IM 676
9
Note: On units sizes 160E through 185E there is a diagonal bracket off of a vertical support
which will interfere with the water connection if brought in from the side. This brace can be
removed, but only after the unit is in place.
Refrigerant Charge
All units are designed for use with HCFC-22 and other refrigerants. See nameplate for specific
refrigerant used. Units are shipped with an operating charge. The operating charge
(using HCFC-22) for each unit is shown in the Physical Data tables beginning on page 12.
Glycol Solutions
The system glycol capacity, glycol solution flow rate in GPM, and pressure drop through the cooler
may be calculated using the following formulas and table.
1. Capacity -- Find the reduced capacity by multiplying the chiller’s capacity with water by the
capacity correction factor C.
2. Flow -- To determine evaporator gpm (or Delta-T) knowing Delta-T (or gpm) and capacity:
Glycol GPM
(from table)
=
×
−
×
24
capacity glycol
Delta
T
G
(
)
For Metric Applications -- To determine evaporator L/s (or Delta-T) knowing Delta-T (or L/s)
and kW:
Glycol L / s
(from table)
=
×
−
×
kW
Delta
T
Flow
4.18
3. Pressure drop -- To determine pressure drop through the evaporator, when using glycol, enter
the water pressure drop curve on page 11 at the actual glycol GPM. Multiply the water pressure
drop by PD correction factor from Table 4 or Table 5 to obtain corrected glycol pressure drop.
4. To determine the unit's power consumption when using glycol, multiply the water system kW by
factor kW.
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.
On glycol applications it is normally recommended by the supplier that a minimum of 25% solution
by weight be used for protection against corrosion.
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.
