# Insulating Pex



## fourustircom (Feb 18, 2008)

Hi, Folks!

Instead of buying Microflex or other pre insulated Pex, has anyone tried insulating the Pex and placing in corrigated drain pipe themselves? What kind of insulation did you use?

The stuff I think my dealer wants to sell me looks like PVC wrapped with foam. It appears that both the Pex lines are run through the PVC which means the 2 lines are touching. I understand that is a bad thing. Or is this not the plan.

Thanks!


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## HUSKYMAN (Feb 18, 2008)

The two lines touching is not a problem. You have to be careful with the PVC stuff because it does not bend so you have to use and purchase elbows for every turn which makes installation a much bigger PIA and makes pushing the pex lines through more difficult

I prefer the pex line already insulated and inside a 4 or 5 inch tile. It comes in big rolls and installs much faster. It also costs about half as much and works very well.


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## Husky137 (Feb 18, 2008)

In my thermpopex, the 2 lines are insulated from each other, no touching.


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## iCreek (Feb 18, 2008)

*PEX insulation*



fourustircom said:


> Hi, Folks!
> 
> Instead of buying Microflex or other pre insulated Pex, has anyone tried insulating the Pex and placing in corrigated drain pipe themselves? What kind of insulation did you use?
> 
> Thanks!



I have seen the pre-insulated PEX, looks nice but was way out of my budget. We used 4" schedule 40 pipe buried below frost line to the stove, $1.40 a foot, and insulated the PEX inside that pipe with some 5/8" pipe insulation I got at Lowes, $2.00 per 6' section. I think it would depend on your location and climate, we are in the midwest and our frost line here is shallow 30" - 32". 

Here is a past post on my project.

http://www.arboristsite.com/showthread.php?p=826913#post826913

Here is a look at my inside run to my utility room, on an inside wall, using the insulation, the blue line is cold water going out to stove for filling.








I am sure we have some heat loss, more than if I spent $ 11-17 a foot for the better insulated pipe, but when the snow and ice was on the ground I could not see the pipe path to the stove. I bought my PEX for .45 a foot at Lowes also, so my install was kind of 'do it yourself'. 

Here is a pic after about 5 minutes running, I still need to insulate all the way to the exchanger. I have gotten 170 before, just got to IR the right spot.






The below pic is what I am getting out of my heat registers, I guess this is alright, seems to heat our house pretty quick.


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## HUSKYMAN (Feb 18, 2008)

I didnt bother insulating all the way to the exchanger, as long as the pipe is in the house the heat is not being wasted. 

Also there is no net heat loss by not insulating each pipe in the PVC. So what if the temp at the heat exchanger is a few degrees less, the water will be hotter when it gets back to the boiler so the heat is not wasted. Seems like extra work with no benefit to me.


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## iCreek (Feb 18, 2008)

HUSKYMAN said:


> I didnt bother insulating all the way to the exchanger, as long as the pipe is in the house the heat is not being wasted.
> 
> Also there is no net heat loss by not insulating each pipe in the PVC. So what if the temp at the heat exchanger is a few degrees less, the water will be hotter when it gets back to the boiler so the heat is not wasted. Seems like extra work with no benefit to me.



Hmmm, OK, maybe I don't need to insulate all the way to the utility room  I was thinking out loud I should, but my basement is heated and I don't appear to have a problem heating the house the way it is.... I could save a few bucks, thanks for the tip, learning here everyday

Does anyone else here have some temps at exchanger and at registers?


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## Geez (Feb 18, 2008)

I installed my OWB last fall but never insulated the pex for the 35 feet (each way) from the foundation where it comes in to the heat exchanger. My crawl space and cellar are not heated except for residual heat from the house and off the furnace, so I figured the heat would not go to waste.
Anyway, a couple weeks ago I finally got around to insulating the lines and my inline thermometers jumped 6 degrees at the exchanger. I don't really notice any drop in air temp in the cellar either.
Under the circumstances, I wish I had done it earlier. Who knows how much less wood I would have used.:bang:


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## iCreek (Feb 18, 2008)

Geez said:


> Anyway, a couple weeks ago I finally got around to insulating the lines and my inline thermometers jumped 6 degrees at the exchanger. I don't really notice any drop in air temp in the cellar either.



