Selection; Load Calculation - McQuay MDS030A Design & Installation Manual

Design & installation Guide For McQuay MDS Multi System
C H A P T E R
3
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Selection

3.1 Load Calculation

3.1.1 Planning and cooperation
McQuay recommends you to estimate and plan the following information before engineering.
°ˆ Based on the air conditional area function, calculate out the cooling/heating load (depending
on the temperature,humidity, and ventilation).
°ˆ Query related meteorologic information, especially the sun light, wind direction in winter and
summer, the ambient cooling/heating sources, and other external factors that may affect the
running of the units. Then decide the place and azimuth to place the units based on the
environmental factors favoring the normal running of the units. For the outdoor meteorologic
parameters of each city in China, see °∞Appendix 1 Outdoor meteorologic parameters of major
cities in China°± . However, the description about selection in this manual is only for your reference;
for actual engineering, please consult with a professional design institute or construction organ in
this area.
°ˆ Make the project schedule, plan the installation space of the unit, and adjust the engineering
associated with the constructional engineering and inside finishing.
°ˆ Through field survey, ascertain the size of the entrance for the air conditioner, the weight
capacity of the place to put or hang the equipment, the range of the auxiliary engineering, and
the location of the power supply.
°ˆ Check and verify the figures of the design. Confirm or decide the specifications and the unit model.
3.1.2 Cooling load calculation
°ˆ The cooling load of the air conditioning area is decided by the real-time maximum cooling load
or accumulated calculated cooling load of each room based on the area, height, and usage of
the room serviced. It is also affected by the additional cooling load caused by the ventilator
blower, the exhauster, and the air pipe system. In practice, it is calculated as follows:
Q = F q + F q + °≠ + F
total 1 1 2 2
Where,
F is the air conditioning area of each calculated unit. Its unit is m
1
q is the cooling load per unit area of each calculated unit. Its unit is W/m
1
Appendix 2 lists out the estimated indexes and design parameters for different buildings for
°ˆ
your reference.
3.1.3 Heating load calculation
°ˆ The heating load of the air conditioning system is closely related with the heat insulation performance
of the walls, doors and windows, and roof. It is also affected by the penetration of cool wind from
outdoors, open frequency of the outside door, and the use of the indoor appliances. It is calculated
basically in the same way as the cooling load. If the heating load per unit area of the
building qF is known (see Appendix 2), the heating load of the building is as follows:
Where,
F is the construction area. Its unit is m
q
n n
Q = Fq
F
2
2 .
2