radiant heat question

[Deleted User]

12 divided by 10 = 1.2 This gives you the linear footage per square foot factor for the tube at 10" O.C.

1.2 plus .15 (to compensate for return bends etc) = 1.35 linear feet per square foot of surface area. Hence, 1.35 x 2000 = 2,700 feet of tubing. This assumes that 100% of the tubing is in the slab, and not a lot wasted in "leader" length between the manifold and the snowmlet area.

I like to keep my loops around 250 foot in length whenever possible. Less waste out of a 1000' roll. So, continuing with the math, 2,700 divided by 250 foot circuit lengths (or whatever number you chose to use) = 10.8 circuits, rounded up to 11. Thence, 2700 divided by 11 = 11 circuits of 245 foot long circuits.

Now, you wanna talk flow so you know how big the supply and return mains should be??? Or has the engineer already calculated that for you.

Good Luck!

ME

joe_65

radiant heat/snowmelt ?

I am installing snowmelt in a large walkway and sidewalk about 2000 square feet. How do i figure how much tubeing it will take to cover the area if i am running 5/8" tube 10" on center. Also is a 300 foot loop to long for a snowmelt system should i run shorter loops?

kevin coppinger_4

Do you have....

a heatloss? It would answer that question? It would also tell you how large a boiler and what you need for a pump....kpc

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

joe_65

don't have a heatloss the boiler has already been sized and the supply temp has been figured. The engineer is being no help in how the tubeing should be layed out he suggests that we run 190' foot runs. and would like to see 10" centers but as far as how many loops we use or how we lay them out he is being no help

hr

Spacing coefficients

6" oc 2.10
8" oc 1.58
9" oc 1.40
15" oc .84

Multiply the square footage by these numbers to get real close to required footage needed. then as Mark indicated break into loop lengths.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

You need to know total flow required, then figure flow per loop as well. That will tell you the loop length limitations you have as you can figure head loss for that flow with the glycol mixture you are using. 300' is usually too long in snowmelt for 5/8" pipe.

Also don't forget to use counterflow patterns for the tubing layout!