Pex tube and a frozen floor...

[mx842]

MacLawn........Don't let my situation sway your decision. MY install is not typical and a lot of my problems are due to not being able to afford to finish my building in a timely manor. This has been a work in progress for almost three years and trying to see all problems that may come up later on in the build is sometimes hard to do. Especially when you change plans or decide to add on or take something away from what your original Ideas were. Believe me in three years there are a ton of changes someone like me can come up with that will change the overall picture and results a year or two later.

Normally when you build something like this you have the money, come up with what you want and then have someone build it for you and you just move in. But in my world I didn't have that option and I have had to do things a little different and is more a pay as you go kind of thing. At times I have almost just given up the idea altogether and just give up on the idea of having a nice heated space to work and store all my tools and junk but somehow I have managed to keep at it and hopefully before I kick da bucket I'll finish it. At first it didn't bother me if it took awhile because of the wonderful economy we have going. I figured there wasn't much going on anyway but this knothead can't remain king forever and once he is gone maybe things will come back around and I do want to be ready when it does.

I still believe radiant heat is a great option for a building like I have and even with the problems I am seeing now I'm glad I decided to go this route. It may cost a little up front but in the end I truly believe it will be worth it.

 

[Fi-Q]

Mx842, I am with you... Don't give up, you'll get there . Build the shell of my house 5 years ago, but been livin in my basement since !!! But i am taking a few months off when this assigement is over and should be finishing most of the house this year. I guess I need to do it before my wife decide she want to find a finish house somewhere else !!

I am no radiant expert, but if you want to learn more and have some expert or DIY pros, join the forum at hearth.com , the boiler room is full of awesome boiler, radiant heat and hydronic information.

I did bought the last version of John Siegenthaler : Modern Hydronic heating, its the bible of hydronic heating. I think its around 150$ these day on amazon. I did have the time to read it as of yet.

 

[MacLawn]

mx, man your build sounds like the way I do things. No money, some skills, some time. Maybe I'll check more on this floor heat mess now. Thanks.

 

[Redneck in training]

This obviously the right thing to do in cold climates. What kind of antifreeze are you using, what is the maintenance schedule and how are you isolating it from the domestic water?

Thanks.

It is propylene glycol water mix. Propylene glycol is biodegradable and is not poisonous. If also has better lubrication properties than water so the circulation pumps last longer.

 

[davedj1]

I think there are too many backyard plumbers giving advice and speculation on what is happening. First of all, pex can freeze and thaw with NO issues. We keep a sample about 18" long, half full of water, capped at both ends and stays in the truck year round. It has frozen and thawed a time or two. That being said, the inside diameter of the in floor radiant pex should be no more than a half an inch, more likely less, so there isn't a whole lot of expanding going on. It sounds to me that the op doesn't have his system plumbed up properly, if he his having a problem getting his boiler temp above 80*. On an outside wood boiler, the underground pex can expand in length as much as 6" when brought up to operating temps.
To the OP,
Do you have a water supply hooked to the boiler to maintain pressure in the sytem? Who sized the loops? There is a specific size you shouldn't exceed. It sounds to me like you are running an open system with the blue barrel (un-insulated I assume?) Is the slab insulated under the pex? By nature, the ground is a constant 48* or so and the ground below the slab will try to maintain that temp.
The reason anti-freeze isn't advisable is that it takes more energy to heat it than it does water, by like 30% more. It does have it's place if the home is left unattended for extended lengths of time in the frigid temps. It beats having a frozen system.
I would like to see some pictures of your setup.
dave
Disclaimer, I'm not a plumber, I just have a lot of experience with pex and radiant in floor heat.

 

[DANOCHEESE]

davedj1 makes some very good points. I heat my entire ICF house with a water heater. This year I have used the cold air furnace to supplement . Loop Length will mess with your monkey.

 

[mx842]

I think there are too many backyard plumbers giving advice and speculation on what is happening. First of all, pex can freeze and thaw with NO issues. We keep a sample about 18" long, half full of water, capped at both ends and stays in the truck year round. It has frozen and thawed a time or two. That being said, the inside diameter of the in floor radiant pex should be no more than a half an inch, more likely less, so there isn't a whole lot of expanding going on. It sounds to me that the op doesn't have his system plumbed up properly, if he his having a problem getting his boiler temp above 80*. On an outside wood boiler, the underground pex can expand in length as much as 6" when brought up to operating temps.
To the OP,
Do you have a water supply hooked to the boiler to maintain pressure in the sytem? Who sized the loops? There is a specific size you shouldn't exceed. It sounds to me like you are running an open system with the blue barrel (un-insulated I assume?) Is the slab insulated under the pex? By nature, the ground is a constant 48* or so and the ground below the slab will try to maintain that temp.
The reason anti-freeze isn't advisable is that it takes more energy to heat it than it does water, by like 30% more. It does have it's place if the home is left unattended for extended lengths of time in the frigid temps. It beats having a frozen system.
I would like to see some pictures of your setup.
dave
Disclaimer, I'm not a plumber, I just have a lot of experience with pex and radiant in floor heat.

