Air problems

Provides for the assessment and mitigation of asbestos hazards in schools Investigates GSAs-ontroUed buildings for indoor air problems... 

M. Meckler and J. E. Janssen, in Engineertng Solutions to Indoor Air Problems Proceedings of the ASHRAE Conference JAQ 88, 130-147, Atlanta, GA ASHRAE, 1988. 

Table 2-12A is convenient for most air problems, noting that both free air (60°F and 14.7 psia) and compressed air at 100 psig and 60°F are indicated. The corrections for other temperatures and pressures are also indicated. Figure 2-37 is useful for quick checking. However, its values are slightly higher (about 10 percent) than the rational values of Table 2-11, above about 1000 cfm of free air. Use for estimating only. 

Bayer C. 1995. Beware of fungus among us Emissions from mold and fungus may be culprits in indoor air problems. Georgia Tech Research News, August 3, 1995. Atlanta GA Institute of... 

Illustrative Example 18.2 Estimating Molecular Diffusivity in Air Problem Estimate the molecular diffusion coefficient in air, >,a, ofCFC-12 (see Illustrative Example 18.1) at 25°C (a) from the mean molecular velocity and the mean free path, (b) from the molar mass, (c) from the molar volume, (d) from the combined molar mass and molar volume relationship by Fuller (Eq. 18-44), (e) from the molecular diffusivity of methane. 

Since then much research has been done on the possible contributions of VOCs to indoor air problems. Results of human exposure experiments were reviewed by Molhave (2000b, 2001). Several controlled experiments were performed in laboratories around the world in which human responses to VOCs known as indoor air pollutants were investigated to test among other things, to what extent low level exposures to such VOCs might contribute to the prevalence of complaints in nonindustrial buildings. This chapter summarizes some of the findings in 12 of these controlled experiments. 

Andersson, K. (1998) Epidemiological approach to indoor air problems. Indoor Air, 8, (Suppl. 4), 32-9. 

Winfield, M. (1987) A case history odour and health problems in a Texas public school building. Proceedings of IAQ 87 Practical Control if Indoor Air Problems, ASHRAE, Atlanta, pp. 111-18. 

Spray aerators—water sprayed into the air. Problems inclnde evaporation and freezing. 

Air may not immediately be thought of as a contaminant, but the presence of air in its various forms may have an impact on the ability of the lubricant to perform its design function. Almost all lubricating oil systems contain some air. Air is found in four phases free air, dissolved air, entrained air, and foam. Free air is trapped in a system, such as an air pocket in a hydraulic line, and may have minimal contact with the fluid. It can be a contributing factor to other air problems when lines are not bled properly during equipment startup and free air is drawn into circulating oils. 

The following definitions provide a common understanding for terminology used in describing different types of foam, air problems in stock systems and chanical additive functions ... 

Defoamer Chemical additive to control foam and treat existing entrained air problems Deaerator/antifoam Chemical additive to prevent build-up of entrained air EBS Ethylenebis(stearamide) wax, very hydrophobic defoamer component Silicone The most hydrophobic component used in defoamer formulations, may also be identified as siloxane technology... 

Radon exposure is typically an indoor air problem. Radon and other gases in the rock or soil below a building rise and eventually force themselves into the building through extremely small cracks and pores in the foundation, floors, or walls. 

We have illustrated the model predictions by evaluating two-phase ammonia clouds released in dry and moist air. The numerical test cases are identical to those in Kukkonen et al. (1993), which presents a comparison of the model AERCLOUD and the thermodynamical submodel of the heavy cloud dispersion program DRIFT (Webber et al., 1992). DRIFT embodies the homogeneous equilibrium model, while AERCLOUD allows also for thermodynamic nonequilibrium effects. Both models will cope with ammonia interactions with moist air as well as with the simpler dry air problem. 

The presence of bubbles could be due to air alone or moisture, plastic surface agents or volatiles, degradation, or the use of contaminated regrind. With molds such as those used for injection, compression, casting, or reaction injection, air or moisture in the mold cavity will be the culprit. So the first step to resolving a bubble or air problem is to be sure what problem exists. A logical troubleshooting approach can be used. 

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