**3. Basic components of an HVAC system**

The basic components or equipment of an HVAC system that delivers conditioned air to satisfy thermal comfort of space and occupants and the achieve the indoor air quality are listed below [3]:


systems in a given building will depend on the climate, the age of the building, the individual preferences of the owner of the building and a designer of a project, the project budget, the

HVAC systems can be classified according to necessary processes and distribution process [2]. The required processes include the heating process, the cooling process, and ventilation process. Other processes can be added such as humidification and dehumidification process. These process can be achieved by using suitable HVAC equipment such as heating systems, air-conditioning systems, ventilation fans, and dehumidifiers. The HVAC systems need the distribution system to deliver the required amount of air with the desired environmental condition. The distribution system mainly varies according to the refrigerant type and the delivering method such as air handling equipment, fan coils, air ducts, and water pipes.

System selection depends on three main factors including the building configuration, the climate conditions, and the owner desire [2]. The design engineer is responsible for considering various systems and recommending more than one system to meet the goal and satisfy the owner of a building. Some criteria can be considered such as climate change (e.g., temperature, humidity, and space pressure), building capacity, spatial requirements, cost such as capital cost, operating cost, and maintenance cost, life cycle analysis, and reliability and flexibility. However, the selection of a system has some constraints that must be determined. These constraints include the available capacity according to standards, building configuration, available space, construction budget, the available utility source, heating and cooling building loads.

The basic components or equipment of an HVAC system that delivers conditioned air to satisfy thermal comfort of space and occupants and the achieve the indoor air quality are listed

architectural design of the buildings [1].

50 HVAC System

**2. HVAC system selection**

below [3]:

**b.** Air filter

**f.** Ducts

**c.** Supply fan

**e.** Outdoor air intake

**g.** Terminal devices **h.** Return air system

**3. Basic components of an HVAC system**

**a.** Mixed-air plenum and outdoor air control

**d.** Exhaust or relief fans and an air outlet