What was that temp reading, at your exchanger? Just curious.


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## fourustircom (Feb 18, 2008)

*Insulation?*

So, Geez, what did you use/do to insulate and surround your PEX? I read somewhere that one should add sawdust(?)over the pipe before filling in the trench.

Lot's of great info!

Thanks!


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## fourustircom (Feb 18, 2008)

*Thermal expansion*

Maybe this is why PEX should be loose fitting in the conduit of choice...

PEX will install a bit differently than normal PVC or copper tubing. Allowances must be made for ever 10 degrees of change in temperature. PEX will contract one inch every 100 feet of pipe with every 10° of temperature change. Offset this by making a loop in the PEX that is no more than 8 times the diameter of the tubing.

This was from a DIY site. Maybe that foam filled, corragated, Pex pipe is not such a "hot" idea!


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## MS-310 (Feb 18, 2008)

The key to a good underground pex line is....To keep it dry. I mean that it has to be in a sealed tile, wraps dont work (tear easy). Microflex is alsome stuff used it for 3 or 4 years now and love it, it can really flex comepared to logstar and other types....Remember closed cell foam and keeping the water away from the pex lines....Also sawdust holds water. We sell it and other types also.


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## crowbuster (Feb 18, 2008)

I thought the same as you icreek, leaving the heat in the basement, had to insulate after all, it was way to hot in kitchen and loading room. Utility room was also way to hot. Much better after I put the foam pipe wrap around the lines and exchanger, has to save on wood as well.:greenchainsaw:


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## abohac (Feb 18, 2008)

*Pex*

I agree MS310. Before I put mine in I asked tons of questions and the best advice I got was keep it dry. I thought the cost for that premanufactured stuff was way to high but then again it is the most important aspect of your stove. You simply have to have this part right or things just won't work right. I don't know who told you that the lines shouldn't touch but I have 4 1" lines in the PVC you are talking about (they are jammed in there and it was a real #####). I went with some stuff made in Canada that was over a $1 per foot. It was foam over PVC wrapped in a rubber sleeve. I glued it then the manufacturer gave me what resembled rubber bandaids for each seam. I dug my trench on grade with fall to the house so that the water could get out of the pipe if I ever srpung a leak. If I were you I wouldn't skimp on this portion of you installation.


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## ericjeeper (Feb 18, 2008)

*I will give my feelings.*

I am trying to heat the house. Not the boiler. So I insulated each line individually. I slid armorflex over the pipe.(is a lot like trying to put socks on a rooster)
paired the two insulated lines up then took the foil faced bubble wrap insulation used the 16 inch wide roll then paired the two lines together in this. Then I wrapped it all in shrink wrap.. Lots of roundie rounds.Then I shoved it into a 5 inch non perforated corrugated tile..My run is only 40 feet or so and I had to be above the slab on the house end and just below grade on my storage tank end. So no need to bury it below frost.It is no deeper than one foot. Where my lineset entered my storage tank I Peeled back shrinkwrap and insulation and filled the pipe with that expanding spray foam. (you know the stuff that sticks to everything within a mile of where you squirted it) As I do not want steam to go into the lineset from the storage tank. The other end enters the sidewall of my garage well above grade.. The ground freezes tight over my lineset so I figure I have done my job in preventing heat loss to the earth.


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## Geez (Feb 18, 2008)

iCreek said:


> What was that temp reading, at your exchanger? Just curious.



After insulating, I'm running at 162°


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## Geez (Feb 18, 2008)

fourustircom said:


> So, Geez, what did you use/do to insulate and surround your PEX? I read somewhere that one should add sawdust(?)over the pipe before filling in the trench.
> 
> Lot's of great info!
> 
> Thanks!



