Conditioning system

The design of air conditioning systems is a highly specialized branch of engineering. A number of excellent information sources regarding air conditioning are available (1). 

Eundamental to the design of any air conditioning system is the determination of the operating conditions of temperature and humidity. Worker comfort must also be considered. 

The following information is customarily requited for thorough design of new air conditioning systems or renovation of existing systems. 

Dehumidification. Dehumidification may be accompHshed in several ways (see Drying). Moderate changes in humidity can be made by exposing the air stream to a surface whose temperature is below the dew point of the air. The air is cooled and releases a portion of its moisture. Closed cycle air conditioning systems normally effect dehumidification also. The cooled air may require reheating to attain the desired dry-bulb temperature if there is insufficient sensible load in the space. 

Axial fans are classified as propeller, tube-axial, and vane-axial (Fig. 9). The choice of fan requited is determined by the resistance (static pressure) the fan must work against as well as the volume flow requited. PtopeUet fans usually discharge iato a plenum or directly iato the atmosphere. Tube-axial fans are usually mounted ia ducts as ia an air conditioning system. Vane-axial fans are also mounted ia ducts but feature a stationary guide vane on the discharge side that straightens the air flow to improve efficiency. Tube-axial fans can work at static pressures up to 623 Pa (2.5 ia. H2O) vane-axial fans can work up to 2000 Pa (8 ia. H2O). 

Although the temperature can be controlled with a weU-designed air-conditioning system, the small fluctuations which most cycling systems cause may be very harmful. The temperature—time record should be a continuous, flat graph. 

A lemon scent pumped through the air-conditioning system of a Japanese office building increased workers productivity. 

Acid cleaners based on sulfamic acid are used in a large variety of appHcations, eg, air-conditioning systems marine equipment, including salt water stills wells (water, oil, and gas) household equipment, eg, copper-ware, steam irons, humidifiers, dishwashers, toilet bowls, and brick and other masonry tartar removal of false teeth (50) dairy equipment, eg, pasteurizers, evaporators, preheaters, and storage tanks industrial boilers, condensers, heat exchangers, and preheaters food-processing equipment brewery equipment (see Beer) sugar evaporators and paper-mill equipment (see also Evaporation Metal surface treati nts Pulp). 

Small refrigerators were developed by several companies and some were even installed in hotel rooms in Chicago. Borg-Wamer and other companies produced many compact systems for laboratory uses (23). Air-Industry in Erance built an air conditioning system for a passenger railway coach that was stiH in daily use after 10 years of operations without a single thermoelectric failure (24). 

Fig. 20. Steam-tube rotary dryer using a dry product recycle and feed conditioning system.

In industrial air-conditioning systems, harmful environmental gases, vapors, dusts, and fumes are often encountered. These contaminants can be controlled by exhaust systems at the source, by dilution ventilation, or by a combination of the two methods. When exhaust... 

Basically, an air-conditioning system consists of a fan unit which forces a mixture of fresh outdoor air and room air through a series of devices which 2LCt upon the air to clean it, to increase or decrease its temperature, and to increase or decrease its water-vapor content or humidity. 

Figure 1.4 Schematic of all components of a complete air-conditioning system. [Fig. 37.8, The Nalco Water Handbook, 1st ed. (1979), reprinted with permission from McGraw-Hill, Inc. ]...

Pinhole perforations were discovered in the walls of chiller condenser tubes of an air-conditioning system. Close laboratory examination of the internal surfaces of affected tubes revealed distinct patches of small pits (Fig. 12.18) and pit sites aligned along longitudinal mandrel marks and fine scratches (Fig. 12.19). In some locations, transversely oriented pit sites that were aligned with the locations of the fins on the external surface branched off the primary longitudinal pit alignment (Fig. 12.20). 

The concentration of indoor pollutants is a function of removal processes such as dilution, filtration, and destruction. Dilution is a function of the air exchange rate and the ambient air quality. Gases and particulate matter may also be removed from indoor air by deposition on surfaces. Filtration systems are part of many ventilahon systems. As air is circulated by the air-conditioning system it passes through a filter which can remove some of the particulate matter. The removal efficiency depends on particle size. In addition, some reactive gases like NOj and SOj are readily adsorbed on interior surfaces of a building or home. 

If you have questions about your auto air conditioning system the site www.aircondition.com has a question-and-answer bulletin board for interactive responses. 

---