McQuay AGZ 065A User Manual

10 AGZ 035A through 065A IOMM AGZ-3
Water Connections
Bring water piping to the evaporator through the side between the vertical supports. Provide taps for
the connection of pressure gauges and thermometers in the inlet and outlet lines.
Glycol Solutions
The use of a glycol/water mixture in the CDE evaporator to prevent freezing will reduce system
capacity and efficiency and increase pressure drop. The system capacity, required glycol solution flow
rate, and pressure drop with glycol may be calculated using the following formulas and tables.
1. Capacity – Multiply the capacity based on water by the Capacity correction factor from Table 5.
2. Flow – Multiply the water evaporator flow by the Flow correction factor from Table 5 determine
the increased evaporator flow due to glycol.
If the flow is unknown, it can be calculated from the following equation:
)
)(24
(gpm) Flow Glycol FactorCorrectionFlow
TDelta
glycolCapacityTons
×
−
×
=
For Metric Applications – Use the following equation for metric applications:
FactorCorrectionFlow
T
D
elta
CapacitykW
×
−×
=
18.4
(l/s) Flow Glycol
3.
Pressure drop -- Multiply the water pressure drop from Figure 7 by Pressure Drop correction
factor from Table 4 or Table 5 to obtain corrected glycol pressure drop. High concentrations of
propylene glycol at low temperatures may cause unacceptably high pressure drops.
4.
Power -- Multiply the water system power by Power correction factor from Table 4 or Table 5.
Test coolant with a clean, accurate glycol solution hydrometer (similar to that found in service
stations) to determine the freezing point. Obtain percent glycol from the freezing point table below.
It is recommended that a minimum of 25% solution by weight be used for protection against
corrosion.
CAUTION
Do not use an automotive grade antifreeze. Industrial grade glycols must be
used. Automotive antifreeze contains inhibitors which will cause plating on
the copper tubes within the chiller evaporator. The type and handling of
glycol used must be consistent with local codes.
Note: The procedure
does not specify the
type of glycol. Use
the derate factors
found in Table 4 for
corrections when
using ethylene glycol
and those in Table 5
for propylene glycol.

McQuay AGZ 065A Specifications

General

Brand	McQuay
Model	AGZ 065A
Category	Chiller
Language	English