Air conditioning in buildings

Ironically, the two applications that Midgley developed CFCs for— refrigeration and air-conditioning in buildings—accounted for less than one-fifth of the CFCs used by the United States at their peak in 1985. More than half of all CFCs were in industrial solvents—uses that Midgley may never have imagined. 

Australian Standard 1668.2-1992 (1992) The use of mechanical ventilation and air conditioning in buildings. Part 2 Mechanical ventilation for acceptable indoor air quality. Standards Australia. 

These heaters are avaifable with rotors up to 6 m (20 ft) in diameter. Gas temperatures up to 1255 K (1800°F) can be accommodated. Gas face velocity is usually around 2.5 m/s (500 ft/min). The rotor height depends on service, efficiency, and operating conditions but usually is between 0.2 and 0.91 m (8 and 36 in). Rotors are driven by small motors with rotor speed up to 20 r/min. Heater effectiveness can be as high as 85 to 90 percent neat recovery. Lungstrom-type heaters are used in power-plant boilers and also in the process industries for heat recoveiy and for air-conditioning and building heating. 

Volatile organic compounds (VOCs) and carbon dioxide (C02) are two major indicators of indoor air pollution in air-conditioned office buildings. Indoor air quality assessments would include VOCs and C02 measurements and attempt to identify their sources so that strategies for effective control may be implemented. Options for control may be source control and ventilation. Source control is the more effective while ventilation is potentially expensive, given the unpredictable (and usually rising) cost of energy. 

Ventilation characteristics of an air-conditioned office building in Singapore. Building and Environment, 37, 241-55. 

Sekhar, S.C., Cheong, K.W., Tham, K.W. and Phua, B.L. (2003a) Effectiveness of purging in an air-conditioned office building in Singapore. The International Journal of Ventilation, 2 (3), 237-50. 

The effects of ventilation operations in determining conttibutions of VOCs sources in air-conditioned ttopical buildings. Building and Environment, 38 (1), 23-32. 

Refrigeration is best known for its use in the air conditioning of buildings and in the treatment, transportation, and preservation of foods and beverages. It also finds large-scale industrial use, for example, in the manufacture of ice and the dehydration of gases. Applications in the petroleum industry include lubricating-oil purification, low-temperature reactions, and separation of volatile hydro-1 carbons. A closely related process is gas liquefaction, which has important commercial applications. 

Zuraimi MS, Tham KW, Sekhar SC (2002) Identification and quantification of VOCs sources in air-conditioned office buildings in Singapore. Proceedings of the 9th international conference on indoor air quality and climate. Monterey, CA, USA, p 183 Adgate JL, Bollenbeck M, Eberly LE, Stroebel C, PeUizzari ED, Sexton K (2002) Residential VOC concentrations in probability based sample of household with children. Proceedings of the 9th international conference on indoor air quality and climate. Monterey, CA, USA, p 203... 

Commercial office buildings in most regions of the country typically do not require heating for most of the year, and their hot-water needs are minor. But, many commercial office buildings require air conditioning in the summer and other times of the year due to internal heat generated by the occupants, equipment and lighting. 

In many countries the building codes include certain general regulations to guarantee proper and sanitary conditions in buildings. Generally it is required that the indoor environment should not be injurious to health and that indoor air quality should be at least the same as outdoor air quality, e. g., as is stated in a German directive on non-industrial workplaces (Bundesanstalt fur Arbeitsschutz, 1988). 

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