HVAC systems, which consist of the first letters of the English words Heating, Ventilating and Air Conditioning, mean ventilation, heating and air conditioning systems in Turkish. These three functions are generally combined in a single system in today's modern buildings.

In today's modern buildings, air conditioning control is of great importance due to both ventilation problems and air pollution increasing rapidly. The main purpose of HVAC systems positioned in buildings is to significantly increase the air quality in the environments where people live and to meet other comfort conditions at optimum temperatures.

What is HVAC Automation?

HVAC systems activate other ventilation systems at an appropriate level by receiving data such as appropriate pressure, temperature and humidity from the environments in which they are installed. It controls the temperature and pressure of the most suitable control systems that can be provided in HVAC systems with an automatic controller.

After this control, the system reaches the desired values by using limited energy. Because the most important feature of this system is that it provides the necessary conditions by reaching maximum efficiency in a short time with minimum energy.

HVAC Automation and Technical Specifications

The operation of an HVAC system in a heat-based manner is discussed. As a result of the measurements made with the necessary elements, the system provides air outlet or air inlet to the structure at the required values such as temperature and humidity. While ventilation and air control are carried out in the structure on the left side of the figure, water cooling and heating are carried out on the right side.

In the cooling tower, the cooling of the water is provided. If necessary, the air coming from the building is cooled along with the cooled water. If an increase in temperature is desired inside this building, the hot air coming out of the area where the steam boiler is located in the middle is easily transported into the building thanks to the pump and fan, thus providing temperature control in the buildings.

Although the conditions and area in which the system is used in HVAC systems vary, the main control systems on the system can be grouped under some headings. Control of the main system occurs by ensuring certain sub-controls within the system.

By collecting the data of a whole system, which is divided into small parts by performing some checks with sub-controls, from the sub-controls, connections within all sub-systems are provided and the control of the system is completed in this way.

More coordinated operation of HVAC systems is achieved thanks to the control elements located throughout the system and its subsystems. The main control elements in the system can be listed as follows;

  • Automatic Dampers
  • Valves
  • Sensors

Control devices that provide steam and water flow in HVAC systems, which are frequently used in buildings, are valves. Dampers are the elements that help control the air flow in the system. Various sensors such as temperature, humidity and pressure sensors are also used to receive data in the environments where the systems are installed.

Apart from the main control elements we have mentioned, there are also electrical auxiliary control elements in the system. Auxiliary control elements can also be listed as follows;

Transformers: They are used to transform the voltage taken from the network in a short time.

Electrical relays: These are the elements that provide control of fans, compressors, pumps and all other devices in the system and help switch high-energy devices.

Pneumatic electrical relays: They are important elements used to interrupt the pressurization circuit and switch the pressurization of the air.

Potentiometer: These are the elements that enable the controllable values of the environment such as pressure and temperature to be manually adjusted.

Pneumatic relays: They are used to control pressure control as well as to obtain numerical signals. These are various elements used in functions such as separating two very high or low pressures, averaging two or more pressures, adding or subtracting pressure by responding to two pressures of different amounts.

Electro-pneumatic relays: With these electrically managed relays, pneumatic elements in air valves can also be switched.

Air accessories and compressors: These are the elements that provide the pressure source required to dry and clean the air.

Switches: These are the elements that help dampers and valves operate sequentially.

Adjustment relays: These relays are various elements used to adjust the operating sensitivities of dampers and valves.

Switch relays: These are various elements that pneumatically provide opening and closing operations in ventilation relays.

Adjustment relays: These relays are frequently used elements to adjust the operating sensitivities of valves and dampers.

Energy Efficiency in HVAC Automation

Some ways can be followed to provide energy efficiency for the automation of HVAC systems. These are:

Time programming: It works during the operating hours of the building where the systems are installed and helps ensure that the system is shut down when the facility is closed.

Fancoil and radiator controls: All fancoil and radiator controls in the buildings are carried out through the building automation system, and as a result, the control devices that are not supposed to operate outside of operating hours are turned off.

Heat, enthalpy, humidity and air quality control: With the control based on the humidity, enthalpy, heat and air quality values that can be done for the air outside and inside the building, it prevents functions such as unnecessary cooling, heating, drying and humidification by using energy in the most efficient way.

Frequency converter according to pressure, level and pressure difference: Controlling fans and pumps frequently used in buildings with a frequency converter according to the measurement of values such as pressure, flow rate and pressure difference prevents excessive energy consumption.

What is AC?

Air Condition, or AC Systems in short, helps meet the air conditioning demands in HVAC automation systems and ensures that the cooling or heating needs of the area are easily met. These systems, also known as air conditioners, differ from home-type systems and work to meet the demands of much larger areas.

Air conditioning, which generally represents the process of removing moisture from the air for cooling or thermal comfort, can actually be preferred for the cooling process, although it also includes heating. In this way, it is also used in a wide sense for cooling, heating and improving the condition of the air.

Although air conditioners are the first AC systems that come to mind, large units are included in air conditioning devices. Air conditioners can also be preferred for more homes or smaller areas. However, in order to adequately meet the cooling demands of larger areas, specially developed devices must be used. The units that will be frequently used in these systems produce cold air through various channels and release this air to the environment.