Warnings on the documentation
Intended use
AERMEC NCS series air handling units are built in accordance with recognized technical standards and safety regulations. Risks to the safety of the user or third parties, or even damage to the devices and other objects, may still occur in case of incorrect use. NCS represents the blend of experience, research and testing within the specific air machine sector.
The goal is to provide the customer with a highly industrialized flexible product with all the advantages that this choice provides in terms of quality and reliability. The NCS series adapts to all the specific needs of the system, both in terms of operation and
Conserving the documentation
Essential safety rules
Identification
Description of the unit
Modularity and sizes
Technical data
Description of components
- Panels
- Features of the pre-painted galvanised sheet steel
- Frame
- Base
- Roof
- Air inlet
The frame is constructed of UNI 6060 extruded aluminum alloy profiles joined together by fiberglass reinforced nylon angle pieces and self-tapping screws. The tubes that form the frame are completely closed and therefore the thermal bridges are reduced and the "bypass" of air around the various internal components of the system is eliminated. On request, the frame is also available in anodized aluminum UNI 6060 with or without thermal break.
The shape of the profiles and plates is shown in the drawing below, which shows a horizontal basic profile with a bottom plate and vertical uprights in between. On request this can be manufactured as standard with pre-painted 12/10 galvanized sheet with the same properties as described above for the sheet used for the panels. A silencer cannot be required: alternatively, the inlet can be an orifice, flange or blind plate into which a hole of the desired size must be made on site.
It is not necessary to require flaps: alternatively, the vents can be provided as simple flanged openings or blind plates, in which an opening of the desired size must be made on site.
Filtration
- Cell pre-filters
- Roll filters
- Bag filters
- Absolute filters
The efficiency of the roller filter is similar to that of synthetic filter cells (see table). Nevertheless, they have the great advantage of automatic renewal in accordance with an automatic signal (differential pressure switch) that allows rolling the dirty side of the roller and introducing the clean part into the air stream. The duration of the non-regenerative filter is closely related to the dustiness of the air, but it still allows long-term maintenance and is indicated by an optical or acoustic alarm signal that can also be remote from the unit (to the synoptic panel of the system).
The filter bags are attached to a special support frame with hermetic sealing systems to prevent any air circulation of untreated air, and. their extractability is ensured by a special inspection chamber upstream of the cells of suitable dimensions to allow access to maintenance engineers. Special versions of cell filter for specific applications in hospitals, chemical industry, etc. anti-contamination systems) can be studied by our technical sales department on specific request. ABSOLUTE FILTERS The absolute filters are general. The absolute filters are generally used where necessary to guarantee air purity and aseptic conditions at a high level. These types of filters are generally located in flow conditions, after the ventilation sections, and are preceded by progressive efficiency filtration systems (cell filters plus bag filters).
Special care is taken in the realization of the cell housing system to prevent any possibility of air bypass and to facilitate cell replacement during the maintenance phase.
Coils
- Heat exchange coils
- Water coils
- Direct expansion coils
- Electric coils
DIRECT EXPANSION SPOTS The geometrical characteristics are The geometrical characteristics are given in the following table. The electrically operated coils are often used for small thermal loads in small and medium-sized units mainly for summer after-heating when switching on the traditional hot water system is not possible or convenient. The thermal heads Dt refer to the nominal flow corresponding to a surface velocity on the coils of 2.5 m/s.
Humidification
Evaporator pack humidification
Steam humidification
Condensate drip trays
Drop eliminators
Ventilating sections
Fans
The pulleys can be fixed or variable for improved calibration of the fan speed in the system. Noise should be considered as one of the many polluting factors produced by modern technological machines. The transportability of the units from a dimensional point of view is highlighted in the Technical Data table (ch.5).
Avoid opening inspection hatches with the fan running, especially in the pressure section of the unit. The orientation of the fan must be chosen in accordance with the course of the first curve as shown in the compatibility diagram (Chapter 10). Install shut-off valves to isolate the coil from the rest of the circuit in case of special maintenance.
This type of humidification implies the connection of the water supply and drainage pipe. The supply and drain connections are located under the tray in the thickness of the base of the unit. The supply and drain connections are located under the tray in the thickness of the base of the unit. e) Evaporator pack moisture connection and pump.
