9.20 2001 ASHRAE Fundamentals Handbook (SI) Rohles, F.H., J.A. Woods, and P.R. Morey. 1989. Indoor environmental acceptability: Development of a rating scale. ASHRAE Transactions 95(1):23-27. Samet, J.M., M.C. Marbury, and J.D. Spengler. 1987. Health effects and sources of indoor air pollution. Am. Rev. Respir. Disease 136:1486-1508. Samet, J.M. 1989. Radon and lung cancer. J. Natl. Cancer Institute 81:145. Schulman, J.H. and E.M. Kilbourne. 1962. Airborne transmission of influ- enza virus infection in mice. Nature 195:1129. Selikoff, I.J., J. Churg, and E.C. Hammond. 1965. The occurrence of asbes- tosis among insulation workers in the United States. Ann. Rpt. NY Acad- emy of Science. Serati, A. and M. Wuthrich. 1969. Luftfreughtigkeit und saison Kranken- heit. Schweizerische Medizinische Wochenscrift 99:46. Shickele, E. 1947. Environment and fatal heat stroke. Military Surgeon 100:235. Smith, K.W. 1955. Pulmonary disability in asbestos workers. Archives of Industrial Health. Spengler, J.D., H.A. Burge, and H.J. Su. 1992. Biological agents and the home environment. In: Bugs, Mold and Rot (I): Proceedings of the Mois- ture Control Workshop, E. Bales and W.B. Rose (eds). 11-18. Building Thermal Envelope Council, National Institute of Building Sciences, Washington, DC. Strindehag, O., I. Josefsson, and E. Hennington. 1988. Healthy Buildings ’88, 3:611-20. Stockholm, Sweden. Streifel, A.J., D. Vesley, F.S. Rhame, and B. Murray. 1989. Control of air- borne fungal spores in a university hospital. Environ. Int. 15:221. Susskind, R.R. and M. Ishihara. 1965. The effects of wetting on cutaneous vulnerability. Archives of Environmental Health 11:529. Tancrede,M.,R.Wilson,L.Ziese,andE.A.C.Crouch.1987.Atmospheric Environment 21:2187. Teng, H.C. and H.E. Heyer, eds. 1955. The relationship between sudden changes in the weather and acute myocardial infarction. American Heart Journal 49:9. WHO. 1987. Air Quality Guidelines for Europe. European Series No. 23. WHO, Copenhagen. Yoshizawa,S.,F.Surgawa,S.Ozawo,Y.Kohsaka,andA.Matsumae.1987. Proceedings 4th International Conference on Indoor Air Quality and Cli- mate, Berlin 1:627-31. Zenz, C. 1988. Occupational safety in industry, occupational medicine, prin- ciples and practical applications. 9.20 2001 ASHRAE Fundamentals Handbook (SI) Rohles, F.H., J.A. Woods, and P.R. Morey. 1989. Indoor environmental acceptability: Development of a rating scale. ASHRAE Transactions 95(1):23-27. Samet, J.M., M.C. Marbury, and J.D. Spengler. 1987. Health effects and sources of indoor air pollution. Am. Rev. Respir. Disease 136:1486-1508. Samet, J.M. 1989. Radon and lung cancer. J. Natl. Cancer Institute 81:145. Schulman, J.H. and E.M. Kilbourne. 1962. Airborne transmission of influ- enza virus infection in mice. Nature 195:1129. Selikoff, I.J., J. Churg, and E.C. Hammond. 1965. The occurrence of asbes- tosis among insulation workers in the United States. Ann. Rpt. NY Acad- emy of Science. Serati, A. and M. Wuthrich. 1969. Luftfreughtigkeit und saison Kranken- heit. Schweizerische Medizinische Wochenscrift 99:46. Shickele, E. 1947. Environment and fatal heat stroke. Military Surgeon 100:235. Smith, K.W. 1955. Pulmonary disability in asbestos workers. Archives of Industrial Health. Spengler, J.D., H.A. Burge, and H.J. Su. 1992. Biological agents and the home environment. In: Bugs, Mold and Rot (I): Proceedings of the Mois- ture Control Workshop, E. Bales and W.B. Rose (eds). 11-18. Building Thermal Envelope Council, National Institute of Building Sciences, Washington, DC. Strindehag, O., I. Josefsson, and E. Hennington. 1988. Healthy Buildings ’88, 3:611-20. Stockholm, Sweden. Streifel, A.J., D. Vesley, F.S. Rhame, and B. Murray. 1989. Control of air- borne fungal spores in a university hospital. Environ. Int. 15:221. Susskind, R.R. and M. Ishihara. 1965. The effects of wetting on cutaneous vulnerability. Archives of Environmental Health 11:529. Tancrede,M.,R.Wilson,L.Ziese,andE.A.C.Crouch.1987.Atmospheric Environment 21:2187. Teng, H.C. and H.E. Heyer, eds. 1955. The relationship between sudden changes in the weather and acute myocardial infarction. American Heart Journal 49:9. WHO. 1987. Air Quality Guidelines for Europe. European Series No. 23. WHO, Copenhagen. Yoshizawa,S.,F.Surgawa,S.Ozawo,Y.Kohsaka,andA.Matsumae.1987. Proceedings 4th International Conference on Indoor Air Quality and Cli- mate, Berlin 1:627-31. Zenz, C. 1988. Occupational safety in industry, occupational medicine, prin- ciples and practical applications. 