Boreas Technologies Air Handling Unit Guide

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BOREAS 5TH GENERATİON AIR HANDLING UNIT
İnstallation
Commissioning
Maintenance Manual

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CONTENTS
FİGURES......................................................................................................................................................... 5
TABLES ........................................................................................................................................................... 6
1 General Considerations......................................................................................................................... 7
1.1 Use ın Accordance wıth Instructions............................................................................................. 7
1.2 Plant Room .................................................................................................................................... 7
1.3 Transport and Storage................................................................................................................... 7
1.4 Installation..................................................................................................................................... 8
1.5 Before Commissioning................................................................................................................... 8
1.6 Freeze Protection .......................................................................................................................... 9
2 Safety Warnings..................................................................................................................................... 9
3 Emergency Measures .......................................................................................................................... 10
4 Maintenance and Cleaning Measures................................................................................................. 10
4.1 Maintenance Intervals................................................................................................................. 10
4.1.1 Filter..................................................................................................................................... 10
4.1.2 Heat Exchangers .................................................................................................................. 11
4.1.3 Fans...................................................................................................................................... 11
4.1.4 Automation or Power Panel................................................................................................ 12
4.1.5 Cleaning Inside the Unit ...................................................................................................... 12
4.1.6 Draining System................................................................................................................... 12
4.1.7 Droplet Eliminator............................................................................................................... 12
5 Delivery................................................................................................................................................ 13
5.1 Unloading the Unit From the Truck and Handling ...................................................................... 13
5.1.1 Unloading the Unit From the Truck and Carrying the Unit Using a Winch ......................... 13
5.1.2 Unloading the Unit From the Truck and Carrying the Unit Using a Forklift ........................ 14
6 Assembly and Installation.................................................................................................................... 15
6.1 Installation of the Unit ................................................................................................................ 15
6.2 Section Connections ın Unit ........................................................................................................ 16
6.3 Duct Connection.......................................................................................................................... 18
6.4 Heat Exchanger Connection ........................................................................................................ 19
6.4.1 Water Heating and Cooling Heat Exchanger....................................................................... 19
6.4.2 DX Heat Exchanger (Dx-Direct Expansion Heat Exchanger) ................................................ 20

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6.5 Connection of Condensate Outlet And Drainage Line ................................................................ 20
6.6 Electrical Connection................................................................................................................... 21
6.6.1 Air Handling Unit without Panel.......................................................................................... 21
6.6.2 Air Handling Unit with Panel ............................................................................................... 22
6.7 Rotary Heat Recovery Unit.......................................................................................................... 22
6.8 Installation Connection for Evaporative Humidifier Section....................................................... 22
6.9 Installation Connection for High Pressure Humidifier Section.................................................... 23
6.10 Steam Humıdıfıer Section Connectıon ........................................................................................ 23
6.10.1 Ready Steam Systems.......................................................................................................... 23
6.10.2 Packaged Steam Humidifier Systems .................................................................................. 23
6.11 Final cleaning............................................................................................................................... 24
6.12 Access Door Adjustment ............................................................................................................. 24
7 Commissioning and Maintenance....................................................................................................... 25
7.1 Fans and Motors.......................................................................................................................... 25
7.1.1 Initial Start-up...................................................................................................................... 25
7.1.2 Maintenance........................................................................................................................ 27
7.2 Air Filters ..................................................................................................................................... 28
7.2.1 Initial Start-up...................................................................................................................... 29
7.2.2 Maintenance........................................................................................................................ 29
7.3 Heating Water Coil ...................................................................................................................... 30
7.3.1 Initial Start-up...................................................................................................................... 30
7.3.2 Maintenance........................................................................................................................ 30
7.4 Cooling Water Coil....................................................................................................................... 31
7.4.1 Initial Start-up...................................................................................................................... 31
7.4.2 Maintenance........................................................................................................................ 31
7.5 Direct Expansion Cooling Coil And Cooling System..................................................................... 32
7.5.1 Initial Start-up...................................................................................................................... 32
7.5.2 Maintenance........................................................................................................................ 33
7.6 The Draining System.................................................................................................................... 33
7.6.1 Commissioning .................................................................................................................... 33
7.6.2 Maintenance........................................................................................................................ 34
7.7 Drop Eliminator ........................................................................................................................... 34
7.7.1 Initial Start-up...................................................................................................................... 34

