# Radient floor heating I need information



## Jim Bunton (Mar 16, 2004)

I am looking to put up a 56' x 32' x 12' pole building next summer. It will have a 6" concrete slab floor with 2â foundation approved insulation board (R-10) 6mil vapor barrier. Walls will be 12" high and have R 19 insulation ceiling will have R30 insulation. I used a chart that I about half understood and it looked like I would need a boiler in the 18,000 BTU range to maintain a comfortable temperature 70degrees during an Illinois winter. This seems low to me. Any opinion out there or is more info required?

Thanks Jim

















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## TnAndy (Sep 15, 2005)

Sounds way low to me.

Call these guys.....they are very good on radiant floor heating.

http://www.radiantcompany.com/


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## werb2008 (Feb 5, 2015)

I think your missing a zero off the btu rating!


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## wy_white_wolf (Oct 14, 2004)

Well those 12 inch high walls don't make for a lot of volume to be heating! :facepalm:

Sorry I just couldn't resist.

Everthing I looked at for calculators put it in the 50K to 70K BTU range.

WWW


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## Maura (Jun 6, 2004)

With in-floor you may need a hot water heater rather than a boiler. Yes, you can use a boiler, but you may not need to because you would be using warm water rather than hot water.


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## spacecase0 (Jul 12, 2012)

the max concrete slab temp you want is about 90F, so a boiler might no be ideal 
solar hot water works well for the floor heating systems, 
or at least where I live it does 
and it takes 3 days to cool off the concrete floor, so the days without sun should not hurt to much 
the building I live in has had a broken floor heat system for about 4 years, (I am not allowed to fix it) 
and the solar is way better than nothing 
past that just use space heaters and you will likely save a huge amount of fuel or electricity


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## mreynolds (Jan 1, 2015)

I have a question to ask all those from up north myself. I have been a builder all my life in the south and we have high ceilings because the heat rises and it stays cooler in the summer. It also stays cooler in the winter but its usually no big deal for us. I did build for a bit up around Bethlehem Pa and the ceilings there were usually 8'or 9'. 

What is the advantage to having 12' ceilings in a cold climate? Is there something I am missing? 

that being said, I would most assuredly use open or closed cell foam for insulation. I built a 12' pole barn last summer for my boss and it was only insulated on the roof with open cell foam. (for keeping the heat down in the summer only) It had no heat or cooling in it as it is for storage only. Last December it got down to 25 one night and inside it was 55 degrees at 8 in the morning.


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## werb2008 (Feb 5, 2015)

See if this link works its for the system your looking for and they will help you design it for the do it your selfer.
http://www.radiantec.com/store/store.php?catID=6


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## Mallow (Aug 4, 2006)

TnAndy said:


> Sounds way low to me.
> 
> Call these guys.....they are very good on radiant floor heating.
> 
> http://www.radiantcompany.com/


I used this company a few times. They are easy to deal with and knowledgeable.


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## beenaround (Mar 2, 2015)

werb2008 said:


> I think your missing a zero off the btu rating!


Maybe not, if the building has no openings at all it might be close. 

Exterior walls and there openings are a big part of determining heat lose.

Pole barns are not designed to be efficiently temp controlled. A lot of care needs to be done to stop the transmission of the outside temps, metal being one of the worst or best at rapidly transmitting outside to inside and the other way round, concrete is right up there.

Heat lose calculation are set to their max at certain temps, you need to adjust if the area isn't within those parameters. I think the set range is 10 degrees outside and 70 inside. If temps go below that the system won't be able to maintain 70 degrees inside. 

My home is set at -10 outside and 70 inside with a central wood burning boiler. It is not over sized doing over 3000 sq.ft. with an output of just over 80,000 btu's set normally, but the great thing about water is the btu output is adjustable by simply increasing or decreasing the water temp. However, as pointed out radiant in floor heat has it's limits on how hot it can get and you still being able to walk bare footed. Some do not understand the need to drop the temp in floor and operate it at the 180 a boiler normally is set at and let me tell you, when it's going you can't stand in one place long with bare feet.

You can get by with a hot water tank, maybe, most are at least 36,000 btu's as long as the heat lose is seriously addressed. If not, zoning the system with the ability to add another hot water tank would be a smart move. I wouldn't rely on the foam board to be the break between outside and in. Something much greater is needed and loading up the tubing near the exterior advisable.

To give an idea of a super efficient wall, it would be made up of double 2x4 walls with the studs offset from each other, you'd have a 2x8 wall made up of 2x4's with 2x8 top and bottom plates.. The insulation in the inside wall would stop the transference of the outside studs and the outside the inside. Pole barns are big losers trying to apply this. As another example take a piece of metal (thin). Open a window, stick half outside and half inside, close the window, see what happens to that metal. It's why metal windows once sold as lifetime are no more in residential construction.

Long time ago I was part of a similar pole barn project, a home meant for Texas was built here in Northern Ohio. I was just hired help, but I can still see clearly why in the end this home would freeze a person to death. The solution was to add another heating system on top of the large one it already had which I heard later had happened. Today's heating/cooling costs would be unbelievable. The owner was the head of Hospice.

!8,000 for an answer means you are way off.


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