Aprilaire 1700 Ducting, Drain Line, Hanging, Orientation of trap prior to

DUCTING

The Aprilaire Dehumidifier is supplied with two 8” round collars. These are packaged with a condensate trap inside the unit behind the filter access panel. When installing the collar make sure the foam seal uniformly contacts the cabinet and secure with 4 screws (not included). UL approved 8” diameter, insulated flexible duct is recommended for all connections. Rigid metal duct may be used. The duct should be capable of handling at least 2” w.c. of positive and 0.75” w.c. of negative pressure. All joints and seams must be sealed.

Design air flow is 275 CFM @ 0.6” w.c. This is equivalent to 70 ft. of 8” duct on the inlet and outlet side of the dehumidifier. Elbows, turns and the static pressure of the HVAC equipment will affect the airflow through the dehumidifier.

•For optimal moisture removal, airflow should be at or above 275 CFM.

•The total static pressure across the dehumidifier must not exceed 0.8” w.c. Check all pressures with the HVAC fan on.

•The outlet from the dehumidifier to the HVAC supply duct must be located at least 6” downstream of the cooling coil.

•If connected to HVAC ductwork, the dehumidifier inlet must be located at least 6” upstream of the HVAC system air cleaner. This will prevent any trapped particulates from being drawn into the dehumidifier.

•If UV Germicidal lamps are installed in the HVAC system, use appropriate methods to protect the flexible duct from the UV light.

•If air noise is a problem, install at least 5 feet of acoustical flexible duct on the outlet and inlet of the dehumidifier.

DRAIN LINE

The included condensate trap
must be installed to the Model		FIGURE 1
1700. Use PVC primer and	Drain Outlet
cement to connect the trap to the		1/2”
drain outlet on the Model 1700.		Drain Trap
The drain outlet is located near		2 1/2”
the On/Off toggle switch. Note	High Side
		Low Side
orientation of trap prior to

cementing. The high side of the	90-961
trap mates with the Model 1700. The adjustable legs on
the Model 1700 must be disengaged approximately 1” to		FIGURE 2
accommodate the trap. Complete the assembly by piping
the trap to a drain. The trap must be primed with water
prior to start-up.
If the 1700 is installed in an attic or in an area where
flooding is a potential problem, it should be installed in a		3“ MIN
secondary drain pan with a condensate overflow safety		CLEARANCE FOR
switch. See page 12 for condensate overflow safety		ACCESS PANEL
switch wiring.
		TOP VIEW
HANGING		20” MINUMUM
		CLEARANCE FOR FILTER
		(EITHER SIDE)
If hanging the unit, use two unistruts to support the base		FILTER
on the outside edges of the feet locations. There must
be at least 20” of clearance in front of one of the filter		6" MIN CLEARANCE FOR FILTER
access doors to allow removal of the filter.		90-970
		3