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7.7.2 Maintenance........................................................................................................................ 35
7.8 Heat Pipe Heat recovery Heat Exchanger ................................................................................... 35
7.8.1 Initial Start-up...................................................................................................................... 35
7.8.2 Maintenance........................................................................................................................ 35
7.9 Rotary Type Heat Recovery Unit Heat Exchanger....................................................................... 35
7.9.1 Initial Start-up...................................................................................................................... 35
7.9.2 Maintenance........................................................................................................................ 36
7.10 Plate Type Heat Recovery Unit Heat Exchanger.......................................................................... 37
7.10.1 Initial Start-up...................................................................................................................... 37
7.10.2 Maintenance........................................................................................................................ 37
7.11 Run Around Type Heat Recovery Heat Exchanger ...................................................................... 37
7.11.1 Initial Start-up...................................................................................................................... 37
7.11.2 Maintenance........................................................................................................................ 38
7.12 Evaporative Humidifier System ................................................................................................... 38
7.12.1 Initial Start-up...................................................................................................................... 39
7.12.2 Maintenance........................................................................................................................ 39
7.13 High Pressure Humidifier System................................................................................................ 39
7.13.1 Initial Start-up...................................................................................................................... 39
7.13.2 Maintenance........................................................................................................................ 40
7.14 Steam Humidifier System............................................................................................................ 40
7.14.1 Initial Start-up
...................................................................................................................... 40
7.14.2 Maintenance........................................................................................................................ 40
7.15 The Electrical Heater System....................................................................................................... 41
7.15.1 Initial Start-up...................................................................................................................... 41
7.15.2 Maintenance........................................................................................................................ 41
7.16 Silencer System............................................................................................................................ 42
7.16.1 Initial Start-up...................................................................................................................... 42
7.16.2 Maintenance........................................................................................................................ 42
8 Troubleshootıng .................................................................................................................................. 43
9 Commissioning Request Form............................................................................................................. 44

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FİGURES
Figure 1 Correct Stacking of Sections............................................................................................................8
Figure 2 Incorrect Stacking of Sections.........................................................................................................8
Figure 3 Correct Carriage with Forklift .........................................................................................................13
Figure 4 Incorrect Carriage with Forklift ......................................................................................................14
Figure 5 Levelling the Air Handling Unit Using Chucks................................................................................14
Figure 6 Service Clearance…………………………………………………………………………………………………………………...…15
Figure 7 Service Clearance………………………………………………………………………………………………………..…………....16
Figure 8. Section Connection Labels................................................…….…….……………………………..…………....16
Figure 9 Sealing of Section Connection................................................………………..………….........................16
Figure 10 Mounting the Section Connecting Piece .....................................................................................17
Figure 11 Sealing of Duct Connection .........................................................................................................17
Figure 12 Method of Duct Connection........................................................................................................18
Figure 13 Direction of Connection of Exchanger Pipe................................................................................19
Figure 14 Coil Connection ...........................................................................................................................19
Figure 15 Installation of the Drainage Line .................................................................................................20
Figure 16 Electrical Connection Terminal....................................................................................................21
Figure 17 Installation Connections for Evaporative Humidifier ..................................................................21
Figure 18 Steam Installation Connection ....................................................................................................22
Figure 19 Steam Humidifier Connection ....................................................................................................23
Figure 20 Hinge Adjustment........................................................................................................................24
Figure 21 Fan Suction Funnel Measurement…………....................................................................................24
Figure 22 Direction of Installation of Droplet Eliminator............................................................................25
Figure 23 Installation of the Run Around Type Heat Recovery Unit ...........................................................26
Figure 24 Silencer Section ...........................................................................................................................33

