Trane UH-PRC001-EN manual General Notes, HotWater System - Using Circulating Pump

Application Considerations

General Notes

The following general notes on piping propeller unit heaters are presented based on competent engineering and installation practice:

1.Suspend unit heaters securely with provisions for easy removal.

2.Make certain units hang level vertically and horizontally.

3.Provide for expansion in supply lines (note swing joints in suggested piping arrangements).

4.Provide unions adjacent to unit heaters in both supply and return laterals. Also provide shut-off valves in all supply laterals.

5.Use 45' angle runoffs from all supply and return mains.

6.Provide at least 7" (more if necessary) clearance above tops of Model P Projection Unit Heaters. Motors are removable from below on all sizes.

It is desirable to form dirt pockets with pipe of the same size as the return tapping of the unit heater. Pipe in the branch-off should be the same size as the tapping in the trap. Beyond the trap, the return lateral should be increased one size to the return main.

HotWater System – Using Circulating Pump

Overhead supply and return mains are used with bottom connections to mains. Manual vent (pet cock) is used at high point on return main. Automatic air vent may be substituted if desired. Refer to Figure AC-2.

Figure AC-3

High Pressure Steam System Overhead supply main is used with lower return main. Where steam pressure fluctuates over a wide range, a swing check valve should be placed in the return lateral between strainer and bucket trap to prevent reverse flow of condensate of flash steam when pressure drops suddenly.Top of bucket trap must be located below return outlet of coil for complete drainage of condensate. Refer to Figure AC-3.

Figure AC-2

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