Category: Refrigeration And Air Conditioning

When moist air is cooled below its dew point by bringing it in contact with a cold surface, some of the water vapour in the air condenses and leaves the air stream as liquid, as a result both the temperature and humidity ratio of air decreases as shown. This is the process air undergoes in…

During this process, the moisture content of air remains constant but its temperature decreases as it passes over a cooling coil. To keep the moisture content constant, the surface of the cooling coil should be dry and its surface temperature should be greater than the dew point temperature (DPT) of air. If the cooling coil…

8.8.1  Psychrometric Chart A view of psychrometric chart is shown in Figure 8.6. The different psychrometric process are shown in Figure 8.7. Figure 8.6 Psychrometric Chart Figure 8.7 Psychrometric Processes

Psychrometry is the study of air–water vapour mixtures. It is also sometimes referred to as hygrometry. Many mechanical engineering devices exploit psychrometric processes, such as air conditioning systems and cooling towers. Two important principles upon which psychrometric relationships are based are the perfect gas equation and Dalton’s law regarding the mixture. The perfect gas equation, PV = RT,…

This is not widely used model. For those who want fresh food selection at eye level, this model is most suitable for their household. The configuration is similar to that of the top mounted freezer refrigerators and the cooling is more even. It does not use much energy to keep the section cool. The main…

This refrigerator is more expensive as compared to the top-mount refrigerator. This is more advanced with features such as through the door cool water dispenser. With the freezer and the fridge being adjacent to each other, it allows easy access to food items that are stored. However, this refrigerator has its own disadvantage. Apart from…

This is the most common type of refrigerator. The refrigerator has wider shelves in both the freezer and fridge. In this refrigerator, the freezer is placed at the top level. Generally, the height of the freezer varies in between 60 and 69 in., which is why they tend to offer more storage capacity as compared…

A refrigerator maintains the temperature slightly higher than the freezing point of the water. There is a freezer which maintains the temperature below the freezing point of water. As far as the classification of refrigerators is concerned, it can be widely classified into four classes. They are top-mount freezer refrigerator, side-by-side refrigerators, freezer on bottom,…

Research on use of refrigerant is continuously going on due to adverse effect on depletion of ozone layer. The production of many refrigerants will soon end, including R-22 and R-123 in accordance to the requirements of the Montreal Protocol. Suppliers currently offer a range of refrigerants based on chiller type, capacity, and regulatory requirements. The refrigerants…

The absorption cycle is a process by which refrigeration effect is produced through the use of two fluids and some quantity of heat input, rather than electrical input as in the more familiar vapour compression cycle. Both vapour compression and absorption refrigeration cycles accomplish the removal of heat through the evaporation of a refrigerant at…