10.1 CHAPTER 10 ENVIRONMENTAL CONTROL FOR ANIMALS AND PLANTS ANIMALS 10.1 Animal Care/Welfare 10.2 Physiological Control Systems 10.2 Principles for Air Contaminant Control 10.5 Cattle 10.7 Sheep 10.9 Swine 10.10 Chickens 10.12 Turkeys 10.13 Laboratory Animals 10.14 PLANTS: GREENHOUSES, GROWTH CHAMBERS, AND OTHER FACILITIES 10.15 Temperature 10.15 Light and Radiation 10.17 Relative Humidity 10.19 Air Composition 10.20 Air Movement 10.20 HERMAL conditions, air quality, lighting, noise, ion concen- Ttration, and crowding are important in designing structures for animals and plants. Thermal environment influences heat dissipa- tion by animals and chemical process rates in plants. Lighting influ- ences photoperiodism in animals and plants, and photosynthesis and regulation in plants. Air quality, noise, ion concentrations, and crowding can affect the health and/or productivity of animals or plants. This chapter summarizes the published results from various research projects and provides a concept of the physiological factors involved in controlling the environment. ANIMALS Animal performance (growth, egg or milk production, wool growth, and reproduction) and their conversion of feed to useful products are closely tied to the thermal environment. For each homeothermic species, an optimum thermal environment permits necessary and desirable body functions with minimum energetic input (Figure 1A). The optimal thermal environment—in terms of an effective temperature that integrates the effects of dry-bulb tem- perature, humidity, air movement, and radiation—is less important to the designer than the range of conditions that provides acceptable animal performance, efficiency, well-being, and economic return for a given species. Figure 1A depicts this range as the zone of nom- inal losses, selected to limit losses in performance to a level accept- able to the livestock manager. Researchers have found that the zone of nominal losses corresponds to the welfare plateau (i.e., welfare is enhanced by maintaining environmental conditions within the zone of nominal losses). Milk and egg production by mature animals also shows an optional thermal environment zone, or zone of nominal losses (Figure 2). Developed from actual measurements of swine growth, Fig- ure 1B shows the relationships of energy, growth, and efficiency with air temperature. In the case of growing pigs in Figure 1B, the range of temperatures from 15 to 22°C, which includes both optimal productivity and efficiency levels, represents acceptable design conditions to achieve maximum performance and effi- ciency. Even beyond that temperature range, performance and efficiency do not markedly decline in the growing pig until near the lower critical temperature (LCT) or upper critical tempera- ture (UCT), and potential performance losses within the tempera- ture range from 10 to 25°C may be acceptable. Response relationships, as shown in Figure 1B, allow environmental selec- tion and design criteria to be based on penalties to performance (i.e, economic costs) and animal well-being—particularly when used with climatological information to evaluate risks for a par- ticular situation (Hahn et al. 1983). Choosing housing requires caution, because research indicates that factors such as group versus individual penning, feed intake, and floor type can affect the LCT by 5 K. The limits of acceptable values of the LCT and UCT depend on such effects as the species, breed, genetic characteristics of an individual animal’s age, mass, sex, level of feeding and type of feed, prior conditioning, parasites, disease, social factors such as space allocation, lactation or gestation, and physical features of the environment. The LCT and UCT vary among individuals; data reported are for group means. As a result, the limits become statistical values based on animal population and altered by time- dependent factors. Acceptable conditions are most commonly established based on temperature because an animal’s sensible heat dissipation is largely influenced by the temperature difference between the animal’s sur- face and ambient air. Humidity and air movement are sometimes included as modifiers for an effective temperature. This has been a logical development. Air movement is a secondary but influential factor in sensible heat dissipation. The importance of air velocities is species and age dependent (e.g., swine under 8 weeks of age expe- rience slower gains and increased disease susceptibility when air velocity