With all due respects Davedj1, backyard plumbers? Then you follow up with your disclaimer........HUH?? I'm not beating on you cause I do appreciate any feedback that people are willing to offer. And yes, sometimes on forums like this sometimes its hard to get a full grasp on what people are really putting into words. After all most of the guys and gals that post here are not writers or editors they are mostly people like you and I that have various skill levels in one line of work or another that want to learn about other things either for just increasing their knowledge or for ideas that can be put to use with a home project they want to do.

I like to learn new things but I am also a tightwad.......which I have to be at this stage in my life. I don't have the luxury of just calling up the experts to have someone else come over and do things for me so if there are things I need to get done the buck stops here with me. Sometimes I have to wait until a deal floats buy before I can act and yes doing stuff this way takes a long times to complete and a lot of times it will cost more than it would have to just go out and buy a store bought model but for people like me and many others that post on this forum there is a great deal of satisfaction that comes to you when you finally get a project done and you can look back and and actually see in action the fruits of your labor.

It wasn't the pex I was worried about it was the pex in the concrete that was the issue. Actually at the time when I posted this thread I was exhausted, almost brain dead and like any whipped pup just wanted to find a willing shoulder to cry on. At that point it didn't really matter. The floor was already frozen........... 24degrees in spots all I wanted to do was beat on myself and let the world know I had let this kind of thing happen.

So here we are. I guess it would be a good time to post for the record just what it is I am working with. I posted a long time ago when I first got this old wood stove some pictures of this monster. It's not an outdoor wood boiler what it is, is an old Waterloo wood burning stove that someone cut the top of of and placed an old boiler they had gotten from somewhere on top and tried to make a wood burning boiler out of it. Evidently they didn't have much luck with it and is the reason I am the new proud owner of this pile of scrap.

It looked cool as **** when I first saw it and was tempted to pull the $300 out of my pocket that the old owner wanted for this prize piece of ancient history but for once I listened to that little voice in the back of my head that was screaming DON'T DO IT!!! I passed on this deal of a lifetime and went home empty handed. About a week later the guy called me to inform me the price had somehow dropped to around $150.00 and I could come get it when ever I wanted to. The little voice was still yelling....DON'T DO IT!!! The following week it was just come get this thing out of my garage, I need the room. That satisfied my little inner voice but I can't help but wonder if I had waited another week what the guy would have been willing to pay me to haul it off for him.LOL

When I first got it I fired it off out in the yard and in less than 15 minutes it had heated the water in the boiler to 160 degrees so I figured it might work to heat the floor until I had a chance to build my new outside wood burning boiler that will heat my shop and my house. The rest is history before I could get my big door built and the boiler plumbed in an working we get hit with the worst winter in recent history.

I had intended on turning this stove into a gasifier but never got that far and when the cold weather hit I had to go with what I had and although it did thaw out the floor and has been keeping it above freezing so far, it is far from being fit for service. My original plan was to install a 100 gal water heater to heat the floor until I got my boiler built but never could get the money together to buy one. Right now all I'm doing is chucking firewood to this thing just trying to keep up and waiting for the weather to break. Hopefully this will help clear things up a little so you can get a better idea as to what it is I am dealing with.

Here's a link to a thread I posted when I first got the stove.

http://www.tractorbynet.com/forums/projects/283441-old-wood-boiler-boiler-guru.html

Another showing the floor layout.

http://www.tractorbynet.com/forums/build-yourself/258866-finally-after-almost-2-years.html

 

[not2old]

I've found this thread to be very informative. My shop is still in the planning stages, but I expect to install a similar heating system with auxiliary heat to the house in case my geothermal conks out. As dumb as it sounds, I'm thinking about adding some heat to an area outside the front of my garage and sidewalks too.

 

[davedj1]

MX842, I meant no disrespect to anyone including you, I was just trying to help.
I am all for getting deals, doing my own thing on a budget and getting the satisfaction of saying "I made that".
I know what you mean by interpreting things or conveying them in these forums.
I guess I missed your concern with the pex damaging the concrete. Unless the pex is extremely close to the top or bottom of the slab it shouldn't be a concern. The expansion will take the path of least resistance just like water, it would probably just expand the pipe lengthwise.

Here's some interesting reading, and yes, pex can burst.
http://www.nrel.gov/docs/fy06osti/39664.pdf

 

[mx842]

MX842, I meant no disrespect to anyone including you, I was just trying to help.
I am all for getting deals, doing my own thing on a budget and getting the satisfaction of saying "I made that".
I know what you mean by interpreting things or conveying them in these forums.
I guess I missed your concern with the pex damaging the concrete. Unless the pex is extremely close to the top or bottom of the slab it shouldn't be a concern. The expansion will take the path of least resistance just like water, it would probably just expand the pipe lengthwise.

Here's some interesting reading, and yes, pex can burst.
http://www.nrel.gov/docs/fy06osti/39664.pdf

You b cool......I didn't think you did anyway and was trying to express myself in a way that would benefit everyone that might be thinking of doing something similar. By all means express your concerns and offer up any advice you may have that can be useful. A lot of times people will, on sites like these post remarks about all the reasons you should or should not attempt a project like this, or simply point out all the stuff that is wrong but never offer up any solutions. They for all practical points and purposes just want to argue and start a pizzing match. I'm not saying that's the way you came off it's just that I guess i'm a little gun shy these days with all the problems I have come across and needed a little friendly advice. I do appreciate your input very much and thanks for the link.