Ventilation Or Air Cycling - Aprilaire 1750A Installation Instructions Manual

VENTIlATION OR AIR CyClING

The dehumidifier has outputs available to open a normally closed damper and
introduce outdoor air though an outdoor air intake duct . Ventilation is controlled by
the Cycle Period switches, Cycle Time potentiometer, and Vent-Auto/Vent-Timed
switches . If a normally closed ventilation damper is not installed, the dehumidifier
will function in Air Cycling mode, activating the HVAC blower to cycle air through
the home based on the Cycle Period and Cycle Time .
DUCTING & WIRING
fIGURE 19 – Whole-Home with Ventilation
DEHUMIDIFIED AIR IS SUPPLIED
DOWNSTREAM FROM A-COIL TO
MINIMIZE EVAPORATION OFF A-COIL
SUPPLY DUCT
HVAC / FURNACE
115 VAC
CIRCUIT
FLOOR DRAIN
DEHUMIDIFIER
CONDENSATE HOSE
(TO COMMON DRAIN OR OUTSIDE)
Ducting Note: Direct ducting the ventilation intake duct to the
dehumidifier inlet duct is acceptable if the incoming temperature
of the mixed air will be greater than 40°F and less than 100°F.
DETERMINE VENTIlATION REQUIREMENTS
CAlCUlATING AIRflOW REQUIREMENT
1 . The MINIMUM ventilation requirement is calculated using
ASHRAE 62 .2-2007 .
ASHRAE Airflow in CFM = [House Area in Sq . Ft . x 0 .01]
+ [(Number of Bedrooms +1) x 7 .5]
Notes: Use 'Number of Bedrooms +1' or the 'Number of
Occupants', whichever is larger .
2 . Table 3 shows calculated airflow values to the nearest 5 CFM .
If more outdoor air is required, a second device is advised .
3 . Record the Required CFM . __________
12
A-COIL
RETURN
DUCT
NORMALLY CLOSED
VENT DAMPER
AIR IS PULLED FROM
RETURN DUCT
90-1536
Required Components
Aprilaire Model 6506, 6" Normally Closed Damper
24 VAC Transformer (10VA min .) for Ventilation Damper
Optional Component
8052 Outdoor Temperature Sensor
fIGURE 20 – Ventilation Wiring
6" NORMALLY
CLOSED DAMPER
FUNCTIONS IN
THERMOSTAT
AIR CYCLING
MODE IF
R
DAMPER NOT
C
INSTALLED
G
W
Y
OPTIONAL OUTDOOR
TEMPERATURE SENSOR
See page 14 for outdoor
temperature sensor installation.
TAblE 3 – CfM Required
House Sq. ft.
2
1000 35
1500 40
2000 45
2500 50
3000
55
3500
24 VAC
(10 VA min)
TRANSFORMER DEHUMIDIFIER
CONTROL BOARD
HVAC EQUIPMENT
R
C
G
W
Y
Number of bedrooms
3 4 5
40 50
45 55 60
50 60 65
55 65 70
60 70 75
75 80
90-1537
6
70
75
80
85
90