is increased from 125 to 250 mm/s). With warm or hot ambient temperature, elevated humidity can restrict performance severely. Relative humidity has little effect on the animal’s heat dissipation during cold temperatures, and it is usu- ally only moderately important to thermal comfort during moderate temperatures. (Information is limited on such interactions, as well as on the effects of barometric pressure, air composition, and ther- mal radiation.) Animals housed in a closed environment alter air composition by reducing oxygen content and increasing carbon dioxide and vapor content. Decomposing waste products add methane, hydro- gen sulfide, and ammonia. Animal activities and air movement add microscopic particles of dust from feed, bedding, and fecal mate- rial. Generally, a ventilation rate sufficient to remove water vapor adequately controls gases. However, improper air movement pat- terns, certain waste-handling methods, and special circumstances (e.g., disease outbreak) may indicate that more ventilation is nec- essary. In many cases, ventilation is not as effective for dust con- trol as for gas control. Alternative dust control strategies may be needed. The preparation of this chapter is assigned to TC 2.2, Plant and Animal Environment, with cooperation of Committees SE-302 and SE-303 of the American Society of Agricultural Engineers. 11.1 CHAPTER 11 PHYSIOLOGICAL FACTORS IN DRYING AND STORING FARM CROPS Factors Determining Safe Storage 11.1 Moisture Measurement 11.5 Prevention of Deterioration 11.6 Drying Theory 11.8 Drying Specific Crops 11.11 HIS CHAPTER focuses on the drying and storage of grains, Toil-seeds, hay, cotton, and tobacco. However, the primary focus is on grains and oilseeds, collectively referred to as grain.Major causes of postharvest losses in these products are fungi, insects, and rodents. Substantial deterioration of grain can occur in storage. However, where the principles of good grain storage are applied, losses are minimal. Preharvest invasion of grains by storage insects is usually not a problem in the midwestern United States. Field infestations can occur in grains when they are dried in the field at warm tempera- tures during harvest. Preharvest invasion by storage fungi is possi- ble and does occur if appropriate weather conditions prevail when the grain is ripening. For example, preharvest invasion of corn by Aspergillus flavus occurs when hot weather is prevalent during grain ripening; it is, therefore, more common in the southeastern United States (McMillan et al. 1985). Invasion of wheat, soybeans, and corn by other fungi can occur when high ambient relative humidities prevail during grain ripening (Christensen and Mero- nuck 1986). However, the great majority of damage occurs during storage, due to improper conditions that permit storage fungi or insects to develop. Deterioration from fungi during storage is prevented or mini- mized by (1) reduction of grain moisture content to below limits for growth of fungi, (2) maintenance of low grain temperatures throughout the storage period, (3) chemical treatment to prevent the development of fungi or to reduce the rate of fungal growth while the grain moisture content is being lowered to a safe level, and (4) airtight storage in which initial microbial and seed respiration reduces the oxygen level so that further activity by potentially harm- ful aerobic fungi is reduced. Reduction of moisture by artificial drying is the most commonly used technique. The longer grain is stored, the lower its storage moisture should be. Some of the basic principles of grain drying and a summary of methods for predicting grain drying rate are included in the section on Drying Theory. Reduction of grain temperature by aeration is practical in tem- perate climates and for grains that are harvested during cooler sea- sons. Fans are operated when ambient temperature is lower than grain temperature. Basic information on aeration is summarized in the section on Drying Theory. Use of refrigeration systems to reduce temperature is not generally cost-effective for feed grains but may have application for higher value food grains. Chemical treatment of grain is becoming more common and is briefly described in the section on Prevention of Deterioration. When grain is placed in airtight silos, the oxygen level is rapidly reduced, and carbon dioxide increases. Although many fungi will not grow under ideal hermetic conditions, some will grow initially in imperfectly sealed bins, and