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TABLES
Table 1 Maintenance Check-list Spare Part Delivery / Customer Services / Repairs.................................. 12
Table 2 List of Spare Parts ........................................................................................................................... 13
Table 3 Prooperties of Water to be Used in Humidification System .......................................................... 23
Table 4 Wheel Tension Setting Table……………………. ................................................................................... 25
Table 5 Vibration Reference Values ............................................................................................................ 27
Table 6 Filter Replacement Pressure Values According to EN 13053 ......................................................... 29

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1GENERAL CONSIDERATIONS
The BOREAS Air Handling Unit installation, commissioning, and maintenance manual was
prepared to provide extensive information on the unit’s technical specifications, transport,
installation, commissioning, and operational maintenance. Anyone who is to work on the unit should
read this manual in advance and carefully follow the instructions given. BOREAS A.Ş. does not hold any
responsibility for malfunctions to the unit that are caused by a failure to follow the warnings specified in
this manual. In the event that users make any modifications, alterations on the unit within the
knowledge and approvalof BOREAS A.Ş. during the warranty period, the warranty scope shall be
deemed null and void.
1.1 USE IN ACCORDANCE WITH INSTRUCTIONS
The BOREAS Air Handling Unit manufactured by BOREAS A.Ş. is used for the ventilation of spaces;
filtration, heating-cooling of air, heat recovery, humidification and dehumidification depending on design
specifications and the section types selected. BOREAS A.Ş. does not permit the use and operation of its
Air Handling Unit for other purposes than that listed. Any malfunctions that arise from use for purposes
other than that listed above are outside the scope of the warranty. Some examples are: using air
handling unit sections as shelter, using air handling unit framework as scaffolding in construction sites,
and using air handling unit sections as storage areas.
1.2 PLANT ROOM
Sufficient maintenance spaces and clearances should be left in the area where the Air Handling Unit will
be installed, for operation and service actions. It is recommended that the floor is smooth and easily
cleaned, to prevent the accumulation of dirt and dust. The space should be illuminated, ventilated,
humidity and temperature controlled. An area equal to the depth of the heat exchanger (Heating-
Cooling Exchanger, Plate-Rotary Heat Recovery Units) should be left as a minimum in sections where
heat exchangers are located, for maintenance work. (See 6.1 Unit Installation).
1.3 TRANSPORT AND STORAGE
The BOREAS Air Handling Unit is prepared for shipping in sections, and by applying appropriate
packaging and transport methods on each section. To facilitate easy horizontal and vertical handling of
sections, section feet have forklift transport holes and winch handling rings as standard. The use of these
is recommended during handling. Damages that may arise otherwise fall outside the scope of the
warranty. If the air handling unit must be stored for longer than 3 months, the following procedures
must be followed:
•The packaging of units should be removed in order to facilitate free ventilation with the purpose
of eliminating moisture from condensation inside the packaging, and the units should be
repackaged after a period of 1-2 hours.

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•Fans included within the fan and aspirator sections should be manually rotated once a month. If
it includes a belt and wheel mechanism, the belt should be left loose.
•If the air handling unit includes rotary type heat recovery, the rotor should be manually rotated
once a month.
•The dampers should be manually moved once a month.
•The service doors of chambers should be opened and closed once a month to avoid damage to
seals.
•If the air handling unit includes a power or automation panel the board cover should be opened
to allow free ventilation.
•Care should be taken to ensure that the plugs on the collector intakes and discharges of heat
exchangers are in place. If the plug is absent for any reason, the plug should be procured by
contacting the BOREAS A.Ş. Technical Service
•Storage conditions should be ensured for all sections, to protect sections from outdoor
conditions. If storage in outdoor space is unavoidable, the unit sections must be subjected to
additional packaging to prevent direct impact of outdoor conditions.
•Air handling unit sections should not be stacked. If stacking is unavoidable, each section should
be placed within am individual cage or case.
Figure 2 Incorrect Stacking of Sections
1.4 INSTALLATION
The sections that make up theBOREAS Air Handling Unit are manufactured and shipped separately.
These sections are assembled in the manner specified in this manual, making up the air handling unit.
After the section assembly is complete, the cable installation must alsobe completed.
1.5 BEFORE COMMISSIONING
The BOREAS Air Handling Unit should be commissioned after all installation procedures included in this
manual have been completed and the unit has been checked. It is suggested that the final checks and
Figure 1 Correct Stacking of Sections

