NORTH, EAST
OR WEST SIDE
OF HOME
OUTDOOR
TEMPERATURE
SENSOR
SENSOR
SENSOR
BRACKET
ABOVE EXPECTED
SNOW LINE
OUTDOOR
TEMPERATURE SENSOR
LEADS
36" MAX.
CENTER LINE
OUTSIDE WALL
B2202617-D
B2202617-E
OUTDOOR TEMPERATURE SENSOR INSTALLATION
The 58N66 Outdoor Temperature Sensor should be installed
outside in a shaded location, or in the outdoor air intake
duct.
DETERMINE VENTILATION REQUIREMENTS
Calculating Airflow Requirement
1. The MINIMUM ventilation requirement is calculated
using ASHRAE 62.2-2010.
ASHRAE Airflow in CFM = [House Area in Sq. Ft. x 0.01] +
[(Number of Be1) x 7.5]
NOTE:
Use ‘Number of Be 1’ or ‘Number of
Occupants’, whichever is larger.
2.
Table 1
shows the calculated airflow values to the
nearest 5 CFM.
3. Record the required CFM. ________
Table 1. CFM Required
House Sq. Ft.
Number of Bedrooms
2
3
4
5
6
1000
35
40
50
1500
40
45
55
60
70
2000
45
50
60
65
75
2500
50
55
65
70
80
3000
55
60
70
75
85
3500
75
80
90
Determine Fresh Air Delivery Rate
1. Measure the negative static pressure of the return system
at the location where the fresh air intake duct enters the
return duct or dehumidifier inlet.
2. See
Table 2
for estimated inlet airflow in CFM, based
on duct type, length and available negative pressure.
Use an airflow measuring device for a more accurate
airflow delivery rate.
3. Record the delivered CFM. ________
Figure 27. ODT Mounted Outside
Figure 28. ODT Mounted in Intake Duct
Table 2. CFM Delivered
Duct Length
Negative Static Pressure ("w.c.) as Measured for Return Duct or Plenum
0.05
0.1
0.15
0.2
0.25
0.3
Flex
Pipe
Flex
Pipe
Flex
Pipe
Flex
Pipe
Flex
Pipe
Flex
Pipe
10 ft.
60
65
85
90
105
110
120
125
135
140
150
160
20 ft.
55
60
80
85
100
105
115
120
130
135
140
150
30 ft.
50
55
75
80
95
100
110
115
125
130
130
140
NOTE:
For the table above, 6" flex duct is laid loose with two, wide 90° bends and a fully opened damper. Rigid pipe values
are based on 6" duct, two 90° elbows, and a fully open damper. In both cases, the air intake is through a metal vent hood
with inlet screen. Airflow may need to be adjusted up or down for variations in duct system.
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