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Marvair ComPac AVHDA I&O Manual 03/2019 Rev.3
standards. Marvair strongly recommends referring to the current edition of the National Fire Pro-
tection Association Standards 90A and 90B
before
designing and installing duct work.
The duct
system must be engineered to insure sufficient air flow through the unit to prevent over-heating of
the heater element. This includes proper supply duct sizing, sufficient quantity of supply registers,
and adequate return and filter areas. Duct work must be of correct material and must be properly
insulated. Duct work must be constructed of galvanized steel with a minimum thickness of .019
inches. Duct work must be firmly attached, secured, and sealed to prevent air leakage. See section
2.4 for additional duct work requirements.
5.
Clearances:
Note the minimum clearances required for proper operation and service.
MODEL
MIN. CLEARANCE
AROUND SIDES
(SINGLE UNIT)
MIN. CLEARANCE BETWEEN
UNITS (TWO UNITS)
MIN. SPACE
ABOVE UNIT
MIN. SPACE
BEHIND UNIT
AVHDA90
24 inches (61 cm)
24 inches (61 cm)
24 inches (61 cm) 120 inches (305 cm)
Table 9. Minimum Clearances
6.
Codes:
Make sure your installation conforms to all applicable electrical, plumbing, building, and municipal
codes. Some codes may limit installation to single story structures.
7.
Electrical Supply:
The power supply must have the appropriate voltage, phase, and ampacity for the model selected.
Voltage must be maintained above minimum specified values listed below. Refer to the data sticker
on the unit for ampacity requirements.
Electrical Rating Designations*
A
D
Z
Nominal Voltage
208/230
460
575
Phase
1
3
3
Minimum Voltage
197
414
518
Maximum Voltage
253
506
632
* Letters refer to model number code designations. Refer to page 5.
Table 10. Voltage Limitations
2.3 Installation Materials
The AVHDA90 is shipped with a top bracket and lifting brackets. The top bracket provides a method of
sealing the top of the unit from water intrusion. The bracket is shipped attached to the top of the unit.
Before installing the unit, remove the bracket and reattach as described in Section 2.5
The Lifting brackets are shipped attached to the back panel of the unit. These brackets provide a method
for lifting it. The installation of the brackets is described in Section 2.6.