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commissioning be carried out by the BOREAS A.Ş. Technical Service or its authorized installation teams. It
is suggested that the maintenance and repair circuit breaker be installed on the unit’s power supply line,
and in close proximity to the unit.
1.6 FREEZE PROTECTION
It is recommended that the unit not be brought offline at low temperatures, to avoid freezing of the
unit’s moveable parts. The use of a freeze-free thermostat with automatic reset for the water heating
exchanger is recommended. This enables freeze protection during operation. If the unit must be brought
offline, it is strongly recommended that the water within the water exchangers be purged.
2SAFETY WARNINGS
Failure to obey the following warnings and relevant national and international safety instructions
may cause serious work accidents, human injuries, and even deaths.
If the unit is to be serviced, this must be carried out by authorized teams, and the following precautions
must be taken. The unit should not be serviced otherwise.
•All electrical connections to the unit must be cut.
•The necessary precautions must be taken and the unit locked against resuming during service.
•Care should be taken to ensure that the unit’s moving parts such as fan, rotary heat recovery
unit, compressor, pump, etc. have been stopped and that they will not resume during servicing.
•In cooling and heating sections where a high temperature differential can occur, the expected
temperature difference between the inside of the section and the ambient temperature should
be around 10°C.
•The service personnel must wear protective equipment.
The following warnings must be followed when restarting the unit after the completion of the service.
•Care must be taken to ensure that there is no living creature within the unit.
•Care must be taken to ensure that no service equipment has been forgotten within the unit. Care
must also be taken to ensure that there are no parts that had not been fixed in place after being
removed.
•Care must be taken to ensure that door locks are closed particularly on positive pressure fan
sections, and that there are no people near the door during initial start-up.
•If air dampers are manually controlled, care must be taken to ensure that they are in their on
position.
All procedures specified above must be carried out by authorized BOREAS A.Ş. personnel or by specialist
personnel approved by BOREAS A.Ş.

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3EMERGENCY MEASURES
In emergencies caused by the unit or by environmental conditions, exact adherence to the
following warnings is of utmost importance.
•If smoke is issuing from the unit, the unit’s main power supply must be disconnected
immediately.
•If a mechanical friction sound is heard during the unit’s operation, the unit’s main power supply
must be disconnected and the BOREAS A.Ş. Technical Service informed.”
•If dust or unidentified particles issue from the unit’s discharge line to the space, the unit must be
stopped and its filters must be serviced urgently. The unit must not be restarted without
replacing filters.
•If there is water overflow from the unit, the unit’s cooling circuit must be shut off, and care must
be taken to ensure that the drainage line is clear.
4MAINTENANCE AND CLEANING MEASURES
4.1 MAINTENANCE INTERVALS
The BOREAS Air Handling Unit requires regular maintenance for uninterrupted and long service. The
unit’s parts which require periodic maintenance are the following:
4.1.1 Filter
Filters can be used optionally at the fresh air intake and return air intakes of the air handling unit. As
these filters clean the air, they have a direct impact on the cleanliness and consequently the efficiency of
the equipment within the unit. The use of differential pressure switches is recommended for checking
the dirtiness of these filters. The recommended filter replacement values according to the EN 13053
standard are as follows:
•150 Pa for panel filters (G2-3-4)
•200 Pa for bag filters (M5-6,F7)
•300 Pa for bag filters (F8-9)
Washing and subsequent reuse of filters is not recommended. While they may appear to conform
visually and in terms of pressure loss, the filter pores will be damaged by the washing, and will not
perform their filtration function.
Failure to replace filters at the periods specified above will lead to the following
•The problem of insufficient air flow from the unit will occur due to the extra air side pressure
drop that will occur at the air side of the filter.