In the crawl space and cellar I used the foam pipe insulation you find in most hardware stores. The buried lines are the pex wrapped with closed cell foam in drainage pipe. They are buried about 4' deep and I covered them with 3" of foam sheathing insulation about 18" wide before burying, with strips alongside the pipe as well.
I didn't use the high tech piping but it's working well. At leat there is no sign of snow melt or winter grass growing over them.


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## fourustircom (Feb 19, 2008)

*Insulating*

I had not planned on scrimping/cutting corners on that part, but if I can get the same result and save a buck, I could but that to better use elsewhere. Cool ideas! 

I've heard the thing about tubing not touching from several places, here and elswhere. I'm not sure of the reasoning, folks preheat the water coming into a waterheater. It seems like the same kind of thing.

I think having the underground and inside tubing well insulated and having the furnace in the wood shed out of the wind should help reduce heat loss and hopefully the amount of wood I'll be burning.

Thanks!


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## tanker (Feb 19, 2008)

I spent the money and used the good stuff(logstor) 2-1'' lines in polyurethane then a foil wrap then what looks like about a 5'' waterline. Temp of 195 at boiler 160' from house,temp of 195 at basement. I guess I don't understand the extra waterline out to the boiler that I see most people put in,on my waterheater sidearm,2 water spigots,1 on the cold fill on the water heater,1 on thehot in from the boiler. A washing machine hose( hose with 2 female ends is all you need to fill the boiler. This is my 3rd year with my boiler(35% no-burst boiler antifreeze mix) and I have not had to add any water, the level is the same now as when I first fired it up and the nitrite level is still good and haven't had to add any extra chemicals


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## Geez (Feb 20, 2008)

tanker said:


> . I guess I don't understand the extra waterline out to the boiler that I see most people put in,on my waterheater sidearm,2 water spigots,1 on the cold fill on the water heater,1 on thehot in from the boiler. A washing machine hose( hose with 2 female ends is all you need to fill the boiler.



This is the method I use as well. The downside you must be aware of though, is the potential for boiler water and chemicals possibly backflowing under certain conditions into your water source (well) and contaminating it. At the least you should have a check valve or backflow preventer.


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## tanker (Feb 20, 2008)

Geez said:


> This is the method I use as well. The downside you must be aware of though, is the potential for boiler water and chemicals possibly backflowing under certain conditions into your water source (well) and contaminating it. At the least you should have a check valve or backflow preventer.



actualy have 1 in the line that feeds the original boiler in the basement along with a ball valve(has been shut off since o.b. went on line) When using hose to fill o.b., with hose,just make sure what valve you turn off and on first.


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## fourustircom (Feb 20, 2008)

*Extra lines?*

I noticed in the installation manual for the Woodmaster that there are 4 valves and a drain. 2 supply and 2 return, so one set must be for an out building. I had hoped to heat an attached garage some day, so I wonder if those extra connections should be plumbed and run through during the initial installation. Looks like I would have to go larger on the drain pipe, maybe a 6" instead.

Anybody done this?

Thanks!


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## MS-310 (Feb 20, 2008)

Hay fourustircom If your not to far away from charlottle MI come on over and I'll show you some good stuff and some OK stuff. I have some microflex here at the shop....


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## MS-310 (Feb 20, 2008)

fourustircom said:


> I noticed in the installation manual for the Woodmaster that there are 4 valves and a drain. 2 supply and 2 return, so one set must be for an out building. I had hoped to heat an attached garage some day, so I wonder if those extra connections should be plumbed and run through during the initial installation. Looks like I would have to go larger on the drain pipe, maybe a 6" instead.
> 
> Anybody done this?
> 
> Thanks!



What size is the house and the size of the garage? Most of the time 1 hot and 1 return is all you will need for a house and attached garage. You can spend about the same about on 6" pvc then trying to wrap it and put it in the pipe as the about of a good type underground pipe, Trust me spend the money on good under ground pipe. It will pay off in time. How far are you running.


