This study evaluated the technical feasibility of the application of TiO2 photocatalysis for the removal of volatile hydrocarbons(VHC) at low ppb concentrations commonly associated with non-occupational indoor air quality issues. A series of experiments was conducted to evaluate five parameters (relative humidity (RH), hydraulic diameter (HD), feeding type (FT) of VHC, photocatalytic oxidation (PCO) reactor material (RM), and inlet port size (IPS) of PCO reactor) for the PCO destruction efficiencies of the selected target VHC. None of the target VHC presented significant dependence on the RH, which are inconsistent with a certain previous study that reported that under conditions of low humidity and a ppm toluene inlet level, there was a drop in the PCO efficiency with decreasing humidity. However, it is noted that the four parameters (HD, RM, FT and IPS) should be considered for better VHC removal efficiencies for the application of TiO2 photocatalytic technology for cleansing non-occupational indoor air. The PCO destruction of VHC at concentrations associated with non-occupational indoor air quality issues can be up to nearly 100%. The amount of CO generated during PCO were a negligible addition to the indoor CO levels. These abilities can make the PCO reactor an important tool in the effort to improve non-occupational indoor air quality.

This study was carried out to improve the interior environment by adjusting air of interior landscape. Unlike the methodology of removing interior contaminants through absorption of contaminants from existing interior plants, it introduced methodology of removing CO2 from the interior landscape plants. It examined the amount of m generated and absorbed by plants during 6 hours in sealed chamber. As a result of chamber test of 30 plants I capability of generating CO2 in Fatsia japonica, Monstera deliciosa, Pltilodendron selloum, Schefflera arboricola, Dracaena fragrans 'Massangeana', Ficus benjamiana, etc 30 indoor plants was 17.84 -2.34 ㎍/cm2. It was assumed that high type plants was needed 2-3 plants room, lower type plants was neded 20-30 flower pots as excellent plants for indoor air purification in order to remove CO2 in 20m3 sealed. Therefore it found that indoor plants was applied for suppling fresh air and sustaining indoor air quality safitily and continuously.

Under controlled conditions in an environmental chamber, 24 experiments were performed to compare the ability of a Variable-Air-Volume/Bypass Filtration System(VAV/BPFS) to remove indoor pollutants and to conserve energy with the ability of conventional Variable Air Volume(VAV) system. The specific conclusions of this paper were; first, the VAV/BPFS was more efficient than the VAV system in removing particulate matter, TVOC, and target VOCs. The total effective removal rate of PM for the VAV/BPFS was two times as high as that of the VAV system. The total effective removal rate of TVOC for the VAV/BPFS was 20 percent higher than that of the VAV system. Also each target VOC concentration was reduced by using the VAV/BPFS. Second, clean air delivery rate was increased by using VAV/BPFS due to additional filtration rate. Otherwise, the VAV/BPFS decreased outdoor supply air rate above 25 percent relative to the rate of VAV system. Third, total energy consumption by the VAV/BPFS was lower than that of the VAV system during the period with indoor thermal load, occupied time. The energy saving of the VAV/BPFS ranged from 11 to 16 percent. The VAV/BPFS improves indoor air quality more efficiently than the VAV system, and it reduced energy consumption. Retrofitting the VAV system with the VAV/BPFS was easy. The use of VAV/BPFS is, therefore, recommended for buildings with VAV system as well as for buildings at designing stage.

