Air Conditioner BasicsIn simplistic terms an Air Conditioner is an appliance that extracts heat from your room, takes it through the refrigeration cycle, and pumps the cool air back into the room. ACs have following primary components:
AC Compressor A compressor unit of an AC increases the pressure of the gas by reducing its volume. The gas compression effectively increases its temperature. With the technology advancements there are many compressor types today each having its own pros and cons. The primary compressor types include Reciprocating, Rotary, and Scroll. Reciprocating compressors offer a great range of compression pressures - from 5hp to 1000hp. They are generally used as small to medium duty systems. Many car ACs use reciprocating compressors. The downside of reciprocating compressors is that they produce high levels of noise and the units are also bulkier. The higher noise is attributed to the piston that the compressor uses for compressing the air, and the size to the cylinder requirement. Rotary compressors are compact and less noisy. They come in two types - a) Screw b) Vane compressors. Both use a rotating devices for air compression. In case of Rotary Screw compressor two helical screws are used to force the air into a compact unit whereas in Vane compressor single rotating device having multiple blades is used to accomplish the same objective. Rotary compressors can range from 3hp to 1200hp. The smaller versions are used in portable air conditioners. Scroll compressors are by far the quietest compressors. They use two vanes for compressing the air. Different manufacturers may use different shapes for the vanes. Generally, one of the vanes is fixed while the other revolves around it to compress the gas. Scroll compressors are considered most reliable. The rotary and screw compressors give higher compression ratio as compared to reciprocating ones.
The condenser unit of the Air Conditioner is responsible for condensing the refrigerant gas or vapor into liquid. The condensation process reduces the gas temperature to its dew-point thereby transforming it into liquid form. It's an important component of the AC. There are various types of condensers, the one used in refrigerator is called Air Coil. The capacity of the compresser determines how much and how fast the air will be pushed through the condenser which in turn determines how efficiently the AC will work. The shape of the condenser coil contributes to the size of the AC. A spiral coil, for example, takes lesser room. The condensing could occur in single or multi-phases. Evaporator Coil This is also known as cooling coil. The thermal expansion valve of AC releases the high pressure regrigerant liquid into the cooling coil. The liquid evaporates (converts into gas) dropping the temperature of the refrigerant and thereby cooling the evaporator coil. Once the evaporator coil is cool any air that comes in its contact also cools down which is the directed towards the room or area being air conditioned.
How does an AC work? The compressor compresses the refrigerant gas (like Freon) which is then cooled in the condenser unit before being sent through the evaporator coil to cool the air that circulates around it. A blower propels this cooled air around the coil out into the room. ACs essentially work just like refrigerators. A typical refrigeration cycle goes as below:
The effectiveness, safety, durability, and the prices of air conditioners vary depending upon what technology they are using for different components. Knowing the basics of ACs can help you better compare your options. Modern ACs can include many add-on features like Air Filter that removes dust and other impurities from the air, Dehumidifier that removes the excess humidity from the air. The complete AC systems called as HVAC offer Heating, Ventilation, and Air-Conditioning all in one. Resources:
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