Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: dirtdigger on September 07, 2014, 04:54:48 AM
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I'm getting too old to remember anything anymore, how do I tell how large of plate exchanger I have now, I can't remember what the plate count was or btu rating its at and I can't read the tag on it anymore, even with a magnifying glass.
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What are the measurements?
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I measured it, its roughly a foot long, seven inches high and about 4.5 inches wide for the measurements on the plate portion itself, not including the piping that comes out the top.
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1 inch or 1 1/4 inch ports?
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I'll have to check it in tomorrow, I don't recall.
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One inch pipe on the plate heat exchanger and I reduced it down to one inch pex for my line from the furnace.
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The 7 inches part has me a bit intrigued, 50 plate is as large as I have seen with 1 inch ports, but they are not typically that deep
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Too long ago to remember for sure but I was thinking something like 80 plate and thinking in that 300k neighborhood???
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The 7 inches part has me a bit intrigued, 50 plate is as large as I have seen with 1 inch ports, but they are not typically that deep
I can get up to 100 plate with 1" ports. Sounds like it is somewhere in the 60-80 plate range.
BTU ratings on plates doesn't really mean much. It will be completely different depending on the type system you are using it for. If you are heating domestic water that enters the plate at 50 degrees, the same plate hx will transfer many times the BTUs that it would running in a baseboard heat system there the secondary side it not much lower temp than the OWB side.
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My shop has infloor heat in both the office and main shop, the shop is put in an old barn that was remodeled, the entire floor is setup on a slope from one end to the other to make it work and be able to enter the main door, then there is a full service pit in the main shop that's 50 feet long and six feet deep, also on with a sloped floor from one end to the other.
I wanted antifreeze in the entire building, including the office/break room attached to the shop, so it was decided to install a hot water heater, to be used as a holding tank, not to heat anything, but we put in the plate heat exchanger and have a pump set up off the thermostat on one of the heating elements to start and stop the pump to maintain the temp in the tank. We also pressurized the tank and system in the building to try to equalize all the zones so they could pump and circulate equally and in order to do that we used the plate heat exchanger to isolate the furnace which isn't pressurized to the shop which is.
Last winter was the first winter we heated the shop, but we've been heating the office/break room for a couple years, along with the house for quite a few years. Then along comes last winter's bitter extended cold and my furnace couldn't keep up and keep everything warm, so after a couple months of going through the whole equation, it was finally discovered that the blower motor wasn't the correct one for the furnace, which has just been solved.
My main question was this, is my plate heat exchanger large enough to do the job of heating the shop and office, total footage of the shop is about 2700 feet but the main shop has 21 foot ceilings, all fully insulated, but the kicker comes into play when I talk about shock cooling the shop when I open up the large door on the end of the building that's 20 feet high by 34 feet wide and its a one piece hydraulic door that opens up, then we bring in equipment to the tune of 30-70,000 lbs to warm up and work on during the winter's off season.
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That's an awful lot of space to reheat quickly, square footage for heating is typically figured with 8 foot ceilings, therefor you are actually heating almost 3 times your floor space, 3 times 2700=8100 feet
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slimjim, so is my plate heat exchanger large enough to do the job, or do I need to do something different before the heating season kicks in full swing?
All the local "experts" tell me I only need 60,000 btu's to heat the shop, ceiling height means nothing in the equation, which I'm finding very hard to believe and swallow, so we did as they said and insulated it better for the coming winter and got my wood boiler back up to par, supposedly/hopefully.
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60,000 BTU, what the heck are they smoking? You should be fine with the exchanger, I would be a bit concerned about flow so eliminate any close 90's
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dirtdigger,
I'm thinking like Slim its way to small. I'd say you need 200,000 btu or more. Just saying. Don't undersize yourself or when you open that big door it will take a long time to recover.
Greg Steinacher
618-401-0726
www.midwestoutdoorfurnace.com (http://www.midwestoutdoorfurnace.com)
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While on the subject of in floor heating, I'm also told that about 25 btu's per square foot of floor space from my in floor heat, is this accurate? If so what else do I do to add supplemental heat, a forced air radiator/blower or an added heat source of something else entirely?
