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Author Topic: Adding a branch to heat a workshop  (Read 3185 times)

joehust

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Adding a branch to heat a workshop
« on: January 15, 2018, 06:18:59 AM »

I have a CB E-Classic 3200 that is heating my house and my Dad's house with no issues.  It was installed professionally a few years ago and there are two Taco 007 circulator pumps out at the boiler pushing water to both houses through 1 1/4" underground, insulated PEX that then ties into both indoor boilers.  I am now going to extend an underground 1" insulated PEX line that will go out the other side of my Dad's basement and run about 80 feet to another building that I would like to supply some heat to.  My question(s) are related to how to plumb that line from where the 1 1/4" pex currently comes into my dad's basement and enters his furnace.  I plan to take a branch off the 1 1/4" PEX at some point after the thermostatic valve that is just inside my dad's basement wall (which returns the water back to the OWB if it drops below a certain temperature (150 maybe?).

1) Do I just split off the 1 1/4" with a tee to run the 1" out to the workshop?

2) Do I bring the 1 1/4" into a header (or manifold) in my dad's basement and then run it to both his furnace and the line that goes out and to the workshop?

3) Ultimately, I think i would feel better about running into a plate heat exchanger for my Dad's furnace instead of going straight into his furnace and having to de-pressurize his system every winter.  If I did that, should I first go to the HX for his furnace and then go to the workshop (running them in series), or should I still split the line having it go to both the HX for his furnace and the workshop (in parallel)?

4) Depending on which option is chosen, would I need another circulator pump to move the water through the workshop and back?

Thanks in advance for any advice.
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wreckit87

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Re: Adding a branch to heat a workshop
« Reply #1 on: January 15, 2018, 10:24:15 AM »

How far is it currently from the boiler to your dad's indoor boiler, or what is the total loop length approximately, as is? Do you know if it's 1-1/4" Thermopex from Central Boiler or is it something else? The Thermopex is actually a true 1-1/4" inside, while others are only 1" inside but marketed as 1-1/4". I would definitely install a plate exchanger in the loop to avoid running OWB water through the indoor unit. What will the heat load be in the additional building? Those thermostatic valves are pretty picky- I can imagine you are getting close to the 150 at the bottom of the cycle already with the house calling and that small pump, so if the other building has any heat load you may not get any heat through the TV. If it were mine, I would tee into the 1-1/4" inside the house with closely spaced tees and add a pump (possibly the 007 from outside and replace the one out there with a bigger one) to serve the new building. There are a lot of variables here in therms of heat load in each building, square footage, pipe loop length, actual pipe size, and type of heat within each building (baseboard, radiant floor, forced air, etc). I would guess you will likely need to upsize the pump at the boiler to keep enough flow for both buildings through the main loop. 007 is quite small for any amount of distance/head loss
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smithbr

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Re: Adding a branch to heat a workshop
« Reply #2 on: January 15, 2018, 10:41:11 AM »

Just a comment, wreckit might disagree, in which case I bow to him.
When my installer put my system in, I indicated I might want to add a load at some point.  Either a garage heater, or a greenhouse heater.  He put in a pair of Tees where the 1 1/4"CB Thermopex enters the house; those Tees feed the TV for the house on one side, and a pair of valves on the other(capped, obviously).  When I want to add a load, he advised that I then plumb the load in on those Tees, and put a TV at the target end of those pipes, followed by a water-air heat exchanger in a blower unit; that way, the water circulates continuously, and a thermostat would control demand in the garage.  He really, really, really wanted to keep the house heat separate from the garage.  Not sure if this will work for you, but I'm glad I asked when he was doing the work.
smithbr
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wreckit87

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Re: Adding a branch to heat a workshop
« Reply #3 on: January 15, 2018, 10:52:35 AM »

Just a comment, wreckit might disagree, in which case I bow to him.
When my installer put my system in, I indicated I might want to add a load at some point.  Either a garage heater, or a greenhouse heater.  He put in a pair of Tees where the 1 1/4"CB Thermopex enters the house; those Tees feed the TV for the house on one side, and a pair of valves on the other(capped, obviously).  When I want to add a load, he advised that I then plumb the load in on those Tees, and put a TV at the target end of those pipes, followed by a water-air heat exchanger in a blower unit; that way, the water circulates continuously, and a thermostat would control demand in the garage.  He really, really, really wanted to keep the house heat separate from the garage.  Not sure if this will work for you, but I'm glad I asked when he was doing the work.
smithbr

Not sure I follow. He put a pair of tees in the supply line prior to entering the TV? Or one on each supply and return line on the boiler side of the TV, with another TV for the garage loop? If I'm following correctly, that would also work well. Part of the reason I was asking about BTU load in this new building and such; if it's just a small building he should be able to run it easily through the same TV, but I do see the benefit in running a secondary TV if the load is big
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smithbr

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Re: Adding a branch to heat a workshop
« Reply #4 on: January 15, 2018, 11:02:02 AM »

Yep, I wasn't clear.  A Tee inbound, and a Tee outbound.  House on one side, garage on the other in both cases.  The reason he wanted a TV on the other loop is the same reason we put one on the house side; allows the furnace to recover unloaded, if the water drops below 150-ish.  Agree with you, if the load was small, the TV might not be warranted; in my case it is.
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joehust

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Re: Adding a branch to heat a workshop
« Reply #5 on: January 15, 2018, 12:29:41 PM »

Sorry, the two circulator pumps at the outside boiler that feed my house and my dad's are actually Taco 009-BF5 pumps.  The distance from the outside wood boiler to my dad's basement is just under 50 feet.  It is then about another 100 feet over to the workshop (25 feet across my dad's basement and then another 80 feet underground).  As far as the heat load at the new building, I have not attempted to calculate that, but it is basically a small old deserted one story house (with a basement) that I finally bought and am putting to use.  It is approximately 24 feet by 48 feet.  I have basically gutted the house and am using it for storage and a growing workshop.  I am working on improving the envelope (tore off old faded siding and replaced with Tyvek and board-and-batton, adding insulation on the inside.  I don't envision ever wanting/needing it to be terribly warm in there, but keeping it above freezing with the ability to get it up to 50 or 60 when I want would be great.  Oh, and the underground thermopex is from Central Boiler.
« Last Edit: January 15, 2018, 12:36:21 PM by joehust »
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wreckit87

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Re: Adding a branch to heat a workshop
« Reply #6 on: January 15, 2018, 02:22:18 PM »

Sorry, the two circulator pumps at the outside boiler that feed my house and my dad's are actually Taco 009-BF5 pumps.  The distance from the outside wood boiler to my dad's basement is just under 50 feet.  It is then about another 100 feet over to the workshop (25 feet across my dad's basement and then another 80 feet underground).  As far as the heat load at the new building, I have not attempted to calculate that, but it is basically a small old deserted one story house (with a basement) that I finally bought and am putting to use.  It is approximately 24 feet by 48 feet.  I have basically gutted the house and am using it for storage and a growing workshop.  I am working on improving the envelope (tore off old faded siding and replaced with Tyvek and board-and-batton, adding insulation on the inside.  I don't envision ever wanting/needing it to be terribly warm in there, but keeping it above freezing with the ability to get it up to 50 or 60 when I want would be great.  Oh, and the underground thermopex is from Central Boiler.

Ah, with a load like that I would lean toward a setup like Smithbr has. 1-1/4"X1" tees on the supply and return between the wall and TV. Then a second TV in that 1" lineset going to the workshop, with an extra pump in that loop constantly circulating. This should split the heat evenly between both buildings without shocking the boiler. Maybe just keep a forced air furnace/air handler in the workshop with an Air/Water heat exchanger in the plenum? Shouldn't take a ton of heat. In that workshop loop, you'll have about 10-11 ft of head which is maxed out for an 007. Probably going to want something like an 0015 (3 speed) if you're stuck on Taco. Personally I don't like the 009 for a short loop like you have, as they are a high head low flow pump and you would benefit from more flow since your loop is short. Another option would be to put the 009 on the workshop loop and a new 011 or 2400-WB (or Grundfos 26-99, maybe B&G NRF-36, both 3 speeds which are handy) on the boiler to bring some flow through the loop. I run red pumps on everything, but since you already have the 009 there I would think my second option would be most beneficial for you. You have the big line, might as well use the extra flow capability to your benefit
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E Yoder

