Heating, ventilation, and air conditioning (HVAC) system is intended to meet the environmental requirements of occupant comfort.
HVAC systems are increasingly used in a variety of buildings, including industrial, commercial, residential, and institutional structures. HVAC systems provide thermal comfort to building occupants by adjusting and changing outdoor air conditions to the desired conditions.
Depending on the weather, outdoor air is drawn into buildings and heated or cooled before being distributed into occupied spaces, after which it is exhausted to the outside air or reused in the system. The climate, the age of the building, the individual preferences of the building’s owner and a project designer, the project budget, and the architectural design of the buildings will all influence the selection of HVAC systems in a given building.
Classification Of HVAC Systems
HVAC systems can be classified based on the processes required and the distribution process. The required processes include the heating, cooling, and ventilation processes. Other processes can be added such as humidification and dehumidification process.
Heating systems, air-conditioning systems, ventilation fans, and dehumidifiers are examples of HVAC equipment that can be used to accomplish these processes. HVAC systems rely on the distribution system to deliver the necessary amount of air while maintaining the desired environmental conditions. The distribution system varies primarily based on the refrigerant type and the method of delivery, such as air handling equipment, fan coils, air ducts, and water pipes.
Selection of HVAC system
The selection of a system is influenced by three major factors: the building configuration, the climate conditions, and the owner’s desire. The design engineer is in charge of considering various systems and recommending multiple systems to meet the goal and satisfy the building’s owner. Climate change (e.g., temperature, humidity, and space pressure), building capacity, spatial requirements, cost (capital cost, operating cost, and maintenance cost), life cycle analysis, and reliability and flexibility are some criteria that can be considered.
However, there are some constraints that must be determined when selecting a system. These constraints include standard capacity, building configuration, available space, construction budget, available utility source, and heating and cooling building loads.
The fundamental components of an HVAC system
The following are the basic components or equipment of an HVAC system that delivers conditioned air to satisfy the thermal comfort of occupants and to achieve indoor air quality:
- Plenum with mixed air and outdoor air control
- Air purifier
- Exhaust or relief fans, as well as an air outlet
- Air intake from the outside
- Terminal equipment
- System of return air
- Coils for heating and cooling
- Heating or cooling system that is self-contained
- The cooling tower
- chiller for water
- Equipment for humidification and dehumidification
HVAC System Classification
HVAC systems are divided into two types:
- Central systems
- Decentralized or local systems
The type of system depends on whether the primary equipment location is centralized, such as conditioning the entire building as a whole unit or decentralized, such as conditioning a specific zone as part of a building separately. As a result, the air and water distribution system should be designed based on system classification and primary equipment location. The above-mentioned criteria should also be used when deciding between two systems.
Central HVAC systems can serve multiple or single zones and can be located away from the building, eliminating the need for distribution devices. They are further divided into all-air HVAC systems, air-water systems, water-source heat pumps, and heating and cooling panel systems. Local HVAC systems are typically located inside or adjacent to living spaces and serve a single zone. Local heating systems, local air conditioning systems, local ventilation systems, and split systems are among them.
It is important to be knowledgeable about your HVAC system even before getting a dealer for installation. Being properly informed will assist you in making the right decision regarding the type of HVAC you need and what is appropriate for your space.
Contact a professional HVAC technician.