Honeywell Design and Application User Manual

Section 6 - W7459 Economizer Module
57 Honeywell Economizers 63-8594-02
W7459 Enthalpy Setpoint Chart
This is the psychrometric chart for the setpoint
on the W7459 enthalpy modules. It is similar
to the charts for the H705 except for the
enthalpy high limit line to the right of the A
curve. This is a specialized limit used only in
the W7459D, W6210D, W7210D and W7212
controllers. When the enthalpy of both the
return and outside air is to the right of the limit
line the outside air dampers are closed to the
minimum position and the mechanical cooling
is energized.
When using differential enthalpy the outdoor
air is compared to the return air and you set
the potentiometer to "D" to prevent the return
air from being to the left of the enthalpy curve.
40 °F
4 °C
50 °F
10 °C
60 °F
16 °C
70 °F
21 °C
80 °F
27 °C
90 °F
32 °C
100 °F
38 °C
110 F
43 °C
120 °F
49 °C
35 °F
2 °C
45 °F
7 °C
55 °F
13 °C
65 °F
18 °C
75 °F
24 °C
85 °F
29 °C
95 °F
35 °C
105 °F
41 °C
115 °F
46 °C
°F
09
)
°C
23(
BLUB TEW
°F
58
)
°C
92(
BLUB TEW
°F
08
)
°C
72(
BLUB TEW
°F
57
)
°C
42(
BLUB TEW
°F
06
)
°C
61(
BLUB TEW
54
°F
(
7
)
°C
BLUB TEW
04
°F
(
4
)
°C
BLUB TEW
53
°F
(
2
)
°C
BLUB TEW
HR %08
HR %07
HR %03
HR %04
HR %05
HR %06
HR %09
HR %01
HR %02
HR %001-NOITARUTAS
°F
07
)
°C
12(
BLUB TEW
°F
56
)
°C
81(
BLUB TEW
DRY BULB TEMPERATURES
15
BTU/LB
34.8 k-
J/kg
20 BTU/LB
46.4 k-J/kg
25 BTU/LB
58 k-J/kg
30 BTU/LB
69.7 k-J/kg
35 BTU/LB
81.4 k-J/kg
40 BTU/LB
92.8 k-J/kg
45 BTU/LB
104.5 k-J/kg
50 BTU/LB
116 k-J/kg
A
B
C
D
HIGH LIMIT
CURVE FOR
W7459 D,
W6210D AND
W7210D
M25283A
°F
55
)
°C
31(
BLUB TEW
°F
05
)
°C
01(
BLUB TEW
Control Curve
Control Point
(Approximate Temperature
at 50% Humidity)
A 73°F (23°C)
B 70°F (21°C)
C 67°F (19°C)
D 63°F (17°C)
Knob turned
to D
For Differential Enthalpy
(2 Sensor)

Honeywell Design and Application Specifications

General

Brand	Honeywell
Model	Design and Application
Category	Controller
Language	English