Design Of Air System - McQuay MDS030AR Applications Manual

Design & installation Guide For McQuay MDS Multi System
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3.4 Design of Air System

The air cooled pipeline unit is an important and complex part of the air system. The air system must
be designed in compliance with Design Code for Heating, Ventilation and Air Conditioning and
Code of Design on Building Fire Protection.
The air pipe diameter, processing, air outlet, muffling static pressure box, fire protection valve,
insulation and indoor airflow layout must be designed professionally and well implemented, so as
to achieve an ideal effect of comfortableness and energy saving. The following information or data
is a reference for users to design.
3.4.1 Design of the Air Flow, Air Pipe and Air Outlet
The air should be supplied to the indoor space in a volume corresponding to the load at a most
comfortable speed, so as to achieve comfortable air conditioning.
Air outlet design & calculation
Air supply is to supply cool/hot air to a room or specified air conditioning area, and to mix
the indoor air and supply airflow to the room temperature.
The direction and guiding force of the air outlet vary with the outlet shape and type. Select
according to the purpose.
Determine the volume and arrival distance of air supply from a single outlet according to
the para-meters in the product catalog. Select the air outlet and return outlet type that
matches the ceiling pattern according to the room shape. In addition, the relationship
between air speed and noise should be considered to determine the outlet air speed.
Annex 3 is for your reference only.
Air flow pattern
No. Return air flow pattern
Side air supply
1
upper air return
The room with high floor height
Upper air supply
2
upper air return and only for cooling in Summer
Side air supply
3
The room with low floor height
side air return
Air outlet selection
In the designing of the air-flow pattern, determine the type of the air outlet according to air
conditioning accuracy, air-flow type, air outlet installation position and construction fittment art.
Common types of the air outlet
Side air outlet
The shutter air outlet is generally used. The shutter can be louver shutter to adjust the air flow and
direction. Besides, grille air outlet and slotted air outlet are also used. These two outlets can well
match with the construction decoration.
Air diffuser
The air diffuser is the air outlet installed in the ceiling, supplying air flow from top to bottom.
Orifice plate air outlet
The orifice plate air outlet features even air supply and fast air flow attenuation. It applies to the
room where even air flow and little temperature difference are needed.
Jet air outlet
The jet air outlet features long range and low noise. It applies to large public buildings, such as
gymnasium and cinema.
Whirl air outlet
The whirl air outlet features good mixture of supplied air and indoor air and fast-speed attenuation.
It applies to the floor air supply in the computer room.
Range
Staffs are in the return air flow area, need for little or no space, and the
The room with low floor
air vent can be adjusted freely. But, the exposed ceiling in the room
height or large depth
has two difference heights or there are two exposed ceilings.
The fan coil of air pipe in the exposed ceiling makes the fittment
easy. But, higher floor height is required and certain exposed ceiling
space is occupied.
Staffs are in the return air flow area, the fan coil of the unit does not
occupy the indoor space in the corridor, and the air vent can be
adjusted freely.But, short-flow may occur easily.
Advantages and disadvantages