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•Sufficient filtration will not occur, due to clogging of filter pores, which will cause a deterioration
in the conditions of comfort.
•If the accumulation on the surface reaches the point where the filter is clogged, the passage of
air through the filter will not be possible. In this case, vacuum will be formed in the sections that
come after the filter, and if the vacuum level exceeds the limits specified in En 1886 tests, there
will be risk of caving in unit panels.
4.1.2 Heat Exchangers
The following types of heat exchangers can be used optionally in the BOREAS Air Handling Unit:
•Direct Expansion Refrigerant Heat Exchanger
•Water Heating – Cooling Heat Exchanger
•Plate Type Heat Recovery Unit Heat Exchanger
•Rotary Type Heat Recovery Unit Heat Exchanger
•Heat Pipe Type Heat Recovery Unit Heat Exchanger
•Run Around Type Heat Recovery Unit Heat Exchanger
There is a possibility of occlusion due to the accumulation of dust between the fins of heat exchangers.
Periodic cleaning of heat exchanger surfaces with water or air every 3 months is recommended. The
following problems may occur unless heat exchanger surfaces are cleaned:
•Air side pressure drop values of heat exchangers will exceed design specifications due to
clogging. If this value exceeds the limit of the fan or motor, sufficient air flow can not be
achieved. This will cause a deterioration in the conditions of comfort as well as a drop in the
unit’s efficiency.
•Dust particles accumulating on the heat exchanger create a resistance between the air and the
heat transfer surface area and negatively affect heat transfer efficiency. This will lead to a drop
in unit efficiency, and a failure to achieve the desired conditions in the environment.
4.1.3 Fans
The following types of fans can be used optionally in the BOREAS Air Handling Unit:
•Forward Curved Dense Blade Fans
•Backward Curved Rare Blade Fans
•Direct Coupled Plug Fans
•Direct Coupled EC Plug Fans
•Fan Surface (Multiple Fan Application in Air Flow Cross section).

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An overall cleaning of fan wheels every 4 months is recommended to avoid the accumulation of dirt and
dust. A mechanical friction test should also be performed during operation. In belt and wheel fans, belt
tension should be checked and wheel adjustment performed after initial start-up and at periodical
maintenance intervals.
4.1.4 Automation or Power Panel
The automation system is offered as an option in the BOREAS Air Handling Unit. Since it contains all
power and control equipment, the automation panel is sensitive to dust and ambient temperature.
Therefore the panel should be checked every 2 months for dust accumulation and the correct
temperature. The panels are equipped with filtered ventilation fans as a standard. Replacing these filters
every 2 months is critical in terms of balancing the temperature within the panel.
4.1.5 Cleaning Inside the Unit
The smooth interior surface of the BOREAS Air Handling Unit makes cleaning inside the unit very easy. It
should be cleaned every 3 months to avoid accumulation of dirt and dust, using only alcohol based
disinfectants approved for the country in question. The cleaning interval may change by ± 1 month
depending on the level of pollution of the air where the unit is used.
4.1.6 Draining System
A high level of condensation may occur in cooling sections, depending on the conditions of the
environment where the air handling unit will operate. The water thus formed must be quickly and safely
transferred from the unit to the draining system. A clogging in this system will lead to accumulation of
water within the unit, and cause the unit to malfunction by damaging its internal and electronic
components. Therefore draining outlets should be checked for cleanness every month.
4.1.7 Droplet Eliminator
A drop eliminator is used after the cooling exchanger as standard equipment, to prevent water droplets
formed by water vapour condensing on heat exchanger surfaces in cooling sections from being detached
by the motion of air and carried over to other sections. The drop eliminator should be checked and
cleaned every 3 months, and protected against accumulated dust and dirt. The droplet eliminator should
be installed by paying attention to the flow direction label on the droplet eliminator.
Table 1 Maintenance Check-list Spare Part Delivery / Customer Services / Repairs
Equipment
1 Month
2 Months
3 Months
4 Months
Filter
x
Heat Exchangers
x
Fans
x
Automation Panel
x
Unit Interior
x
Draining System
x
Drop Eliminator
x

