Outdoor Wood Furnace Info
All-Purpose OWF Discussions => Plumbing => Topic started by: mlappin on November 24, 2014, 10:07:32 PM
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Started pricing out what it will cost to replace the pex in the basement with copper, where should a dielectric union be used? Since the plate exchangers are stainless a regular union should work shouldn't it? I'm looking at needing at a minimum 10 of em not all one inch though. Adding a plate exchanger for DWH and going to replumb the one I already have for the snow melt system, then another two at the HX in the furnace. Of course at the moment I haven't shopped around too much yet.
@Slim, already have the long radius elbows on order.
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I use normal unions on all but domestic water, You'll like the long radius 90's!
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Last thing, type M or type L for the lines.
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Dielectric unions only really needed to be used between non compatible metals but I like to use them instead of regular unions when possible even when not needed. Partly because they cost 1/3 as much as a copper union and I prefer the rubber gasket.
Just curious, why are you replacing the pex?
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M for heat, L for domestic water.
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Dielectric unions only really needed to be used between non compatible metals but I like to use them instead of regular unions when possible even when not needed. Partly because they cost 1/3 as much as a copper union and I prefer the rubber gasket.
Just curious, why are you replacing the pex?
The pex ran in the basement for the boiler system isn't true one inch, since I have the Logstor now I see no point in having the extra flow with it just to restrict it down with the smaller line in the basement. Copper is just easier to keep a neater looking system as well.
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GREEEEAAAT Choice!!!!!
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It does look better but unless you had a lot of pex, it will probably only give you a very slight increase in flow. Assuming the underground pipe was fairly long, that is where most of the increased flow will come from.
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I think the majority of the restriction is with the pex 90's, measure the inside diameter and then think about what I have said in layman's terms about the truck coming to a Stop sign or on ramp, at the very least, with copper we can elect to use the long radius refrigeration 90's to reduce restriction
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Yes, pex 90's are the worst. They aren't that bad though if only a few are used. They are equivalent to 10' of straight pex.
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Thing is I need the flow, especially when the snow melt system is in use. I'll grab a measurement in the morning but what passes as 1" standard pex looks about the same as what a 3/4" steel pipe cross section would look like. I can also use the radiant heat off the copper as the basement has always been a bit chilly.
I'm using a grand total of zero pex 90's atm.
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How many feet of 1" pex do you have and how many 90's will be in the new copper? If you compare the outside diameter of the pex to the copper, you will see that it is the exact same size. That is where they get the size for pex.
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Well from specs type M copper will be slightly bigger than 1" ID, something like 1.055, the pex ran thru the basement now has an ID of .865 according to my slide caliper.
Doesn't sound like a big difference but when using the circulator chart from Taco that .135 makes a big difference even though there is roughly only seventy feet of that smaller pex in the basement. Once I get the new wood boiler built I'm sure I'll be upgrading pumps and want enough flow to stay as close as possible to that magical 20 degree delta T even with a call for heat, hot water and melting snow at the same time.
I ran into the same thing in the shop, either buy expensive circulators and use 1" pex or goto 1 1/4"pex and smaller circulators, was more cost efficient given the relatively small difference in price of the pex to go with 1 1/4".
I'll have at most 12 long radius 90's in the basement. I'm sure Tacos chart is assuming 90's are the standard short radius like used in domestic plumbing. If the radius is long enough on them shouldn't be anymore restriction that a straight piece of pipe.
Kinda funny though, will be changing pex out for copper in the heating system and then later redoing all the domestic plumbing with pex. Have a real mishmash of stuff in the basement now. Have CPVC, galvanized and a few pieces of what I'm sure is leaded pipe yet. Just going to start all over from where the well enters on.
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How many feet of Logstor do you have?
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117 feet to the house.
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M for heat, L for domestic water.
your reversed on this. My research, Copper M is for general residential use. domestic water, in the wall, etc. It is thinner. Copper L is for commercial and hot water systems. It is thicker. This is probably the better choice for our systems.
Incidentally Copper L is also used to plumb air compressors in automotive shops as well. There is special stress solder that is recommended to thwart cracks in solder from vibrations of the compressor.