tubing spacing

greenhead_2

I am bidding a 4000 sq ft shop I always like putting 1/2 tubing at 12" centers he is getting cheaper bids at 3/4 at 18" centers is there any draw backs doing it that way. like ( stripping and no oops factor ) ect ?

Gordy

For a shop not so much concern for striping so long as the tube spacing, and water temps can handle the heat load of the building. What kind of shop? Will there be equipment contributing sensible loads?

But I would do 1/2" at 12" just for the sake of lower water temps, especially if the boiler will be a high efficiency. More material, but a better over all job in my opinion. Sorry to say that will be the competitions edge. YOU need to market your method to the client. Explain the pluses even though your costs are higher. Sometimes they will spring for the higher bid if it makes economic sense.

Ironman

Has a load calc been done and proper radiant calcs to determine what spacing and size is needed?

Using larger tubing doesn't drastically increase the output; tighter spacing does. Larger only allows longer runs due to less head per foot. 18" spacing is beyond what my radiant calculator recommends. It may work if you have a low btu per sq. foot load, but I wouldn't go that way.

Someone needs to do the proper calculations and show the customer what is required, not what they THINK will work.

What's the use in spending money for something that doesn't function correctly even though it may have been cheaper?

The laws of physics will out-weigh the laws of economics - every time.

greenhead_2

its a shop for farm equipment, with sensitive equipment in there

SWEI

Sensitive equipment is not going to care about a few degrees of heat striping, but there are other ways to cut costs.

If this is a large area, you might look into the embedded header designs using Aquatherm with PEX.

hot_rod

a few advantages of the larger 3/4 loops, longer lengths mean fewer manifold ports and fewer manifold locations.

You cover a lot of square footage with long loops and wide spacing, just be sure you can cover the load.

18" works out well on the 6X6 wire mesh also.

in the large shops I installer, I ran 600 foot loops at 18" as per the load calc and designs from Watts Radiant.

Large shops are ideal for mini tube injection systems. A couple small diameter, high temperature S&R and VS injection mix at the manifold.

ProblemSolver

Call the manufacture; they'll want there stuff to work, so they would help or give you a local distributor who will help. Let them say what will work and not work, they know there product.

ProblemSolver

Their stuff / their product - sorry about the spelling.

Gordy

It all starts with the load calc.