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The calculations on the BTU's per foot can vary dramatically without a real drawing of how the floor was laid out, also the heat the slab will dramatically change from how the insulation is done, most folks insulate under the slab and skip the sides, the sides are where the majority of your heat is lost, some guys say as much as 80% of the heat loss on an uninsulated slab is lost horizontally to the frost outside.
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dirtdigger,
I guess I would wonder first if your Outdoor furnace is big enough to handle more load on it. If it is I would mount a heat exchanger with fan (air handler) up high out of the way and blow down in the room. You can put this on a in-line thermostat and just plug it in if you have a receptacle close!
This would help you recover after the door is opened too.
Greg Steinacher
618-401-0726
www.midwestoutdoorfurnace.com (http://www.midwestoutdoorfurnace.com)
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Been around a few that didn't insulate very well around the foundation, in the dead of winter with below zero temps the grass was green and growing outside the building. Mine we insulated to the hill, both under, around and there's a foot of fiberglass blowin in the walls, we've done heat gun temps of the wall and surrounding area's, all are like they are supposed to be behind the insulation and the wall itself.
I've considered a forced air radiator style setup for quick recovery, but with the house already online I'm not thinking my wood boiler can do anymore, but this winter should tell us more. We've considered a chip boiler to go along with a wood boiler, but for the costs associated with them all, its looking doubtful. I'd probably opt for a larger firewood boiler that would be new and keep processing firewood.
We're also getting setup for lp gas in case this winter is another repeat of last winter, to aid us out in times of extreme cold and if or when the wood boiler won't keep up.
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Dirtdigger, I have the exact stove that you do, I now use it for backup only when away from home doing shows with the chip boiler, I am telling you that your issue is not the boiler, you may have a problem with the blower but the boiler WILL do the job, your problem is in the install, may I ask what you ran for pipe, size and have you ever checked heat loss on it? I would love to put you into our chip boiler but it will do the same thing as your Wood Doctor if the pipe is junk!
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My outdoor boiler is maybe 50 feet from the shop, we put the foam insulated two one inch pex in a four inch tile buried to the shop, there is no bends, elbows or anything in the line, we buried the same type of line to the house, which is 150 feet from the boiler. In the shop it goes into the plate heat exchanger and back out again, there are two elbows in the plate heat exchanger on the shop side to the water heater, nothing but straight in and out on the boiler side, there is a pump on the back of the boiler that pumps to the shop, another pump does the house.
When we've done the heat loss with a temp gun, maybe not accurate enough, but the temps were close, less than five degree's from the boiler to the house, and less than that to the shop.
We are in a wet area of the state, I installed drain tile a foot deeper than the boiler lines, and some more tile shallower than the lines, the lines themselves are at the six foot depth, mainly because its what the angle it took to get under the shop footings with the bend radius, and the same at the boiler. As for the brand, I'm not remembering right off, but its the same as everyone in the area has used no matter the brand of boiler installed, all the plumbers and boiler sales people get the same brand, I know I asked at the time.
I should have gone with a larger line, but if we'd do a radiator with a fan to add a faster recovery when we open the door, I'd run another line still for that unit alone with another pump to run it.
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It sounds like you have done it all correctly, can you tell us actual inside pipe size on the underground pipe as well as what you are using for circulators and how they are oriented, pictures will help a lot.
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Pipe size is once inch pex, pictures I'll have to have the kids attempt that this weekend, that's out of my league completely, I can type on the computer and that's about it. I'll caliper the fittings and pipe to get you the exact measurements.
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Thank you, I just can't believe the boiler is the issue, mine has done an awesome job heating my uninsulated shop and 3000 foot home for so many years!
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I was wrong, there is a 90 degree elbow in the line from the shop the furnace, its viable in the photo if they come up on here.
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Wrong still again, two per line, one in the shop and another by the furnace, the first photo's show the shop and plate exchanger that's not been cleaned off since we foamed the walls a couple weeks ago, the line coming up into the shop is now behind the tin and insulation of the office break room.
I haven't calipered the line but I'm sure its one inch pex, we got the fittings at Menards and some from the place we got the insulated line from.
I'd have to check the model number on the pumps, but they are all three speed pumpgs, gruntfos is the brand, might not have spelled it right, but close enough.