SYSTEM

WHAT IS YOUR SYSTEM TO ACHIEVE:
Before starting to design a system, it is critical that you what your system is to achieve.
Often ,the objective is to provide a comfortable environment for the human occupants, but there are many other possible objectives: creating a suitable environment for regulating a hospital operating room, maintaining cold temperatures for frozen food storage; or maintaining temperature and humidity to preserve wood and fiber works of art. Whatever the situation, and humidity is important that the object criteria for system success are clearly identified at the start of the project, because different requirements need different design considerations.
Let us very briefly consider some specific design situation and the types of performance requirements for HVAC system.
Example 1:hospital operating room. This is a critical environment , often served by a dedicated air conditioning system .the design objectives include:
1 ,heating to avoid the patient from becoming too cold.
2,coling to prevent the members of operating team from becoming too hot.
3, control adjustment by the operating team for temperatures between 65 F AND 80 F.
4, humidifying, to avoid low humidity and the possibility of static electricity sparks.
5, dehumidifying, to minimize any possibility of mold and to minimize operating team discomfort.
6, cleaning the incoming air with very high efficiency filter , to remove any airborne organisms that could infect the patient.
7, ventilation , to remove airborne contaminants and to keep the theatre fresh.
8, providing steady air movement from ceiling supply air outlets down over the patient for exhaust near the floor, to minimize contamination of the operating site.
This situation requires a very comprehensive air conditioning system.
Example 2:frozen food storage. The ideal temperature for long storage varies : i.e ice cream requires temperature below—12 F and meat requires temperature below –5 F . the design challenge is to ensure that the temperature is accurately maintained and that the temperature is an even as possible through out the storage facility. Her, accurate cooling and good air movement are the prime issuse. although cooling and air movement are required , we refer to this system as a “freezer” not as an air conditioning are not controlled.