Commonly Used HVAC Terms and Explanations Part 1

1. Central air-conditioning: Central air-conditioning is an air-conditioning system that controls different rooms by means of a main unit connecting multiple ends through air ducts or cold and hot water pipes, so as to achieve the purpose of indoor air conditioning. That is to say, the heating and cooling of all rooms are supplied by it, and there are only blowers in each room, and all the outdoor units that originally refrigerated are put into one box.

2. Central air-conditioning system: There are host and final system. According to the media used to bear the indoor heat and humidity load, it can be divided into all-air systems, all-water systems, air-water systems, and refrigerant systems. According to the degree of concentration of air handling equipment, it can be divided into centralized and semi-centralized. According to the source of the treated air, it can be divided into closed type, direct flow type and mixed type. The main components are air-conditioning host (cold and heat source), wind cabinet, fan coil unit and so on.

3. Refrigerant: Refrigerant is the working medium that completes the refrigeration cycle in the refrigeration system. The refrigerant absorbs the heat of the cooled object in the evaporator and evaporates, and transfers the heat to the surrounding air or water in the condenser to be condensed into a liquid body. The refrigerator achieves the purpose of refrigeration by means of the state change of the refrigerant.

4. Cooling capacity: When the air conditioner is in cooling operation, the heat absorbed by the low-pressure side refrigerant in the evaporator per unit time, the common unit is W or KW.

5. Heat pump heating capacity: when the air conditioner is in heat pump heating operation (the heat pump auxiliary electric heater should be running at the same time), the heat sent into the confined space, room or area per unit time. The coefficient of performance is the ratio of the amount of refrigeration (heat) generated in the refrigeration (heat) cycle to the power consumed by refrigeration (heat) is the coefficient of performance. Refrigeration is called the energy efficiency ratio, expressed in EER. Heating is called the coefficient of performance, expressed in COP.

6. Secondary refrigerant: Secondary refrigerant refers to the intermediate medium used to transfer cold energy in the indirect refrigeration system. After the brine is cooled by the refrigerant in the evaporator, it is sent to the cooling equipment for cooling, absorbs the heat of the cooled object or the environment, and then returns to the evaporator to be re-cooled by the refrigerant. Such a continuous cycle, in order to achieve the purpose of continuous refrigeration.

7. Fan coil unit: heat exchange equipment commonly used in centralized central air conditioning systems, consisting of finned tubes and fans. When the brine flows through the fan coil (inside the tube), it exchanges heat with the air at the tube to cool down the air. Fan coil units are air cooling equipment.

8. Water-cooled chiller: The water-cooled chiller is part of the refrigeration unit in the central air-conditioning system. Its refrigerant is water, which is called a chiller. The cooling of the condenser is realized by using the heat exchange and cooling of normal temperature water, so it is called a water-cooled unit. The opposite of the water-cooled machine is called an air-cooled unit, and the condenser of the air-cooled unit achieves the purpose of cooling by forced ventilation and heat exchange with the room air.

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The characteristics, design methods and comparison of commonly used air-conditioning systems Part Two

Central Air-conditioning Construction Site Experience-Part 2

The pre-installation of air conditioning ducts, step by step

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The characteristics, design methods and comparison of commonly used air-conditioning systems Part Three

Central Air-conditioning Construction Site Experience-Part 3

Reasons why factory-made air ducts are more advantageous than on-site production

The characteristics, design methods and comparison of commonly used air-conditioning systems Part Four