8
513 01 3402 02
3. Size ductwork for cooling air quantity (cfm). The minimum
air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities
below those recommended.
4. Seal, insulate, and weatherproof all external ductwork.
Seal, insulate and cover with a vapor barrier all ductwork
passing through conditioned spaces. Follow latest Sheet
Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
Association (ACCA) minimum installation standards for
residential heating and air conditioning systems.
5. Secure all ducts to building structure. Flash, weatherproof,
and vibration
−
isolate duct openings in wall or roof
according to good construction practices.
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)
DISCHARGE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before performing service or maintenance operations
on the system, turn off main power to unit and install
lockout tag.
!
WARNING
1. Open all electrical disconnects and install lockout tag
before starting any service work.
2. Remove horizontal (metal) ductcovers to access vertical
(downflow) discharge duct knockouts in unit basepan.
(See FIGURE 7.)
3. To remove downflow return and supply knockout covers,
break front and right side connecting tabs with a screw
driver and hammer. Push cover down to break rear and
left side tabs.
NOTE
: These panels are held in place with tabs similar to an
electrical knockout. Reinstall horizontal duct covers (FIGURE 7)
shipped on unit from factory. Insure openings are air and
watertight.
NOTE
: The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
nonresidence
−
type air conditioning and ventilating systems,
NFPA 90A or residence
−
type, NFPA 90B; and/or local codes
and ordinances.
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Units are shipped for side shot installation.
2. Select and size ductwork, supply
−
air registers, and
return
−
air grilles according to American Society of
Heating, Refrigeration and Air Conditioning Engineers
(ASHRAE) recommendations.
3. Use flexible transition between rigid ductwork and unit to
prevent transmission of vibration. The transition may be
screwed or bolted to duct flanges. Use suitable gaskets to
ensure weather
−
tight and airtight seal.
4. All units must have field
−
supplied filters or accessory filter
rack installed in the return
−
air side of the unit.
Recommended sizes for filters are shown in Table 1.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.
6. Adequately insulate and weatherproof all ductwork located
outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest
issue of Sheet Metal and Air Conditioning Contractors
National Association (SMACNA) and Air Conditioning
Contractors of America (ACCA) minimum installation
standards for heating and air conditioning systems.
Secure all ducts to building structure.
7. Flash, weatherproof, and vibration
−
isolate all openings in
building structure in accordance with local codes and
good building practices.
FIGURE 7
Supply and Return Duct Opening
Horizontal Duct Covers
Basepan
Downflow
(Vertical)
Supply
Knockout
Basepan
Downflow
(Vertical)
Return
Knockout
Step 6 — Provide for Condensate Disposal
NOTE
: Ensure that condensate
−
water disposal methods comply
with local codes, restrictions, and practices.
The PH4E units dispose of condensate through a 3/4 in. NPT
female fitting that exits on the compressor end of the unit.
Condensate water can be drained directly onto the roof in
rooftop
installations (where permitted) or onto a gravel apron in
ground
level installations. Install a field
−
supplied condensate
trap at end of
condensate connection to ensure proper drainage.
Make sure that
the outlet of the trap is at least 1 in. (25 mm)
lower than the drain
−
pan
condensate connection to prevent the
pan from overflowing. Prime
the trap with water. When using a
gravel apron, make sure it slopes
away from the unit.
If the installation requires draining the condensate water away
from the unit, install a field
−
supplied 2
−
in. (51mm) trap at the
condensate connection to ensure proper drainage. Condensate
trap is available as an accessory or is field
−
supplied. Make sure
that the outlet of the trap is at least 1 in. (25 mm) lower than the
unit drain
−
pan condensate connection to prevent the pan from
overflowing. Connect a drain tube using a minimum of
field
−
supplied 3/4
−
in. PVC or field
−
supplied 3/4
−
in. copper pipe
at outlet end of the 2
−
in. (51 mm) trap. (See FIGURE 8) Do not
undersize the tube. Pitch the drain tube downward at a slope of
at least 1 in. (25 mm) every 10 ft (3 m) of horizontal run. Be sure
to check the drain trough for leaks. Prime the trap at the
beginning of the cooling season start
−
up.