Sterling QVSB - Manual (Page 5)

5
INSTALLATION
Do not install unit heaters in
corrosive or fl ammable atmospheres! Premature
failure of, or severe damage to the unit will result!
Avoid locations where extreme
drafts can affect burner operation. Unit heaters
must not be installed in locations where air for
combustion would contain chlorinated, haloge-
nated or acidic vapors. If located in such an
environment, premature failure of the unit will
occur!
Since the unit is equipped with an automatic gas ignition
system, the unit heater must be installed such that the gas
ignition control system is not directly exposed to water
spray, rain or dripping water.
NOTICE: Location of unit heaters is related directly to
the selection of sizes (refer to Figure 3). Basic rules
are as follows:
Figure 3
MOUNTING HEIGHT: Unit Heaters must be installed at
a minimum of 8 feet (2.4m) above the fl oor, measured to
the bottom of the unit. At heights above 8 feet (2.4m),
less effi cient air distribution will result. Occasionally unit
heaters must be mounted at heights of 12 to 16 feet (3.7
to 4.9m) in order to clear obstacles. When this is the
case, it is advisable to use centrifugal blower unit heaters.
AIRCRAFT HANGARS: Unit Heaters must be installed
in aircraft hangars and public garages as follows: In
aircraft hangars, unit heaters must be at least 10 feet
(3.0m) above the upper surface of wings or engine
enclosures of the highest aircraft to be stored in the
hangar and 8 feet (2.4m) above the floor in shops,
offi ces and other sections of the hangar where aircraft
are not stored or housed. Refer to current ANSI/NFPA
No. 409, Aircraft Hangars. In Canada, installation is
suitable in aircraft hangars when acceptable to the
enforcing authorities.
PUBLIC GARAGES: In repair garages, unit heaters
must be located at least 8 feet (2.4m) above the floor.
Refer to the latest edition of NFPA 88B, Repair Garages.
In parking structures, unit heaters must be installed so
that the burner fl ames are located a minimum of 18
inches (457mm) above the floor or protected by a
partition not less than 18 inches (457mm) high. However,
any unit heater mounted in a parking structure less than
8 feet (2.4m) above the fl oor must be equipped with an
OSHA approved fan guard. Refer to the latest edition of
NFPA 88A, Parking structures.
In Canada, installation must be in accordance to the
latest edition of CSA-B149 “Installation Codes for Gas
Burning Appliances and Equipment.”
AIR DISTRIBUTION: Direct air towards areas of
maximum heat loss. When multiple heaters are involved,
circulation of air around the perimeter is recommended
where heated air fl ows along exposed walls. Satisfactory
results can also be obtained where multiple heaters are
located toward the center of the area with heated air
directed toward the outside walls. Be careful to avoid all
obstacles and obstructions which could impede the warm
air distribution patterns. Heat throw distances are
presented in Table 2, and Figure 4.
ft. 100,000 125,000 150,000 175,000 200,000 225,000 250,000 300,000 350,000 400,000
(m) (29.3) (36.6) (43.9) (51.2) (58.6) (65.9) (73.2) (87.8) (102.5) (117.1)
8 60 65 70 75 80 85 90 105 110 120
(2.4) (18.3) (19.8) (21.3) (22.9) (24.4) (25.9) (27.4) (32.0) (33.5) (36.6)
10 54 56 60 64 68 72 78 90 95 100
(3.0) (16.5) (17.1) (18.3) (19.5) (20.7) (21.9) (23.8) (27.4) (29.0) (30.5)
12 44 46 49 57 61 65 68 80 84 90
(3.7) (13.4) (14.0) (20.7) (17.4) (18.6) (19.8) (20.7) (24.4) (25.6) (27.4)
15 NR NR 45 49 52 56 60 70 74 80
(4.6) (22.6) (14.9) (15.8) (17.1) (18.3) (21.3) (22.6) (24.4)
20 NR NR NR NR 46 50 54 63 66 70
(6.1) (14.0) (15.2) (16.5) (19.2) (20.1) (21.3)
UNIT SIZE BTU/Hr (kW)
“H”
NR = Not recommended H = Distance from fl oor to bottom of the unit.
D2787
Table 2 - Standard Applications Heat Throw Distances (see fi gure 4)