Wells RW-16 thru RW-36 Installation Manual download pdf (Page 11)

RW SERIES INSTALLATION MANUAL

Field Connected Water Piping cont.

Before final connection to the unit, the supply and return hose

kits must be connected to each other, bypassing the unit, and

the system flushed to remove dirt, piping chips and other foreign

material. Normally, a combination balancing and close-off (ball)

valve is installed at the return, and a rated gate or ball valve is

installed at the supply. The return valve can be adjusted to obtain

the proper water flow. The valves allow the unit to be removed for

servicing.

The proper water flow must be delivered to each unit whenever the

unit heats or cools. The proper flow rate cannot be accurately set

without measuring the water pressure drop through the refrigerant-

to-water heat exchanger. A3GPMflowrateperton[0.054LPS

perkW]ofcoolingcapacity(2.25GPMperton[0.0404LPSper

kW]minimum)isrequired.

NOTE: The placement and connection of the water circulating

pump(s) must be taken into consideration prior to designing the

final water piping systems.

ClosedLoopTower/BoilerSystems

The water loop is usually maintained between 60°F [15.5°C] and

90°F [32.2°C] for proper heating and cooling operation. This is

accomplished with a cooling tower and a boiler.

To reject excess heat from the condenser water loop, the use of a

closed-circuit evaporative cooler or an open type cooling tower with

a secondary heat exchanger between the tower and the condenser

water loop is recommended. If an open type cooling tower is

used without a secondary heat exchanger, continuous chemical

treatment and filtering of the water must be performed to ensure

the water is free from damaging materials.

CAUTION:Waterpipingexposedtooutside

temperaturemaybesubjecttofreezing.

OpenLoopWellWaterSystems

Installation of an open loop system is not recommended without

using a secondary heat exchanger unless water quality guidelines

are met.

EarthCoupledSystems

All supply and return water piping should be insulated to prevent

excess condensation from forming on the water lines. Ensure

pumping system is capable of providing adequate flow rate at

the system pressure drop, 3.0 GPM per ton [0.054 LPS per kW]

(source side) is recommended. Antifreeze in the loop is strongly

recommended.

HeatingwithHighSourceTemperatures

Heating water with a water to water unit using high source

temperatures can lead to operating conditions that fall outside

of the system operating range. The condition occurs when the

loop (source) temperature exceeds 70°F [21.1°C] with a full

flow of 3 GPM per ton [0.054 LPS per kW]. Under this scenario,

the evaporating temperature can fall outside of the compressor

operating window.

To allow the system to operate correctly, restricting the source side

flow when the evaporating temperature exceeds 55°F [12.7°C] is

recommended. One way of accomplishing this is to use a flow-

restricting valve on the source loop circuit that is controlled by

the evaporating temperature. Locate the sensing device on the

refrigerant inlet of the evaporator. In dual circuit systems, the

company recommends monitoring both circuits and controlling off

the sensor that reads the highest temperature.

As an alternative to the evaporating temperature, the suction line

temperature can be monitored with the same control capability. In

this control, temperature should be a maximum of 65°F [18.3°C].

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Wells RW-16 thru RW-36 Installation Manual Page 11

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