Piping, Duct Work, Filters, Condensate Drain

Remove these covers for horizontal duct applications

Return

Supply

Remove these panels for downflow duct applications

Duct Cover Installation

Down Discharge Applications

Cut insulation around bottom openings and remove panels from the bottom of the unit, saving the screws holding the panels in place.

NOTE: Single phase models require installation of horizontal duct kit #20464501PDGK (medium chassis) and #20464502PDGK (large chassis).

DUCT WORK

Duct systems and register sizes must be properly designed for the C.F.M. and external static pressure rating of the unit. Duct work should be designed in accordance with the recommended methods of Air Conditioning Contractors of America Manual D (Residential) or Manual Q (Commercial). All ductwork exposed to the outdoors must include a weatherproof barrier and adequate insulation.

A duct system should be installed in accordance with Standards of the National Board of Fire Underwriters for the Installation of Air Conditioning, Warm Air Heating and Ventilating Systems. Pamphlets No. 90A and 90B.

The supply duct from the unit through a wall may be installed without clearance. However, minimum unit clearances as shown in the appendix must be maintained. The supply duct should be provided with an access panel large enough to inspect the air chamber downstream of the heat exchanger. A cover should be tightly attached to prevent air leaks.

For duct flange dimensions on the unit refer to the Unit Dimension illustration in the appendix.

For down-discharge applications, the ductwork should be attached to the roof curb prior to installing the unit. Duct work dimensions are shown in the roof curb installation manual.

If desired, supply and return duct connections to the unit may be made with flexible connections to reduce possible unit operating sound transmission.

FILTERS

CAUTION

TO PREVENT PROPERTY DAMAGE DUE TO FIRE AND LOSS OF EQUIPMENT EFFICIENCY OR EQUIPMENT DAMAGE DUE TO DUST AND LINT BUILD UP ON INTERNAL PARTS, NEVER OPERATE UNIT WITHOUT AN AIR FILTER INSTALLED IN THE RETURN AIR SYSTEM.

Filters are not provided with unit and must be supplied and exter- nally installed in the return duct system by the installer. An optional factory approved internal filter rack may also be used. A field-in- stalled filter grille is recommended for easy and convenient ac- cess to the filters for periodic inspection and cleaning. When installing filters, ensure the air flow arrows on the filter are pointing toward the circulator blower.

Refer to the unit filter size chart below for filter size information.

MINIMUM FILTER SIZE

NOMINAL SIZE (INCHES)	NOMINAL AREA (SQ. FT.)
10x20	1.4
14x20	1.9
14x25	2.4
15x20	2.1
16x20	2.2
16x25	2.8
20x20	2.8
20x25	3.5
25x25	4.3

NOTE: Filters must have adequate face area for the rated quantity of the unit. See the air delivery table below for recommended filter size. Size the filters in accordance with their manufacturer recom- mendations. Throwaway filters must be sized for a maximum face velocity of 300 feet per minute.

Area

Feet

Filter

Square

Nominal

ANE

1000

1500

2000

2500

3000

3500

500

Airflow - SCFM

PIPING

CONDENSATE DRAIN

The condensate drain connection of the evaporator is a half cou- pling of ¾” N.P.T. A trap must be provided to have Proper conden- sate drainage.

Unit	2" Minimum
Drain
Connection	3" Minimum
	3" Minimum
Flexible
Tubing-Hose	A Positive Liquid Seal
Or Pipe	Is Required

Install condensate drain trap as shown. Use ¾ “ drain connection size or larger. Do not operate without trap. Unit must be level or slightly inclined toward drain.