About Your Air Conditioning
The basic principles or air conditioning are misunderstood by most people, even by many in the field. Air conditioning is not simply just the process of cooling the air. It covers six different functions, defined below. All of these functions are required before the term “Air Conditioning” can be properly applied to a system.
Air conditioning was not used until about 1920, and then it was used mostly in public places such as theaters, trains, and some department stores. This is when the general public became aware of the benefits of air conditioning.
Air conditioning is usually applied to the cooling effect of a system. However, air conditioning, by definition, requires that six functions take place. These six functions are cooling, heating, air circulation, air cleaning, humidification, and dehumidification. The person who is to estimate an air conditioning job must have, at least, a working knowledge of the functions and how they affect the overall total operation of the system. Some of.these functions are required during all modes of operation.
When the system is operating in the cooling mode, the processes involved are air circulation, air cleaning, cooling, and dehumidifying the air. When the system is in the heating mode, the processes are heating, circulation, cleaning, and humidifying the air. It should be obvious that air circulation is a very important aspect of the total system operation.
There are basically two reasons for the use of an air conditioning system. The first is to improve some industrial or manufacturing process, and the second is to provide human comfort. The indoor conditions required are determined by the need and the desire of the occupants or the process. Thus, for human comfort applications, an understanding of the required body functions is fundamental to a proper understanding of air conditioning.
Human comfort depends on the rate at which the body loses heat. The human body is a heat machine that uses food as its fuel. The food that we cat contains the components carbon and hydrogen. The energy in these components is released by oxidation of the food. When we breathe in air, the oxygen that is taken from the air is necessary for the oxidation of the food. When we consider the products of combustion that occur in a gas flame, we know that -the products of combustion (oxidation) are carbon dioxide (CO2) and water vapor (H20). The medical profession terms this function as metabolism.
A natural function of the human body is to maintain itself at a constant temperature. The temperature that the mechanism attempts to maintain is 98.6°F. This temperature regulating mechanism is a very delicate part of the human body. The body always produces more heat than it needs; therefore, heat rejection is an ongoing process with the human body. The purpose of an air conditioning system is to help the body’s system to regulate this heat loss. This theory applies to both the heating and cooling functions of the system. During the summertime the purpose of the air conditioning system is to increase the cooling rate of the body. During the wintertime its job is to decrease the rate of cooling.