11
Air Handling Units
Connection of Heat Exchangers, Duct, Wiring
Steam Humidification
For a detailed description of installation, commissioning
and prescribed inspections of the steam humidification
built-in assembly, refer to the separate manual which is
a part of the accompanying documentation of the Aero-
Master Cirrus air-handling unit.
When installing the steam humidification assembly, obser
-
ve the following recommendations:
Air ducts leading through cold areas must be insulated
to avoid condensation.
The assembly must be situated in a non-freezing area.
The steam generator can be noisy (switching of soleno-
id valves); therefore, it is advisable to install it away from
quiet areas.
100°C hot and heavily mineralized water is drained
from the steam humidifier.
The following minimum distances (distances between
the steam humidifier and the following air-handling unit
components, where H represents the minimum evapora-
ting distance calculated for the given conditions) must be
observed to ensure proper operation of the steam humidi-
fier and the entire AeroMaster Cirrus air-handling unit:
Humidistat piping, humidity sensor, temperature sen-
sor: 5x H
Very fine filter: 2.5 x H
Heating elements, filter: 1.5 x H
Duct branch piece, duct elbow, air outlet, fan: 1x H
Note: If the H value is not known, it is advisable to make
the calculation with a minimum value of 1.0 m.
Condensate Drainage
Cooling, plate heat exchanger and steam humidification
blocks are equipped with stainless condensate draining
trays which terminate in an outlet for the condensate drai-
ning kit connection. The diameter of the neck for Cirrus air-
handling units is 32 mm. The condensate draining kits are
available as optional accessories. A separate condensate
draining kit must be used for each individual block.
The siphon height depends on the total pressure of the
fan, and ensures its proper functioning. The type of con-
densate draining kit must be designed in the course of
the air-handling unit calculation. The condensate draining
piping must end in free atmosphere, i.e. it must not end
directly in the closed sewerage system.
Before operating the air-handling unit or after being out
of operation for a longer period, it is necessary to fill the
siphon with water. The air-handling unit can also be equip-
ped with a siphon with a disconnecting trap and a ball
valve (only negative pressure blocks). This type of siphon
need not be filled with water before putting it into operati
-
on. If there is a risk of freezing, it is necessary to insulate
the siphon and condensate draining piping, respectively
keep the ambient temperature above freezing point, e.g.
with an electric heating cable!
Figure 21 – c
ondensate drainage
Siphon – positive pressure
Siphon – negative pressure
Siphon – negative pressure
(with a disconnecting trap)
Hmin (mm) = P (Pa) / 10 P – total fan pressure
The gas heater block is provided with a condensate drai-
nage outlet (1/2" pipe) to drain the condensate from the
combustion chamber.
Air-handling Duct Connection
The air ducting must be connected to the air-handling unit
via an elastic element to avoid the transfer of vibrations
and eliminate misalignment of the duct and inlet of the air-
handling unit. The connection must be performed so that
no loading from the air duct will be transferred to the inlet
panel of the air-handling unit and no deformation of this
panel will be possible.
The accessories must be installed in accordance with the
air-handling unit specification and the Installation Instructi
-
ons of the manufacturers of such accessories.
No other structures must obstruct the unit inspection door
opening, or unit operation and maintenance.
Electrical Equipment Wiring
Connection of the internal electrical equipment of the
air-handling unit can be made via the wiring grommets
which are situated on the service side of the air-handling
unit casing (the service side according to the designer's
specification).
All unused grommets must be blinded to maintain the
degree of protection.
The wiring and installation of the measuring & control
system elements must be performed by qualified profes
-
sionals authorized to perform wiring of the given type of
devices. The wiring must be performed in accordance with
the directives and standards of the country of installation,
and in accordance with the Installation and Operating
Instructions of individual pieces of equipment (frequency
converters, pressure and temperature sensors, etc).
Before putting the air-handling unit into operation, a wi-
ring inspection must be performed.
Conformity of the power supply voltage, frequency and
protection with the data on the type plate of the connected
block and cross-section of the connecting cables must be
checked before connecting the electrical equipment to the
power supply.
The connecting cables must be long enough to allow
free movement (e.g. when tightening the V-belts).
Properly fix all cables and keep minimum bending radi
-
uses.
If additional grommets are to be installed, avoid
installation of grommets and cables close to the doors,
access panels and connections of the air-handling unit's
blocks.
The cables must never obstruct routine operation and
servicing. Please respect the reserved servicing space.
Screw connections and grommets must not cause air
leakage.
Figure 22 –
cable wiring grommet design
The wiring grommet consists of a PG grommet,
distance piece and sealing