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## fourustircom (Feb 20, 2008)

*Insulation*

Thanks for the response, Jack! We're about an hour from you, west of Flint, Swartz Creek. Got pictures? I've seen most of what's available in preinsulated tubing from foam filled drain tube to wrapped PEX in a drain tube. Looks like the trick will be getting insulated PEX through a corrigated, non perforated pipe.

I talked to the dealer who we will probably buy a Woodmaster 4400 from and he has seen spray on closed cell foam applied over the drain tube for extra insulation.

What are you asking for your stuff?

Thanks!


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## fourustircom (Feb 20, 2008)

*logstor?*

So, Tanker, where does one find THIS stuff? Denmark? Cost? Flexible? Looks like the oil & gas industry use it so I'll bet it's pricy!

Thanks!


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## fourustircom (Feb 20, 2008)

*Pex @ Menards*

The Woodmaster dealer told me about an ad he saw for 1" PEX at Menards. 150' for $100. Best I can do in my area is $1.47/ft. His was $1.20/ft.


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## HUSKYMAN (Feb 20, 2008)

fourustircom if you are interested in seeing a 4400 Woodmaster in action you are welcome to come up to my place and see mine, I am about a half hour from you. 

I used both loops on my 4400, one to my house and the other to my pole barn. The downside to using both is you need another pump. The upside is much warmer water going to the second building. It all depends on how your boiler is set up, how far the runs are, etc.


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## fourustircom (Feb 20, 2008)

*Location?*

Thanks for the offer, Huskyman. What direction are you from me? I have to be in Warren, near Detroit, tomorrow PM. Maybe on the way home?

Directions?

Thanks!


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## beerman6 (Feb 20, 2008)

He's west of you just south of Lansing...I think.


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## MS-310 (Feb 20, 2008)

I sell microflex for 11 a foot but if you come buy it, it will be 10.50 foot....I would say I havent seen a better underground line. 

1 pex can be bought a menads for less then a buck a foot, we sell it for 1.10foot. WoodMasters are a good stove. I dont have any pics online, no way to do it at the shop but you can always give me a shout at the shop, 517-543-1116, mite have to leave a message but i'll call you back. Logstar is very hard to move around anything. trust me I have put it in and its a great product but polyurathane does lose its insulating facter after time.


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## HUSKYMAN (Feb 20, 2008)

fourustircom said:


> Thanks for the offer, Huskyman. What direction are you from me? I have to be in Warren, near Detroit, tomorrow PM. Maybe on the way home?
> 
> Directions?
> 
> Thanks!



I am north of you, between Flint and Saginaw


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## fourustircom (Feb 20, 2008)

*Logstar*

So, what kind of insulation does Logstar use? I know if something like foam crack filler is used it will absorb moisture since it's open cell foam. The your "R" factor goes out the window.


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## beerman6 (Feb 20, 2008)

beerman6 said:


> He's west of you just south of Lansing...I think.



oops,I thought you were askin MS-310


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## MS-310 (Feb 20, 2008)

fourustircom said:


> So, what kind of insulation does Logstar use? I know if something like foam crack filler is used it will absorb moisture since it's open cell foam. The your "R" factor goes out the window.



"spray foam type" also it doesnt move worth a darn.


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## tanker (Feb 20, 2008)

fourustircom said:


> So, Tanker, where does one find THIS stuff? Denmark? Cost? Flexible? Looks like the oil & gas industry use it so I'll bet it's pricy!
> 
> Thanks!



purchased from the c.b. dealer that I bought my boiler from in Greenville Ohio.He has it in bulk and will sell you however much you need. Logstor will bend a 32'' radius. I would recomend it to anyone for its ability to prevent heat loss. I think that I gave $11.00ft when I bought mine.Its kind of like buying the boiler,spend the money 1 time,do it right and then you will be happy with it Figure what you are going to spend on separate waterlines,solid tile, insulation and fittings,I bet you will be closer to the price of good pipe than you thought


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