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4.2 SPARE PART DELİVERY /CUSTOMER SERVİCES /REPAİRS
Changes that need to be made on the unit must be made only by authorized BOREAS A.Ş. personnel or
by specialist personnel approved by BOREAS A.Ş. for the unit. It is recommended that the spare parts
used be the same brand and model as used in the unit. The unit operation instructions contained in this
document must be followed in full, for commissioning the unit following spare part replacement and
repair. The list of recommended spare parts is the following.
Sequence
Number
Material Name
1
G4 Panel Filter
2
F5-F9 Bag Filter
3
Electrical Motor
4
Belt
5
Damper Motor
6
Fan Bearing
7
Electrical Control Panel
8
Service Door Seal
Table 2 List of Spare Parts
5DELIVERY
The unit must be visually inspected and checked for any visible damage before accepting delivery
of the unit. The unit is delivered shrink wrapped with all equipment mounted, in the form of a
finished section as in technical selection printouts. If damage is observed during the visual inspection,
immediately note it on the waybill and make sure the waybill is approved by the driver. Take an image of
the damage and inform the BOREAS A.Ş. Logistics Department.
5.1 UNLOADING THE UNIT FROM THE TRUCK AND HANDLING
The BOREAS Air Handling Unit is equipped with handling rings for connecting winch rings and transport
holes for carriage by forklift.
Persons should not stand below suspended loads during the carriage of Air Handling Unit
sections.
5.1.1 Unloading the Unit From the Truck and Carrying the Unit Using a Winch
The slings, ropes, and chains that will be used while unloading the unit from the transport truck and
carrying the unit must be in compliance with the Lifting Operations and Lifting Equipment Regulations.
Tie the haulage ropes on the carrying rings found on the corners of the unit legs and make sure they are
tight. The center of weight of the unit along its width is on roughly the middle point. The use of rope
support apparatus that is larger than the width of the unit is recommended to prevent the ropes from
damaging the unit.

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5.1.2 Unloading the Unit From the Truck and Carrying the Unit Using a Forklift
Make sure that the forklift forks pass through the forklift holes found on the unit legs and under
the entire bottom section. Otherwise, the drainage pan and bottom covering panels located on
the underside of the unit can be damaged. Forklift transport holes are found as a standard on both sides
of unit legs. These holes are positioned by reference to the unit’s centre of mass.
Figure 4 Incorrect Carriage with Forklift
Figure 3 Correct Carriage with Forklift

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6ASSEMBLY AND INSTALLATION
6.1 INSTALLATION OF THE UNIT
The BOREAS Air Handling Unit must not be used as any structural part of the structure, in the
section of the machinery room where it will be installed. If the unit is used in a way that is
assumes functions such as the roof, wall, and load bearing system of the area where it is located,
the product warranty becomes void.
The BOREAS Air Handling Unit is manufactured in the form of sections, depending on project selections.
The air handling unit is formed by mounting these sections at connecting holes. Therefore, it is of the
highest importance for the floor on which the unit will be positioned and assembled be flat and level. If
the floor can not be corrected, the unit should be levelled using appropriate balancing equipment (chuck
etc.) (Figure 3).
Figure 5 Levelling the Air Handling Unit Using Chucks
Care should be taken to ensure that adequate clearances are left around the unit, to facilitate servicing
the Air Handling Unit on site. These clearances are:
•The width of the unit + 30 cm for the service side
•A minimum of 50 cm for the side opposite the service side
•A minimum of 70 cm for the top side of the unit.
Observing these clearances is very important with respect to convenience of service.

