10 ALR 110F – 150F Product Manual ALR2-3
Performance Adjustment Factors
Ethylene and Propylene Glycol Factors
ALR units can operate with a leaving chilled fluid temperature range of 20°F (-6°C) to 60°F (10°C). A
glycol solution is required when leaving chilled fluid temperature is below 40°F (4.6°C). The use of
glycol will reduce the performance of the unit depending on concentration. Manufacturers do not
recommend the use of solutions of less than 25 percent due to the possibility of insufficient corrosion
protection.
Altitude Correction Factors
Performance tables are based at sea level. Elevations other than sea level affect the performance of the
unit. The decreased air density will reduce condenser capacity, consequently reducing the unit's
performance. For performance at elevations other than sea level refer to Table 3.
Evaporator Temperature Drop Factors
Performance tables are based on a 10 degree F (5.5 degree C) temperature drop through the evaporator.
Adjustment factors for applications having temperature drops from 6 degree F to 16 degree F (3.3
degree C to 8.9 degree C) are in Table 3. Temperature drops outside this range may affect the control
system's capability to maintain acceptable control and are not recommended.
The maximum water temperature that can be circulated through the evaporator in a non-operating
mode is 100°F (37.8°C).
Table 1, Ethylene Glycol
Freeze Point%
E.G.
°F °C
Capacity Power Flow PD
10 26 -3 0.991 0.996 1.013 1.070
20 18 -8 0.982 0.992 1.040 1.129
30 7 -14 0.972 0.986 1.074 1.181
40 -7 -22 0.961 0.976 1.121 1.263
50 -28 -33 0.946 0.966 1.178 1.308
Table 2, Propylene Glycol
Freeze Point%
P.G.
°F °C
Capacity Power Flow PD
10 26 -3 0.987 0.992 1.010 1.068
20 19 -7 0.975 0.985 1.028 1.147
30 9 -13 0.962 0.978 1.050 1.248
40 -5 -21 0.946 0.971 1.078 1.366
50 -27 -33 0.929 0.965 1.116 1.481
Units operating with glycol solutions are not included in the ARI
Certification Program.
Fouling factor
Performance tables are based on a fouling factor of 0.0001 ft
2
x hr x °F/Btu (0.0176 m
2
x °C/kW) per
ARI Standard 550/590-98. As fouling is increased, performance decreases. Refer to Table 3 for
performance at other than 0.0001 (.0176) fouling factor.
Foreign matter in the chilled water system will adversely affect the heat transfer capability of the
evaporator, and could increase the pressure drop and reduce the water flow. To ensure optimum unit
operation, proper water treatment must be maintained.
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