How does an air conditioner work?


An air conditioner cools a room, a whole house, or an entire business premise. Air conditioners use chemicals that easily convert from a gas to a liquid and back again. This chemical is used to transfer heat from the air inside of a home to the outside air. The machine has three main parts. They are a compressor, a condenser and an evaporator. The compressor and condenser are usually located on the outside air portion of the air conditioner. The evaporator is located on the inside the house, sometimes as part of a furnace. That's the part that heats your house.


The working fluid arrives at the compressor as a cool, low-pressure gas. The compressor squeezes the fluid. This packs the molecule of the fluid closer together. The closer the molecules are together, the high its energy and its temperature. The working fluid leaves the compressor as a hot, high pressure gas and flows into the condenser. If you looked at the air conditioner part outside a house, look for the part that has metal fins all around. The fins act just like a radiator in a car and helps the heat go away, or dissipate, more quickly. When the working fluid leaves the condenser, its temperature is much cooler and it has changed from a gas to a liquid under high pressure. The liquid goes into the evaporator through a very tiny, narrow hole. On the other side, the liquid's pressure drops. When it does it begins to evaporate into a gas. As the liquid changes to gas and evaporates, it extracts heat from the air around it. The heat in the air is needed to separate the molecules of the fluid from a liquid to a gas. The evaporator also has metal fins to help in exchange the thermal energy with the surrounding air.


By the time the working fluid leaves the evaporator, it is a cool, low pressure gas. It then returns to the compressor to begin its trip all over again. Connected to the evaporator is a fan that circulates the air inside the house to blow across the evaporator fins. Hot air is lighter than cold air, so the hot air in the room rises to the top of a room. There is a vent there where air is sucked into the air conditioner and goes down ducts. The hot air is used to cool the gas in the evaporator. As the heat is removed from the air, the air is cooled. It is then blown into the house through other ducts usually at the floor level. This continues over and over and over until the room reaches the temperature you want the room cooled to. The thermostat senses that the temperature has reached the right setting and turns off the air conditioner. As the room warms up, the thermostat turns the air conditioner back on until the room reaches the temperature.


My air conditioning is not working - What can I do?


One of the most common causes of failure is that some one has switched off the power supply. So check that fuses circuit breakers and isolators are all OK and working.


Another common cause is blocked air filters, so check they are clean and are regularly kept clean. It helps to refer to the manufacturers operating instructions as well.


Also check the remote for mode (cooling, dry or fan), temperature, fan speed etc. If all else fails and you are still having a problem, contact our service department.


My system has a warranty - Why do I need a maintenance contract?


Air conditioning and building services systems require regular maintenance to ensure safety and optimum operational efficiency. Warranties are only applicable if the system or equipment is regularly maintained by an approved organisation.


To simply explain, relate this to a car which like air conditioning has many rotating and wearing parts, your warranty will not be honoured if you don't have regular servicing (maintenance)


I have been told that air conditioning spreads viruses and bacteria - Does it?


No more than you do or any ventilation system does for airborne viruses and bacteria. Many people are susceptible to dryness sometimes caused when an air conditioning system is badly designed or maintained and the relative humidity is reduced too much. It's a fact that basically coughs and sneezes spread diseases.


Explain the difference between air conditioning, comfort cooling and close control?


Air conditioning covers many things but is mainly, heating, cooling, ventilation, fresh air, filtration and control of humidity. Comfort cooling mainly relates to provision of just cooling to improve comfort.


Close control air conditioning is really as the name implies, both temperature, humidity and air cleanliness are closely controlled and often to fine tolerances if necessary.

  • Cleaning air conditioners: it is recommended to clean air conditioners for better life of the machine and your environment. One cause of indoor air contamination is due to bacterial and fungal contamination of air filters, heat transfer coils and ductwork within airconditioning systems that are poorly designed and maintained.
  • Coefficient of performance: The efficiency of a refrigeration system is measured by its coefficient of performance (COP), and is normally given as the ratio of the refrigeration effect to the compressor power: ?COP = (Cooling output) / (Electrical input) ??For most packaged commercial cooling units the COP varies between 2.5 and 4.0. However, some modern commercial cooling units have COPs of about 5.0. As the external temperature increases the COP is progressively reduced to about 2.0 at 40°C.
  • Saving Energy when using air conditioners: There are some simple things you can do to save energy when using an air conditioner:
    • Install the air conditioner (or outdoor unit of a split system) on the shady side of the building (or shade the air conditioner itself); make sure the air flow around it isn't obstructed.
    • The temperature of a cooled room in summer should be about 23-26°C (remember the humidity indoors will be low, so it will feel cooler). The temperature should be checked after the air conditioner has been operating for 30 minutes.
    • When a hot day is expected, turn on the air conditioner early rather than wait till the building becomes hot (it operates more efficiently when the outside air temperature is cooler).
    • Keep windows and doors closed when using a refrigerative air conditioners (evaporative air conditioners require some air flow). Close curtains on hot summer and days and cold winter nights. Outdoor shading of windows in summer is most effective.
    • If the machine has adjustable louvres, adjust them towards the ceiling when cooling, and towards the floor when heating (as cool air falls, hot air rises).
    • Follow the manual instructions for filter cleaning.
  • Inverter: Through new, advanced technology, Inverter air conditioners are more economical to operate and quieter to run than conventional units. They can handle greater extremes in temperature, are smoother and more stable in operation, and reach the desired temperature more quickly than conventional air conditioners.
  • Temperature for efficient use of air conditioner: The Queensland government (Australia) promotes 24 degrees Celsius as being the recommended temperature for the efficient use of an air conditioner when cooling. This is supposedly a temperature that keeps you comfortable and does not use undue power to the unit.


What does an inverter do?


An electrical inverter is used to vary the frequency of the power supply from a normal 50Hz enabling fine step speed control of motors (compressors) this in turn varies the quantity of refrigerant delivered and hence variable cooling or heating capacity.


What is COP?


Coefficient of Performance, which is the ratio between the power input and power output. For example a modern heat pump will provide 3kw of heat for 1kw of electrical power input. Therefore the COP is expressed as 3 - 1.


What is EER?


Energy efficiency ratio is used to express the relative efficiency of a heating or cooling device by dividing the heat output by the power input. The higher the ratio compared to others, the better the system is.


What is Energy Labelling?


Energy labeling is a new way of allowing consumers to easily compare and rate the efficiency of air conditioners and systems as per the stringent government and environment norms, the higher the star rating, the higher the efficiency. For more information kindly visit www.bee-india.nic.in/