HVAC
Commercial Air-conditioning or
HVAC (Heating, Ventilation and Air
Conditioning)
J.Ilangumaran
Commercial air-conditioning or HVAC (Heating,
Ventilation and Air Conditioning)
It refers to the mechanical systems which heat, cool, filter or dehumidify air in a room or building.
HVAC systems control the ambient environment
(temperature, humidity, air flow, and air filtering) in homes and commercial buildings and are crucial in maintaining environmental conditions in critical applications such as data centers, medical rooms, computer server rooms, and other clean room applications.
TYPES OF COOLING SYSTEMS
The most common air-cooling systems are either direct expansion
(DX) type or the chilled water type.
DIRECT EXPANSION (DX) SYSTEMS
In DX systems, the air is cooled with direct exchange of heat with refrigerant passing through the tubes of the finned cooling coil. All these systems are comprised of a hermetically sealed or open compressor(s), evaporator
(cooling coil fabricated out of copper tubes and aluminum fins), a supply air blower, filter, a condenser and heat rejection propeller fan.
Unitary System
In a unitary system, the complete cooling system is in one casing. Since all equipment is prepackaged, the installation cost is usually lower, and the performance quality is often higher than field-erected systems. Window airconditioners, package units are typical examples of unitary DX systems
Split System
The second DX concept, where the evaporator is separate from the condenser/compressor, is called a split system. These are commonly found in residential and small commercial installations with capacity ranges varying 1 to 50 TR and suitable for an area of
100 – 10000 square feet. The new ductless systems which can be conveniently mounted on the ceiling or wall are in this family
HYDRONIC or CHILLED WATER SYSTEMS
In a chilled water system the air is cooled with chilled water passing through the tubes
HVAC (Heating, Ventilation and Air
Conditioning)
J.Ilangumaran
Commercial air-conditioning or HVAC (Heating,
Ventilation and Air Conditioning)
It refers to the mechanical systems which heat, cool, filter or dehumidify air in a room or building.
HVAC systems control the ambient environment
(temperature, humidity, air flow, and air filtering) in homes and commercial buildings and are crucial in maintaining environmental conditions in critical applications such as data centers, medical rooms, computer server rooms, and other clean room applications.
TYPES OF COOLING SYSTEMS
The most common air-cooling systems are either direct expansion
(DX) type or the chilled water type.
DIRECT EXPANSION (DX) SYSTEMS
In DX systems, the air is cooled with direct exchange of heat with refrigerant passing through the tubes of the finned cooling coil. All these systems are comprised of a hermetically sealed or open compressor(s), evaporator
(cooling coil fabricated out of copper tubes and aluminum fins), a supply air blower, filter, a condenser and heat rejection propeller fan.
Unitary System
In a unitary system, the complete cooling system is in one casing. Since all equipment is prepackaged, the installation cost is usually lower, and the performance quality is often higher than field-erected systems. Window airconditioners, package units are typical examples of unitary DX systems
Split System
The second DX concept, where the evaporator is separate from the condenser/compressor, is called a split system. These are commonly found in residential and small commercial installations with capacity ranges varying 1 to 50 TR and suitable for an area of
100 – 10000 square feet. The new ductless systems which can be conveniently mounted on the ceiling or wall are in this family
HYDRONIC or CHILLED WATER SYSTEMS
In a chilled water system the air is cooled with chilled water passing through the tubes