Indoors

Scandium iodide added to mercury vapor lamps produces a highly efficient light source resembling sunlight, which is important for indoor or night-time color TV. 

Fig. 4. Circular tanks are a raceway option. They can be placed outdoors or used in conjunction with indoor water systems. Circular tanks are commonly...

Applications. Both industrial emissions reduction and indoor air-poUution abatement uses will grow. For example, the development of adsorbents with higher capacity for removal of radon from humid air could allow the development of a one-bed, delay-for-decay system in which radon adsorbs, decays to lead, and is precipitated onto the adsorbent. 

Eigure 3 shows the winter and summer comfort zones plotted on the coordinates of the ASHRAE psychrometric chart. These zones should provide acceptable conditions for room occupants wearing typical indoor clothing who are at or near sedentary activity. Eigure 3 appHes generally to altitudes from sea level to 2150 m and to the common case for indoor thermal environments where the temperature of the surfaces (/) approximately equals air temperature (/ and the air velocity is less than 0.25 m/s. A wide range of environmental appHcations is covered by ASHRAE Comfort Standard 55 (5). Offices, homes, schools, shops, theaters, and many other appHcations are covered by this specification. 

Humidification. For wiater operation, or for special process requirements, humidification maybe required (see Simultaneous HEAT and mass transfer). Humidification can be effected by an air washer which employs direct water sprays (see Evaporation). Regulation is maintained by cycling the water sprays or by temperature control of the air or water. Where a large humidification capacity is required, an ejector which direcdy mixes air and water in a no22le may be employed. Steam may be used to power the no22le. Live low pressure steam can also be released directly into the air stream. Capillary-type humidifiers employ wetted porous media to provide extended air and water contact. Pan-type humidifiers are employed where the required capacity is small. A water filled pan is located on one side of the air duct. The water is heated electrically or by steam. The use of steam, however, necessitates additional boiler feed water treatment and may add odors to the air stream. Direct use of steam for humidification also requires careful attention to indoor air quahty. 

Whenever unvented combustion occurs iadoors or when venting systems attached to combustion units malfunction, a variety of combustion products win be released to the iadoor environment. Iadoor combustioa units include nonelectric stoves and ovens, furnaces, hot water heaters, space heaters, and wood-burning fireplaces or stoves. Products of combustion include CO, NO, NO2, fine particles, aldehydes, polynuclear aromatics, and other organic compounds. Especially dangerous sources are unvented gas and kerosene [8008-20-6] space heaters which discharge pollutants directly into the living space. The best way to prevent the accumulation of combustion products indoors is to make sure all units are properly vented and properly maintained. 

Air contaminants are emitted to the indoor air from a wide variety of activities and consumer products, some of which are summarized in Table 11. Most indoor activities produce some types of pollutants. When using volatile products or engaging in the activities Hsted, care should be exercised to minimize exposure through proper use of the product and by providing adequate ventilation. 

Table 11. Emission Mechanisms of Indoor Air Pollutants Arising from Activities and Consumer Products ...

California Department of Consumer Affairs, Clean Your Room, Compendium on Indoor Air Pollution, Sacramento, Calif., 1982, p. III.EI—III.E.II. 

Indoor Air Pollutants, National Academy Press, Washiagton, D.C., 1981, p. 101. 

J. M. Samet andj. D. Spengler, eds. Indoor Air Pollution, Johns Hopkins University Press, Baltimore, Md., 1991. 

Cables are available in a variety of constmctions and materials, in order to meet the requirements of industry specifications and the physical environment. For indoor usage, such as for Local Area Networks (LAN), the codes require that the cables should pass very strict fire and smoke release specifications. In these cases, highly dame retardant and low smoke materials are used, based on halogenated polymers such as duorinated ethylene—propylene polymers (like PTFE or FEP) or poly(vinyl chloride) (PVC). Eor outdoor usage, where fire retardancy is not an issue, polyethylene can be used at a lower cost. 

Interferometric systems, usually heflum-neon lasers, offer precise distance measurement over a scale of distances <100 m and in an indoor environment. Such devices are suitable for dimensional control of machine tools (see Machining MATERIALS, ELECTROCHEMICAL). 

A method which competes with interferometric distance measurement is laser Doppler displacement. In this approach the Doppler shift of the beam reflected from a target is measured and integrated to obtain displacement. This method also is best suited to use indoors at distances no more than a few hundred meters. Table 2 compares some of the characteristics of these laser-based methods of distance measurement. 

Whereas the eadiest fluorescent-dye pigments would last only 20 days outdoors in a screen-ink film, fade resistance has been improved to such an extent that some modem daylight-fluorescent coated panels stiU have useful color after nine months or mote in Florida sunlight in a 45° exposure tack facing south. The fluorescent layer is usually coated with an acrylic film containing a uv absorber. Indoor-accelerated exposure equipment is, of course, invaluable in the development of such systems. Better dyes and resins very likely will make possible fat mote stable coatings in the future. 

The identification of pollution prevention options has become a maintenance requirement. In addition to these requirements, the National Institute of Occupational Safety and Health (NIOSH) performed its first investigation of indoor air quahty. The U.S. Department of Energy (DOE) has also begun to research air quahty. 

Avoiding sick building syndrome requires special consideration of building constmction and maintenance material used. Asbestos, organic solvents, paint sprays, dirty filters, moist environment caused by poorly maintained humidifiers, and dirty HVAC machinery have contributed to the deterioration of indoor air quahty. Nonstop quahty maintenance is required at all times. 

Industry has standardized procedures for the quantitative sensory assessment of the perceived olfactory intensity of indoor malodors and their relationship to the deodorant efficacy of air freshener products. Synthetic malodors are used for these evaluation purposes. These malodors should be hedonicaHy associated to the "real" malodor, and must be readily available and of consistent odor quaUty. These malodors should be tested in various concentrations and be representative of intensities experienced under normal domestic conditions. 

Indoor Pests cockroaches, fleas, flies, Hce, carpet beetles, clothes moths, silverfish, centipedes, millipedes, termites mice, rats mil dew... 

Flammable Hquids used in indoor workplaces and laboratories should be contained in approved safety cans having self-closing spouts and flash... 

Report prepared for CMA, Washington, D.C., Indoor DEHP Mir Concentrations Predicted after DEHP Volatilitiesfrom Vinyl Products, Environ. Corp., 1988. 

A grass-like artificial surface was installed for the first time in 1964, at Moses Brown School (Providence, Rhode Island) (1). In 1966, artificial turf was installed in the Houston Astrodome in Texas. These surfaces consisted of green pigmented, nylon-6,6 pile ribbon, with a cross-section resembling that of natural grass. Since that period, other fabrics of various pile ribbon and constmctions have continued to become available commercially for indoor and outdoor facihties. 

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