Disadvantages to oversizing in-floor tubing?

PeterGriffin

My concrete guy is insisting the use of 3/4" pex tubing because "every effin commercial building is done with it." Sounds more like he either stole it or had lots left over from another job, I don't really care, just want to make sure the system will work with it.





Thanks in advance

The Steam Whisperer (Formerly Boilerpro)

Yes....

First off is cost, second is that water could move so slowly through the tubing that it will be very difficult to get air to purge out of the system.  There are mimium water velocities recommended due to this problem.  I have used 5/8 because of the enormous length of a building, but never 3/4.

Bob Bona_4

it would

be an absolute BEAR to wrestle 3/4 to manifolds, and the increased cost of the manifolds and fittings to boot. Plus, all the other things BP mentions.

HDE_2

More to it?

You wont suffer with larger tube unless you must pay more for the tube and accessories.

The downfall would be if he wants to increase spacing because of increased output capabilities but would suffer on comfort.

hot_rod

long loops with 3/4

on large shops where you don't want a bunch of manifold locations 3/4 works well. 500- 600 foot lengths are possible, so you can run out 300 feet an back.



On large diameter tube the PAP or Viega FostaPex tends to stay put better. Regular 3/4 pex works in hot sun



Be careful with PAP over rebar or wire as it can kink easily, especially if the rebar or wire is lifted on chairs. The Viega Fosta Pex is the best tube to eliminate that worry.



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