The inlet and outlet connections are located under the tray in the thickness of the bottom of the unit. Check the position of the evaporator pack (F) and possible droplet eliminators (G), both of which are removable. If the latter is purchased as an additional equipment of the central air conditioning system, it is usually supplied installed on the side of the machine and already hydraulically connected (steam and condensation).
A typical connection of three-phase electric motors is shown in the following diagram (see the diagram inside the motor control panel or on the back of the control panel). Depending on the size of the central air handling unit, it may be necessary to disassemble the anti-splash nozzle to perform the installation.
Fans/central air handling unit compatibility table
Fan direction layout
Motors
Transmission
Recuperators
Empty sections
Silencers
Dimensions
- Fan assembly sections dimensions
- Mixing chamber with external dampers
- Filter sections
- Intake vents with external dampers
- Silencers
- Plenum with vacuum sections
- Humidification
- Recuperators
- Coils
Humidification with non-return water or pump (200 mm package) with droplet removers Steam humidification.
Handling
Packaging
Transport
Receipt of the material and checks
Storage on site
Installation
- Safety warnings and installation regulations
- Lifting and positioning
- Minimum technical clearances
- Joining the sections
LIFTING AND PLACING The NCS series units are designed The NCS series units are designed to be lifted with a hook from below. For units equipped with a continuous base and angled legs, insert the appropriate tube to safely lift the unit into the yellow and black marked holes (labeled A and B in the figure below). For units without legs or continuous base supports, brackets are provided that are attached to the frame (marked with C in the figure) and must be removed after moving.
Another option is to do the positioning by sliding the center on the tubes that act as rollers. Fan motor assemblies are mounted on anti-vibration mounts; however, it is recommended to insert an anti-vibration pad between the base of the unit and the floor. When installing a central air conditioner, the space required for regular and emergency maintenance must be taken into account.
If the unit is to be placed next to a wall, leave a corridor equal to the width of the unit plus 100 mm on the inspection and header side (fig. B). JOINING IN SECTIONS Units supplied in different sections Units supplied in different sections must be assembled according to the design attached to the unit, using the materials supplied con-.
Connections
- Aeraulic connections
- Hydraulic connections
- Electrical wiring
- Electric pump connection
- Condensate drain
- Electric coils connection
- Earth
- Filter cells mounting
Adjust (before bends, branches, etc.) the delivery channel with a straight section with a length at least 2.5 times shorter than the shortest side of the channel, to avoid a drop in channel performance levels;. Where flange connections are required, a threaded flange should be used to allow coil removal which involves releasing the heads from the side panel of the unit. The pipe route must be designed so that it does not create obstacles in the case of removing the coils and does not interfere with the control door of the unit.
Avoid using force that could damage the coil during the screwing operations of the system's hydraulic circuit coil assemblies. See the tables on pages 15 and 16 of this manual for the size of the heat exchanger coils and the dimensions of the header pipes. Make sure the coil change is done in reverse; .. the cooling circuit must be equipped with all regulation and safety devices to avoid damage to the coil; .. the pipes must be sized and fitted with suitable traps to allow the movement of oil to ensure lubrication of the compressor; .. be aware of the vibrations transmitted to the direct expansion coil, which can lead to breakage of the welds.
For coil filter connections and power coil connections, refer to the wiring diagram attached to each individual coil. Below you will find the rules to be followed for the dimensioning and version of siphons in the case of a vacuum or pressure tank. For electrical connection, see the master wiring diagram on the side or the one attached to each individual coil.
Start-up
Fans
If absorption is excessive, it is likely that the air distribution pressure drops are overestimated and the capacity is excessive. In this case, set an additional resistance with a calibration damper or preferably reduce the fan rotation speed by changing transmission. In central air handling units with variable pitch pulley, the speed is changed by changing the pitch (B in figure 16.1.1).
Since there is a rapid drop in tension during the break-in period of new transmissions, the new belt will need to be tightened so that the force F to obtain the arrow f is 1.3 times the value of F" indicated in the table.
Heat exchange coils
Electric pumps
Filters
Humidification
Maintenance