this growth can reduce the feeding value of the grain for some animals. Partially emptied bins may sup- port harmful mold, yeast, and bacterial growth, which makes the grain unsuitable for human consumption. Airtight storage is briefly addressed in the section on Oxygen and Carbon Dioxide under Fac- tors Determining Safe Storage. Deterioration from insects can also be prevented by a combina- tion of reducing moisture and lowering temperature. Lowering of temperatures is best achieved by aeration with cool ambient air dur- ing cool nights and periods of cool weather. Both the use of clean storage structures and the segregation of new crop grain from car- ryover grain or grain contaminated with insects are important. If insect infestation has already occurred, fumigation is often used to kill the insects. Aeration with cold air may retard the development of the insect population. Prevention and control of insect infesta- tions are addressed in the section on Prevention of Deterioration. For information on rodent problems, see the section on Preven- tion of Deterioration. Moisture content is the most important factor determining suc- cessful storage. Although some grains are harvested at safe storage moistures, other grains (notably corn, rice, and most oilseeds) must usually be artificially dried prior to storage. During some harvest seasons, wheat and soybeans are harvested at moistures above those safe for storage and, therefore, also require drying. Sauer (1992), Brooker et al. (1992), Hall (1980), Christensen and Meronuck (1986), and Gunasekaran (1986) summarize the basic aspects of grain storage and grain drying. Chapter 22 of the 1999 ASHRAE Handbook—Applications covers crop-drying equipment and aeration systems. FACTORS DETERMINING SAFE STORAGE Moisture Content Grain is bought and sold on the basis of characteristics of repre- sentative samples. Probes or samplers, such as diverters, are used to obtain representative subsamples. Often representative subsamples must be taken from a large quantity (several tonnes) of grain. Manis (1992) summarizes sampling procedures and equipment. For safe storage, it is necessary to know the range in moisture content within a given bulk and whether any of the grain in the bulk has a moisture content high enough to permit damaging fungal growth. This range can be determined by taking probe samples from different portions of the bulk. Commonly, in large quantities of bulk-stored grain, some portions have moisture contents 2 to 3% higher than the aver- age (Brusewitz 1987). If the moisture content anywhere in the bulk is too high, fungi will grow, regardless of the average. Therefore, the moisture content of a single representative sample is not a reliable measure of storage risk or spoilage hazard. Measurement of mois- ture content and the precision of various moisture-measuring meth- ods are covered in the section on Moisture Measurement. Table 1 summarizes recommended safe storage moistures for several common grains. Note that for long-term storage, lower The preparation of this chapter is assigned to TC 2.2, Plant and Animal Environment. 12.1 CHAPTER 12 AIR CONTAMINANTS Classes of Air Contaminants 12.1 PARTICULATE CONTAMINANTS 12.2 Particulate Matter 12.2 Bioaerosols 12.5 GASEOUS CONTAMINANTS 12.7 Volatile Organic Compounds 12.9 Inorganic Gases 12.11 SPECIAL TYPES OF AIR CONTAMINANTS 12.12 Outdoor Air Contaminants 12.12 Industrial Air Contaminants 12.14 Nonindustrial Indoor Air Contaminants 12.14 Flammable Gases and Vapors 12.15 Combustible Dusts 12.16 Radioactive Air Contaminants 12.16 Soil Gases 12.17 IR IS COMPOSED mainly of gases. The major gaseous com- Aponents of clean, dry air near sea level are approximately 21% oxygen, 78% nitrogen, 1% argon, and 0.04% carbon dioxide. Normal outdoor air contains varying amounts of foreign mate- rials (permanent atmospheric impurities). These materials can arise from natural processes such as wind erosion, sea spray evap- oration, volcanic eruption, and metabolism or decay of organic matter. The natural contaminant concentrations in the air that we breathe vary but are usually lower than those caused by human activity. Man-made outdoor contaminants are many and varied, origi- nating from numerous types of human activity. Electric power- generating plants, various modes of transportation, industrial pro- cesses, mining and smelting, construction, and agriculture gener- ate large amounts of contaminants. Contaminants that present particular problems in the