IH/WC Series Dehumidifier
Outdoor Air Design Parameters
for Indoor Pools
I
NTRODUCTION
Outside Air Ductwork with
0.20" - 0.45" wc Pressure Drop
ASHRAE 62 recommends that outdoor air be
introduced to commercial pool facilities. Please refer
to DESERT AIRE Technical Bulletin No. 5 for a detailed
analysis of these recommendations.
To ensure that the moisture removal capacity of the
DESERT AIRE dehumidifier is maintained, the outdoor
air must be balanced with the return air. The outdoor
air must be introduced between the evaporator and
reheat coils, as shown in the diagram.
Outside Air
Pre-Heater *
Dehumidifier
Supply
Air
The exhaust fan should be sized for the same or slightly more
CFM as the outdoor air volume and be interlocked to operate
in conjunction with the motorized outdoor air damper.
D AMPER OPERATION
The contractor must install the air filter, two-position motorized damper, and appropriate insulated duct, per code and
local regulations. As an option, DESERT AIRE can supply the
filter/damper combination factory installed.
R
E
H
E
A
T
Electrical
Panel
Terminal
Strip
D1
E
V
A
P
Outside
Air
Air Filter
Motorized Outside
Air Damper
Return
Air
To Damper Actuator (Dry Contact)
To Damper
Power Supply
D2
E1
E2
To Exhaust Fan
(Dry Contact)
*Outside air pre-heater is necessary in IH/WC applications where mixed air temperatures
may fall below 45°F and outside air compliance is required at all times.
A IR FLOW BALANCE
The IH/WC Series utilizes a two-position damper, which allows
air to bypass the evaporator coil. With the outdoor air damper
opening and closing, the amount of outdoor air changes and a
new balance must be achieved across the evaporator coil to
ensure proper moisture removal (i.e., to maintain velocity
across the coil face). The two-position damper obtains this balance
automatically. System air flow balance must be established
during start-up by the installing contractor.
Mode
Damper Position
Occupied
Open
Unoccupied
Closed
Model
O/A CFM
O/A Flange Size
Loss of Blower
Closed
IH/WC 100
125
5” x 10”
< 45°F Mixed Air Temperature
Closed
IH/WC 200
250
5” x 10”
IH/WC 300
350
6” x 14”
IH/WC 500
500
8” x 14”
IH/WC 750
900
10” x 16”
IH/WC 1000
1000
12” x 16”
IH/WC 1200
1300
12” x 18”
IH/WC 1500
1800
12” x 26”
All IH/WC models are equipped with an air temperature sensor which monitors conditions inside the unit. To prevent
internal condensation from freezing when frigid outdoor air
mixes with warm, humid air, a call for outdoor air will be overridden whenever mixed air temperatures in the blower compartment fall below 45°F.
NOTE: In applications where outdoor air code compliance is
required at all times and where outdoor temperatures may fall
below freezing, preheating of outdoor air will be required.
Please note that this caution is not specific to DESERT AIRE
units. Customers should be aware of the design details for
handling frigid outdoor air with any unit they are evaluating.
8300 West Sleske Court
Milwaukee, WI 53223
(414) 357-7400
FAX: (414) 357-8501
www.desert-aire.com
217 4/02