1.0 Introduction
1.1 Air Conditioner
An air conditioner system is an assembly of various components which operate in a controlled manner to produce a specified condition of the air within a space or building.
To produce complete air conditioning, a system must heat, humidify, cool, dehumidify ventilate, filter and circulate air within the conditioned space all for the comfort of the user.
Air conditioner has a wide range of capacities for rooms of various sizes. It has been common to rate units in tons but a better method is by BTU (British Thermal Unit). A small capacity air conditioner may be 5500 BTU and a larger one 15,000 BTU. It can also be rated by horse power, which describes the power needed to drive electric component and not cooling capacity. The capacity required is determined by size of space to be cooled, the building installation, direction of window to sun or shade, heat source in the room (from a gadget0 and the normal occupancy.
The electric voltage required is normally between 115 — 230 volts.
1.2 Historical Background
The roots of air conditioning as we know today, are in refrigeration. T he elements of an air conditioning system were well known before the first complete system was built in 1902. Before now, fans and refrigeration had been invented, ice had been used for cooling for centuries and there had been duct work for central heating.
The first systematized approach to control indoor atmosphere was made by Willis Carrier, a 25 year old engineer for a Buffals N.Y. heating firm. The problem was that hot humid summer air was causing faulty reproduction of four colour illustrations for a litographic form in Brooklyn. N.Y. Carriers machine combined cooling and humidity control for summer and heating and humidifying for winter. He used fans to blow the hot humid air over coils of cold water piped from ammonia frigeration machine. He worked out the proper amount of cold coil surface needed and required temperature and air conditioning.
In 1906 Stawart Grammer applied it in 1911 Carriers' rational psychometric formula, set forth the data necessary to design relationship between moisture content and temperature, and enabled engineers to calculate the requirement for air conditioner. The development of lightweight formed coiling coils made possible a more effective heat transfer surface from the warm air to the refrigerating coils. Gas refrigerants were considered dangerous for small installation until the first toxic refrigerant, feron was invented. It made possible installation of home air conditioning units and room air conditioner.
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