indoor environment include, among others, tobacco smoke, radon, and formaldehyde. Air composition may be changed accidentally or deliberately. In sewers, sewage treatment plants, tunnels, and mines, the oxy- gen content of air can become so low that people cannot remain conscious or survive. Concentrations of people in confined spaces (theaters, survival shelters, submarines) require that carbon diox- ide given off by normal respiratory functions be removed and replaced with oxygen. Pilots of high-altitude aircraft, breathing at greatly reduced pressure, require systems that increase oxygen concentration. Conversely, for divers working at extreme depths, it is common to increase the percentage of helium in the atmo- sphere and reduce nitrogen and sometimes oxygen concentrations. At atmospheric pressure, oxygen concentrations less than 12% or carbon dioxide concentrations greater than 5% are dangerous, even for short periods. Lesser deviations from normal composi- tion can be hazardous under prolonged exposures. Chapter 9 fur- ther details environmental health issues. CLASSES OF AIR CONTAMINANTS The major classes of air contaminants are particulate and gas- eous. The particulate class covers a vast range of particle sizes from dust large enough to be visible to the eye to submicroscopic particles that elude most filters. Particulates may be solid or liquid. The following traditional contaminant classifications are subclasses of particulates: • Dusts, fumes,andsmokes, which are mostly solid particulate matter, although smoke often contains liquid particles • Mists, fogs,andsmogs, which are mostly suspended liquid particles smaller than those in dusts, fumes, and smokes • Bioaerosols, including viruses, bacteria, fungal spores, and pollen, whose primary impact is related to their biological origin • Particle size definitions such as coarse or fine, visible or invisible,andmacroscopic, microscopic,orsubmicroscopic • Definitions that relate to particle interaction with the human respiratory system, such as inhalable and respirable These classes, their characteristics, units of measurement, and mea- surement methods are discussed in more detail in this chapter. The gaseous class covers chemical contaminants that can exist as free molecules or atoms in air. Molecules and atoms are smaller than particles and may behave differently as a result. This class cov- ers two important subclasses: • Gases, which are naturally gaseous under ambient indoor or outdoor conditions • Vap or s , which are normally solid or liquid under ambient indoor or outdoor conditions, but which evaporate readily Through evaporation, liquids change into vapors and mix with the surrounding atmosphere. Like gases, they are formless fluids that expand to occupy the space or enclosure in which they are con- fined. Typical gaseous contaminants, their characteristics, units of measurement, and measurement methods are discussed in detail later in this chapter. Air contaminants can also be classified according to their sources; their properties; or the health, safety, and engineering issues faced by people exposed to them. Any of these can form a convenient classification system because they allow grouping of applicable standards, guidelines, and control strategies. Most of the following classes include both particulate and gaseous contami- nants. This chapter covers the background information for these classes, while Chapter 9 deals with the applicable indoor health and comfort regulations. The classes are • Industrial air contaminants • Nonindustrial indoor air contaminants (including indoor air quality) • Flammable gases and vapors • Combustible dusts • Radioactive contaminants •Soilgases The preparation of this chapter is assigned to TC 2.3, Gaseous Air Contam- inants and Gas Contaminant Removal Equipment, in conjunction with TC 2.4, Particulate Air Contaminants and Particulate Contaminant Removal Equipment. . are particulate and gas- eous. The particulate class covers a vast range of particle sizes from dust large enough to be visible to the eye to submicroscopic particles that elude most filters. Particulates. subclasses of particulates: • Dusts, fumes,andsmokes, which are mostly solid particulate matter, although smoke often contains liquid particles • Mists, fogs,andsmogs, which are mostly suspended liquid particles. Contam- inants and Gas Contaminant Removal Equipment, in conjunction with TC 2 .4, Particulate Air Contaminants and Particulate Contaminant Removal Equipment.