I-UDSA-UK (02-19) PN 06 00116 UDSA R3, page 9
The presence of chlorine vapours in the combustion air of gas-
fired heating equipment presents a potential corrosion hazard.
Chlorine, found usually in the form of Freon or degreaser
compounds when exposed to a flame will precipitate from the
compound, and go into solution with any condensation that is
present in the heat exchanger or associated parts. The result
is hydrochloric acid which readily attacks all metals. Care
should be taken to separate these vapours from the combus-
tion process. This may be done by wise location of the unit
flue and combustion air terminals with regard to exhausters or
prevailing wind directions. Chlorine is heavier than air. Keep
this fact in mind when determining installation location of the
heater in relation to building exhaust systems.
Where chlorine vapours are prevalent heaters with special
grade 316 A1SI stainless steel heat exchangers are recom-
mended.
Hazards of Chlorine - apply to the location of the
combustion air inlet
Remark
: Flue requirements may affect location. Consult
section 7 before making a final determination.
Caution :
Do not locate the heater where it may be exposed
to water.
Use the minimum clearances in section 5 and the throw data in
the technical data table of section 6 when determining where to
suspend the heater. Recommended minimum height is 2.5 mm.
For best results, the heater should be placed with certain
rules in mind. Always ensure that minimum clearances are
maintained. Locating a unit heater above the maximum recom-
mended height can result in significant air stratification. When
possible, heaters should be arranged to blow toward or along
exposed wall surfaces.
Suspended heaters are most effective when located as close to
the working zone as possible, but care should be exercised to
avoid directing the discharged air directly on to room occupants.
Partitions, columns, counters, or other obstructions should be
taken into consideration when locating the unit heater so that a
minimum quantity of airflow will be deflected by such obstacles.
When units are located in the centre of the space to be heated,
the air should be discharged toward the exposed walls. In large
areas, units should be located to discharge air along exposed
walls with extra units provided to discharge air in toward the
centre of the area. For optimum results heaters are best used in
conjunction with recirculating air fans suspended at high level.
8
LOCATION OF HEATER
9
HANGING THE HEATER
Warning: Check the supporting structure to verify
that it has sufficient load-carrying capacity to support
the unit weight. Suspend the heater only from the
threaded nut retainers or with a manufacturer pro-
vided kit. DO NOT suspend from the heater cabinet
panels.
Do not place or add additional weight to the suspend-
ed heater.
Before suspending the heater, check the supporting structure
to verify that it has sufficient load-carrying capacity to support
the weight (refer to Table 6a) of the unit.
Table 6a : Unit Weights
UDSA-4E
Weight (kg)
UDSA-4E
Weight (kg)
011
33
055
114
015
38
064
118
020
40
073
143
025
54
085
160
030
57
100
179
035
86
120
245
043
99
145
263
050
102
Leave the unit on the pallet. If the bottom of the unit is not
supported or protected damage can occur.
The heater is supplied with four point suspension. All points
must be used. Two threaded nut retainers are provided on each
side of the top of the heater. See Figure 6a for hanger rod size.
At those points where infiltration of cold air is excessive, such
as at entrance doors and shipping doors, it is desirable to locate
the unit so that it will discharge directly toward the source of
cold air, typically from a distance of 4.5 to 6.0 meters or install
a downflow unit over the door opening.
Be sure that the threaded hanger rods are locked to the heater
as illustrated in Figure 6a. Recommended maximum hanger
rod length is 1.8m. Where longer drops are required, ensure
that restraints are fitted to prevent excess lateral movement
and supports are adequately sized.
Most UDSA models can be mounted vertically using the rear
suspension points, as shown in Figure 6b. When installing the
heater in this manner, the minimum clearances listed in Table
6b must be observed.
Warning: If touched, the vent pipe and internal heater
surfaces that are accessible from outside the heater
will cause burns. Suspend the heater such that these
components cannot be touched.
Table 6b : Minimum Clearances (mm)
UDSA-4E
Y
*
Z
*
U
*
025
→
030
800
850
150
035
→
100
1000
850
200
*
See Figure 1a.
