Hydronic radiant system tubing shall be installed in accordance with the manufacturer's installation instructions and with the tube layout and spacing in accordance with the system design. Except for distribution mains, tube spacing and the individual loop lengths shall be installed with a variance of not more than ±10 percent from the design. The maximum loop length of continuous tubing from a supply-and-return manifold shall not exceed the lengths specified by the manufacturer or, in the absence of manufacturer's specifications, the lengths specified in Table 1217.4. Actual loop lengths shall be determined by spacing, flow rate, and pressure drop requirements as specified in the system design.
For the purpose of system balancing, each individual loop shall have a tag securely affixed to the manifold to indicate the length of the loop and the room(s) and area(s) served.
TABLE 1217.4 MAXIMUM LENGTH OF CONTINUOUS TUBING FROM A SUPPLY-AND-RETURN MANIFOLD ARRANGEMENT
|NOMINAL TUBE SIZE (inches) ||MAXIMUM LOOP LENGTH (feet)|
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm