Article table of contents:
1. What is HVAC? Construction and working principle of HVAC system
1.1 Definition of HVAC
1.2 Structure and working principle of HVAC system
1.3 Functions of HVAC
2. HVAC System in Clean Room
3. HVAC system design
1. What is HVAC? Construction and working principle of HVAC system
1.1 Definition of HVAC
HVAC stands for Heating, Ventilating, and Air Conditioning.
An HVAC control system is a system for controlling temperature, humidity and air quality in an indoor or vehicle space. Providing an acceptable level of indoor air quality and thermal comfort is a requirement for an HVAC system. The purpose of the HVAC system is to create a space with the highest temperature, quality and humidity. HVAC systems are used in both industrial and commercial and residential applications.
1.2 Construction and working principle of HVAC system
1.2.1 Construction of HVAC
HEATING SYSTEM
Used to generate heat (warmth) in buildings or commercial centers, usually this is done by a central heating system.
The general structure of the heating system includes:
Boilers
Heater or heat pump: Used to heat water, steam or possibly air in a central location such as a furnace room in a house, a mechanical room in a large building. The hot steam can be transferred by convection, conduction or radiation.
VENTILATION SYSTEM (VENTILATION)
The task of this system will be to change or replace the airflow in any space to control temperature or to remove any combination of moisture, odor, smoke, heat, dust, or bacteria in the air either CO2 and supplemented with Oxygen.
In many cases, ventilation also includes the exchange of air with the outside as well as the circulation of air in the building. Ventilation system is considered as one of the very important factors to maintain the quality of air inside each area in the buildings.
AIR CONDITIONING
Mission: Provide pre-set required airflow and humidity for the whole or part of the building. Normally, buildings with air conditioning installed often have closed doors, opening the windows will reduce the cooling efficiency from the air conditioning system.
Air conditioning and refrigeration are typically created by removing heat from within the system. The temperature of the air can be removed by radiation, convection or conduction through a refrigerating device. Several media help to transmit cold such as water, air, ice, chemicals or collectively called refrigerants. These refrigerants are used in heat pump systems, in which the compressor is used to control the cooling cycle by thermodynamics, or in a refrigeration system using pumps to operate the refrigerant. transfer a refrigerant (usually water or a glycol mixture). Ventilation system in HVAC is considered as one of the very important factors to maintain the quality of the air inside each area in the buildings.
1.2.2 Working principle of HVAC system
The air handling unit (AHU) functions to supply air and control the quality of air brought in from the outside. Excessive moisture, odors and environmental contaminants when introduced are diluted or replaced with air from outside.
Ventilation methods:
Natural method: A method of circulating air outside without the use of exhaust fans, or other mechanical systems. The air is passed through the small vent window. Some buildings use the “stack effect” to get the best amount of outside air in. This method takes very little energy, so sometimes the air quality may not be as expected.
+ Artificial method (Ventilation by exhaust fan): This method uses exhaust fans, ducts, controllers to control the quality of air circulating in
building.