1220.2 Snow and Ice Melt Controls
The maximum loop length of continuous tubing from a supply-and-return manifold arrangement shall not exceed the lengths specified by the manufacturer or, in the absence of manufacturer's specifications, the lengths specified in Table 1220.2.1. Actual loop lengths shall be determined by spacing, flow rate, and pressure drop in accordance with the system design.
TABLE 1220.2.1 LOOP LENGTHS FOR SNOW AND ICE MELT SYSTEMS1, 2
|NOMINAL TUBE SIZE (inches)||MAXIMUM ACTIVE LOOP LENGTH (feet)||TOTAL LOOP LENGTH (feet)|
|PE—RT and PEX Tubing|
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm
1 The total PE-RT and PEX loop lengths consist of two separate sections, the active loop, and the leader length. The active loop is installed within the heated slab. The leader length is the total distance to and from the manifold and heated slab, including any vertical distances.
2 The manifolds shall be installed as close to the snow melt area as possible.
3 In concrete use minimum Type L copper water tubing. In bituminous pavement use a Type K copper water tubing.