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Re: Adding a branch to heat a workshop
« Reply #7 on: January 15, 2018, 03:03:49 PM »

I agree with wreckit, big Pex with a 009 is kind of a mismatch situation. Not really utilizing the large piping.
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joehust

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Re: Adding a branch to heat a workshop
« Reply #8 on: January 16, 2018, 08:19:26 AM »

OK, thank you for your time and advice.  Just to make sure I understand this correctly ... I am running ~50 feet from the OWB into my Dad's basement through 1 1/4" Central Boiler thermopex.  I will go into a 1 1/4" x 1" x 1" (I guess) tee just inside the basement wall and run one side of the tee through the existing TV and to my Dad's boiler about 10 feet away (ultimately to a plate exchanger that I suppose I would have heat up the water being returned into the bottom of my dad's boiler) and the other side of the tee will go across my dad's basement and over to the workshop (~100 feet) where it will go into it's own TV before going into some type of heat exchanger over there.  I should not rely on the circulator pump at the boiler to drive both of the loops, but it will continue to drive the side of the tee that goes to my Dad's furnace?  I would put another pump (running continuously) on the other side of the tee in the loop that is going over to the shop.  Disregarding the Taco 009 that I already have, could you tell me what brand/size pump you would put at the OWB (or would you move it into the basement away from the OWB?) and what brand/size pump you would put on the loop going over to the workshop (and where would you locate that pump?)?  Thanks again!
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wreckit87

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Re: Adding a branch to heat a workshop
« Reply #9 on: January 16, 2018, 09:12:27 AM »

OK, thank you for your time and advice.  Just to make sure I understand this correctly ... I am running ~50 feet from the OWB into my Dad's basement through 1 1/4" Central Boiler thermopex.  I will go into a 1 1/4" x 1" x 1" (I guess) tee just inside the basement wall and run one side of the tee through the existing TV and to my Dad's boiler about 10 feet away (ultimately to a plate exchanger that I suppose I would have heat up the water being returned into the bottom of my dad's boiler) and the other side of the tee will go across my dad's basement and over to the workshop (~100 feet) where it will go into it's own TV before going into some type of heat exchanger over there.  I should not rely on the circulator pump at the boiler to drive both of the loops, but it will continue to drive the side of the tee that goes to my Dad's furnace?  I would put another pump (running continuously) on the other side of the tee in the loop that is going over to the shop.  Disregarding the Taco 009 that I already have, could you tell me what brand/size pump you would put at the OWB (or would you move it into the basement away from the OWB?) and what brand/size pump you would put on the loop going over to the workshop (and where would you locate that pump?)?  Thanks again!

That is correct. Basically you'd cut a tee into each existing 1-1/4" line (one in the supply and one in the return) right as they enter the house, or at least on the OWB side of the existing TV. The circ at the OWB will not push water that distance through the 1" branches of the tees, so you will need to add a secondary pump on the supply line of the workshop loop, ideally right after the tee, and push it through another TV that only exists for the workshop loop. If it were my job, I would install a Grundfos 26-99FC at the boiler for the main loop and a Grundfos 15-58FC on the workshop loop. Bell and Gossett NRF-36 at the boiler and NRF-25 on the workshop loop would be my second choices as I'm biased against Taco's reliability. Seeing as you already have the 009 bought, you would be able to reuse that on the workshop loop if you choose and only buy one for the boiler loop, leave it out at the boiler not in the basement. A Taco 0010,0011,0013,0014, or 2400-WB would all fit the bill also if you are wanting to stay green. Personal preference, but I've seen enough of those green ones fail on OWB systems that I'll never buy another one. Another thing is the ability to change speeds. Your 009 and most of the 00teen pumps are all single speed. At the boiler this isn't necessarily a bad thing, but your secondary loop to the workshop can benefit from having a lower speed. The 009 is not a high GPM pump anyway, so I think it will be just fine in there. Just be sure to put a balancing valve somewhere on the discharge of that pump to help balance flow if need be- the valve of an isolation flange works well, or a simple ball valve on the return line off the branch of the tee works well also. This valve can also double as a shutoff if you need to kill flow to the workshop for some reason
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