex close to 8'/sec and not have to worry about erosion. With that being said, assuming 41GPM required in worst case scenario on coldest day;
2" Pex is capable of 52gpm @ 8'/sec (with head loss of about 11.5 feet/100')
1.5" Pex is capable of 30gpm @ 8'/sec (with head loss of about 15.4 feet/100') Would required 2 S&R
1.25" Pex is capable of 21gpm @ 8'/sec (with head loss of about 17.9 feet/100') Would required 2 S&R
1" Pex is capable of 14gpm @ 8'/sec (with head loss of about 22.5 feet/100') Would required 3 S&R
However sprinter I do agree all this is for naught, depending how the system is designed/zoned.
Also, if 40+ GPMs are required would recommend some, primary-secondary piping, so main loop has the least amount of restrictions
NOTE: If your system requires +400k btu/hr :o what do you feed the beast (OWB), and how often!?!
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No you shouldn't run 8' per second. Erosion is one thing, but more importantly look at how the head climbs exponentially as you exceed 4' per second. Either way there isn't a designer anywhere that would recommend that kind of velocity. Trunk slammer design, just because it can doesn't mean you should. My numbers are the same numbers found in any hydronic design book or program. So instead of using a economical 007/15-58 you now need a much larger $300-$400 circulator that is beyond design, burning several times more electricity , and masking wrong pipe size. No wonder we see so many circ failures. Not to mention many hydronic devices are not intended to see those velocities. That's enough to push open zone valves, premature failure of air vents and so on, and create cavitation. A lot goes on when you start and stop fluid at that speed.
It starts a chain reaction, a lot of it unseen until problems start showing up, and they can't figure out why. But somebody will find something to blame.
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Yes, little John, I was being facetious with the first post. That would be true if everything is calling at the same time. However when broken down into a pri/sec off a small buffer tank and zoned. You can properly feed each zone. Just like on controllers with a priority zone for indirect water heaters, it will temporarily shut everything else off and just feed the tank, mine takes about 15-20 minutes at 180-200 deg. Then that's done for the day, cuz that's a 120kbtu load and would take a couple hours with other zones calling. Also if a outdoor reset curve controller is used much lower temps can be used, further decreasing the load. I have unfortunately seen some like this in one big loop or two. Have you read the glitch and the fix in plumbing and mechanical magazine? It's written by another John, Siegenthaler. Pretty good stuff for troubleshooting and design.
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Sprinter, I also apologize :-[ - what I should have said was, you COULD run at 8'/sec not you CAN or SHOULD.
Again it gets back to the math, and yes - you run at or near the recommended limits of a product but there are certain consequences is doing so; and with hydronic system higher velocities equals higher head pressures.