*B. Fresh air handling unit (fresh AHU)*

In this type, air handling units are installed in the outdoor environment such as on the building roof. This type of air handling unit is called fresh air handling unit. Fresh air handling units are designed to withstand climatic variations. In addition,

*Central Air Conditioning: Systems and Applications DOI: http://dx.doi.org/10.5772/intechopen.89455*

It is may be of interest to note that the configuration of air handling unit can

application and AHU capacity (e.g., healthcare buildings or other), but also initial

The horizontal air handling units place the supply air fan, cooling coil, heating coil, and humidifier in the casing horizontally (see **Figure 2**). This design requires a large floor area as AHU components are large in size. Horizontal AHU type are usually of high capacity and are usually placed in plant room, whereas small

In vertical air handling units, the centrifugal fan is placed in a position above the cooling coil, heating coil, and humidifier as shown in **Figure 3**. Vertical air handling units are small in size and are low-capacity units, and thus they are installed in a

These air handling units are normally installed indoor in a plant room. This type

In this type, air handling units are installed in the outdoor environment such as on the building roof. This type of air handling unit is called fresh air handling unit. Fresh air handling units are designed to withstand climatic variations. In addition,

differ slightly in design and components according mainly to the type of

and running costs can affect the selection of various AHU components. In addition, air handinbased on various classificationsg units can be classified based on the structure and based on the location where it is placed [2]. The following sections will demonstrate all types of air handling units based on various

*2.1.1.1 Classification of air handling unit based on structure*

horizontal AHU type can be placed carefully on the roof [2].

*2.1.1.2 Classification of air handling unit based on location of installation*

*A schematic diagram of horizontal air handling unit. Redrawn with modification from [2].*

*A. Horizontal air handling unit (horizontal AHU)*

*B. Vertical air handling unit (vertical AHU)*

*A. Internal air handling unit (internal AHU)*

*B. Fresh air handling unit (fresh AHU)*

**Figure 2.**

**4**

of air handling unit is called simply air handling unit [1].

small floor area of plant room [2].

classifications.

*Low-temperature Technologies*

#### **Figure 3.** *A schematic diagram of vertical air handling unit. Redrawn with modification from [2].*

safety measures must be taken before installing fresh air handling units on roofs due to their large weights [2].
