Unit installation

IOMM ACZ1-2 ACZ 010A through 039A 7

Chilled Water System

Water Piping (Applicable when the Unit is Field Connected to a Water Type

Evaporator)

Local authorities can supply the installer with the proper building and safety codes required for

proper installation.

Install piping with minimum bends and changes in elevation to minimize pressure drop. Consider

the following when installing water piping:

1. Vibration eliminators to reduce vibration and noise transmission to the building.

2. Shutoff valves to isolate the unit from the piping system during unit servicing.

3. Manual or automatic air vent valves at the high points of the system. Install drains at the

lowest points in the system.

4. A means of maintaining adequate system water pressure (expansion tank or regulating valve).

5. Temperature and pressure indicators located at the unit to aid in unit servicing. Pressure

gauge taps must be installed in the chilled water inlet and outlet piping or as shown in Figure

6. A strainer or other means of removing foreign matter from the water before it enters the pump.

Place the strainer far enough upstream to prevent cavitation at the pump inlet (consult pump

manufacturer for recommendations). The use of a strainer will help prolong pump life and

keep system performance up.

7. A 40-mesh strainer is required in the water line just before the inlet of the evaporator. This

will help prevent foreign material from entering and decreasing the performance of the

evaporator.

8. If the unit is used as a replacement chiller on a previously existing piping system, flush the

system thoroughly before unit installation. Regular water analysis and chemical water

treatment on the evaporator is recommended immediately at equipment start-up.

9. When glycol is added to the water system for freeze protection, the refrigerant suction

pressure will be lower, cooling performance less, and water side pressure drop greater. If the

percentage of glycol is high, or if propylene is used instead of ethylene glycol, the added

pressure drop and loss of performance could be substantial. Reset the freezestat and low

leaving water alarm temperatures. The freezestat is factory set to default at 38°F (3.3°C).

Reset the freezestat setting to approximately 4 to 5 degrees F (2.3 to 2.8 degrees C) below the

leaving chilled water setpoint temperature.

10. Perform a preliminary leak check before insulating the piping and filling the system.

11. Piping insulation should include a vapor barrier to prevent condensation and possible damage

to the building structure.

Figure 4, Typical Field Evaporator Water Piping

Vent

Flow

Switch

Vibration

Eliminators

Drain

Outlet

Inlet

Isolation

Valves

Strainer