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[netwerx-r-us]

so I've been back and forth about whether to run 1 or  2 lines for my house garage combo and another 1 or 2 lines for my greenhouse , bird building combo ,  basically I asked in an  earlier post  if i need to run one or 2 lines for my house with plate , and heat exchanger for furnace  and another for  garage with heat exchanger  or run all off 1  ,  and 1 or 2 lines for my greenhouse and another building that are 30 ft or so part or all off of 1 line set

got some very good advice from all here,

so when I say lines above I'm assuming each line has 1 feed and one return line of pex in it  but another thought has creeped into my devious little mind , what if one were to break all the rules and run 2 pex pipes for the feed from the boiler to the devices and Then combine the returns  into one line , maybe a litttle bigger for the return effectively have a 3 line in each line ?? 2 feeds , 1 return

[willieG]

1 inch pex is rated for a max of 7.5 gpm if you ran 2 of these lines you would need to run a 1.500 inch pex return to accomodate the return (1.500 pex can take 15.6 gpm max suggested flow)

i am unsure of the cost of doing what you propose but i would think that once you know the gpm flow you need you can work the math and come  up with the size of pipe you need toget water to the home..then you could used a header system of smaller pipes to feed all your appliances. (this may or may not require 1 or more smaller pumps in the house)

i run 4 "appliances" in my home with just the pump that delivers water from teh OWB.

[Scott7m]

This made my head hurt..... 

What exactly are you trying to accomplish?  I'm lost

What benefits do you seek?  Reasons for that?  I'm digging here trying to understand

[netwerx-r-us]

I probably didn't explain the end goal very well,
so lets take one run  to my house , call it run 1 , 150 or so ft , going to a 20 plate 4x12  exchanger for hot water ,  then a 22x24 water to air exchanger in my duct work , id then like to come back out and hit my garage 25 feet away where ill have another large water to air heat exchanger, chances are the garage isn't going to be used a lot at all but id still like to be able to knock the chill off and heat if need be

Run 2 about 200 ft , more importantly to a greenhouse 30 x 50  with 22x24 water to air exchanger with thermostat , then I have another bldg 20 x50  30 -40 ft away that will be well insulated for my cage birds , was looking at another large water to air for that , these cannot freeze

my concern on either is on run 1 by the time it hits the garage there wouldn't be much heat left if I ran it in a series but maybe if i split it it ,

Run 2 is the important 1 if i run it in a series I'm afraid the greenhouse will take most of the heat and leave little for the birds but if i split it 

so at the same time id like to keep costs down if i have to run 2 lines to each so be it but if it can be done with one much better ,

basically I'm trying to get the design right the first time and consider all the contigencies and achieve my goals, its a design in flight , building the airplane in the air so to speak so I'm  looking at all possibilities and considering options , id like to do that now instead of hearing later , "you should have done this "   ,

Its not that different that what I do for a living , just different hardware , so you look at your goals , find the best way to achieve them with out breaking the bank and oh yeah , its got to work , be available , redundant and be able to recover from a disaster

it may be that Im  underestimating the capabilities of these , but as Im investing a pretty good chunk of change I dont want to find out later i could have done it differently

thanks all for looking and responding , awesome site and people

[Scott7m]

Ok....  I'll be honest with you and you can take my advice if you want.  I do this for a living and know what's getting ready to happen.

You are on the verge of sending your boiler to an early death.  Your return water temps would be so low that it would cause condensation to build up inside the firebox and run down into the ashes and send your unit to an early grave.  Let me explain....  Any boiler going back a hundred years has a primary and secondary loop, that whole reason is to keep boiler water from coming back below 140.  When your burning wood, you are releasing moisture, the moisture has to be carried out the stack, moisture will not gather on steel that's over 140.  If you had 100 pounds of wood in your stove at 25% moisture, that's 25 pounds of water inside the firebox.

Now, I know your going to say but I'll just keep my stove higher than that, but what happens is where the returns come back and make contact with the firebox wall it creates cool spots for moisture to gather, run down the walls and into the ashes.  Central boiler and empyre now require boiler protection systems like all other boilers, the rest of the Industry hasn't went that way yet.

Further explained, delta t.  Let's say I install your unit, I know by pipe size, flow, coil size etc, that I can make sure your water is coming back well above 140.  The thing is though, once I leave you may add a building, add on additional rooms to your home, then all of my calculations are gone out the window.  You may very well still heating those spaces, but might be damaging your boiler at the same time.


Can it be done correctly?  Yea, it will cost a bit more but will be cheaper in the long run.  Using a close T system and having a pump for each water to air exchanger eliminates killing your flow.  For example if your garage called for heat, it would also trigger the pump to come on and put heat into the coil, once satisfied, the water would go back to bypassing the coil and keeping your flow up.  So you'd need a really good pump as your main one, and then some really small pumps for your close T set ups.   This would help to eliminate your water always coming back to low, it still might at times, but it is a definite step in the right direction.  It wouldn't be all that hard to do either, and wouldn't be a budget killer. 

You've gotta keep the flow up, keep the water running fast and so on, please feel free to ask more questions

[willieG]

 loop 1...underground insulated pipes are expensive so my idea (maybe not the best) is to go 1.25 insulated pex from the boiler to the home to a header sytem. (now this is a decision for you to make) if you are not going to heat your garage full time you might consider making the garage a loop of its own with antifreeze in it?

off the header you would feed to your exchanger in the plenum and a line to your hot water heater exchanger and another line to another water towater exchanger for the garage. you would have valves on all lines so you could adjust flow as you need. all these lines could be 3/4

now your garage would need an expansion tank and this loop would hook to the 3rd exchanger and have its own pump. OWB water would be circulating 24/7 through (likely both your hot water exchanger and your garage exchanger) now when you want to heat your garage you turn up the thermomstat and that turns on your blower and your pump. (at 50 feet from the home to the garage you could likley get by with 3/4 insulated pex here (an average of 6 gpm would deliver between 50 and 60 thousand btu per hour)

as for loop 2 you really need to know how many btu you would need for the green house. (the bird house that you say is well insulated is likely around 25 to 30 btu per square foot per hour (25 to 30 thousand) once you know how many btu you need for the green house you can then make a plan

[Scott7m]

A header system could work as well, why not just have a header system and let individual small pumps kick on as heat is needed, it works great and with the pumps available today, I'm not that concerned about them going out.  Especially when they'd only run a little each day

[RSI]

You are better off using one larger pipe than two smaller pumps. I don't have time right now to read through your setup real good but I would probably run either 1-1/4" or 1-1/2" pex to the building and then run 1" to each heat exchanger. See this chart to get an idea how much different the pipe size makes. (almost cuts the pressure drop in half each size you go up.
http://www.alliedpex.com/LITERATURES/PEX_Pressure_Drop_Table.pdf

[netwerx-r-us]

all good advice , I think that since every install is a bit different I will run my   line to house and hook up the plate exchanger and water to air exchanger and monitor what the temp is at various stages  of the process , at OWB , at plate , at air exchanger and back at owb and then make a decision then if the garage can be added without dropping to much ( good advice scott )  , if i need another line the ditch will  still be open same goes for my greenhouse /bird building ,  after all i have 4 ports on my OWB and already have 3 pumps

I saw on another site RSI and another guy had a fancy web monitoring system , I'm going to have to look into that

thanks  all

[RSI]

Here is mine http://www.my-thermometer.com/

[netwerx-r-us]

details , who what where when and how ?