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Figure 8. Section Connection Labels
Figure 6 Service Clearance Figure 7 Service Clearance
It will be beneficial to use rubber based vibration absorbing materials between the unit base and the
floor, before assembling the Air Handling Unit. One piece of material should be placed at each corner of
each section. We recommend that you contact the BOREAS A.Ş. Technical Department since the
thicknesses of rubber material will vary depending on unit specifications.
6.2 SECTION CONNECTIONS IN UNIT
The connecting equipment needed for section to unit connection are delivered pre-mounted on the
sections. As explained in Figure 5, after the unit has been precisely levelled the hole axes of section
connection pieces will align with one another. Connecting holes found on section connection pieces have
been designed as horizontal or vertical almond holes. This increases mounting tolerance. Before the
sections are assembled, hermetic seals (3x30 mm EPDM Single Sided Adhesive Seal) should be applied to
connecting surfaces of sections, after cleaning the surfaces of oil and dirt. Application of this seal is very
important in terms of air leakage.
•Care should be taken to ensure that the floor on which the air handling unit will be installed is
level.
•Care should be taken to ensure that the floor on which the air handling unit will be installed is
clean, this area will be difficult to clean after the installation.
•There are number tags on each section for information purposes, which indicate the sections
that come before and after it. The sections must be arranged according to these numbers.

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•Make sure that the clearances specified in Figure 6-7 be left to facilitate service work around the
air handling unit.
•3x30 mm EPDM seal must be applied to sections’ profile surfaces as shown in Figure 9. Make
sure profile surfaces have been cleaned of oil and dust before applying the seal.
Figure 9 Sealing of Section Connection
•After the sealing process, the hole axes of section connection pieces must be aligned and the
sections connected using M8 nut and bolt.
Figure 10 Mounting the Section Connecting Piece

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6.3 DUCT CONNECTION
Pipe bends for connection are found for duct connections on dampers and flanges. It is important
for connections to be made over these bends. Before making the connection, 3x30 mm EPDM
seal must be applied to these bends in order to prevent air leaks.
•Dampers and flanges must not be made to bear the load of ducts under any conditions. Instead,
the duct weight should be born by fixed supports on the ceiling or floor. (Figure 12)
•Duct connections with sharp turns should not be used on unit joints. A straight line should be
used for a certain distance L, which should be followed by a bend, as in Figure 11. This distance L
can be taken as 2.5-3 times the duct cross section.
•Sealing must be used between the duct and damper and flange connecting surfaces. (Figure 11)
Figure 11 Sealing of Duct Connection

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Figure 12 Method of Duct Connection
6.4 HEAT EXCHANGER CONNECTION
6.4.1 Water Heating and Cooling Heat Exchanger
The air handling unit may come with a water heating or water cooling heat exchanger depending on
project selections. These need to be connected to the water installation for their water supply. The
water inlet and outlet lines of heating or cooling heat exchangers have been labelled on the unit, with
the water inlet on the air discharge side (Figure 13), and it is important for the assembly to be made
according to these markings. Incorrect connections will lead to loss of capacity in the heat exchanger.
Figure 13 Direction of Connection of Exchanger Pipe
Recommendations:
•If a motor driven valve is to be used for flow control, it is recommended that the installation be
carried out by the manufacturer of the motor driven valve, and according to installation
warnings.
•The maximum recommended difference between the pipe diameter of the selected motor
driven van and the diameter of the heat exchanger collector pipe is one module.
•The use of pipe flanges is recommended to connect heat exchangers to the water supply
installation. (Figure 14)