The well-mixed room model has been traditionally used to predict the concentrations of contaminants in indoor environments. However, this is inappropriate because the flow fields in many indoor environments distribute contaminants non-uniformly, due to imperfect air mixing. Thus, some means used to describe an imperfectly mixed room are needed. The simplest model that accounts for imperfect air mixing is a two-zone model. Therefore, this study on development of computer program for the two-zone model is carried out to propose techniques of estimating the concentration of contaminants in the room. To do this, an important consideration is to divide a room into two-zone, i.e. the lower and upper zone assuming that the air and contaminants are well mixed within each zone. And between the zones the air recirculation is characterized through the air exchange parameter. By this basic assumption, the equations for the conservation of mass are derived for each zone. These equations are solved by using the computational technique. The language used to develope the program is a VISUAL BASIC. The value of air exchange coefficient(f_12) is the most difficult to forecast when the concentrations of contaminants in an imperfectly mixed room are estimated by the two-zone model. But, as the value of f_12 increases, the air exchange between each zone increases. When the value of f_l2, is approximately 15, the concentrations in both zone approach each other, and the entire room may be approximately treated as a single well-mixed room. Therefore, this study is available for designing of the ventilation to improve the air quality of indoor environments. Also, the two-zone model produces the theoretical base which may be extended to the theory for the multi-zone model, that will be contributed to estimate the air pollution in large enclosures, such as shopping malls, atria buildings, airport terminals, and covered sports stadia.

The oil crisis of the 1970s and the rise in oil prices motivated people to implement energy conservation strategies. Buildings were fitted with additional insulation and reduced ventilation rates. The reduction of mechanical and natural ventilation rate led to increases in indoor pollutant concentrations which resulted in increased health risks from indoor exposure to pollutants. The variable-air-volume/bypass filtration system(VAV/BPFS) is a variation of the conventional VAV systems, The VAV/BPFS is an electronically controlled system that provides cost-effective thermal comfort and acceptable indoor air quality. Under controlled conditions in a chamber, a series experiments were performed to compare the ability of a VAV/BPFS to remove indoor aerosol concentration and to reduce energy consumption with that ability of conventional VAV system. Results show that the VAV/BPFS increases the effective ventilation rate and removes indoor air pollutant, and maintains acceptable indoor air quality without sacrificing energy consumption.

The purpose of this study was to quantitatively determine the indoor infiltration of pollutants of outdoor origin. The relationship between indoor and outdoor air is dependent, to a large extent, on the rate of air exchange between these two environments. Mean indoor/outdoor ratios measured from this study were: 0.70 for HNO_3; 1.60 for HNO_2; 0.56 for SO_2; 1.30 for NH_3; 0.96 for PM_2.5(d_p<2.5μm); 0.89 for SO_4^2-; 0.87 for NO_3^- and 0.79 for NH_4^+. Mean indoor concentrations for PM_2.5, SO_4^2-, HNO_3, NO_3^- and NH_4^+ were similar to outdoor levels. Indoor HNO_2 and NH_3 values were higher than outdoors. However, the indoor level of SO_2 was lower than ambient level.

Chloroform present in the swimming water disinfected with sodium hypochlorite is released to the air of swimming pools. The air chloroform concentrations were measured in two swimming pools A and B which applied both sodium hypochlorite and ozone. Their mean concentrations are 28.0 ㎎/㎥ and 33.6 ㎍/㎥ in the swimming pools A and B, respectively. On the other hand, the mean water chloroform concentrations in the swimming pools A and B were 23.9 ㎍/ℓ and 19.5 ㎍/ℓ, respectively. The air chloroform concentrations were lower in the swimming pools A and B than those reported by previous studies abroad employed the swimming pools which applied sodium hypochlorte only for water disinfection. The water chloroform concentrations were also lower in this study than in the previous studies. The relationship between the air and water chloroform concentrations measured in this study was significant with p=0.002 and R^2=O.42. At similar time to the indoor air sampling, outdoor air samples were collected at two sites near each of the swimming pools A and B. The mean outdoor air chloroform concentrations near the swimming pools A and B were 0.41 ㎍/㎥ and 0.16 ㎍/㎥, respectively. The outdoor air chloroform concentrations measured in this study were equal to or lower than those reported by previous studies abroad. The chloroform dose inhaled for a typical one-hour swim was estimated to be 25.9 ㎍ per person, corresponding to a specific 0.37 ㎍/㎏ body weight. for a reference 70 ㎏ male adult, while the inh lation dose of chloroform from the outdoor air was estimated to be 5.6 ㎍ per person per day, corresponding to a specific 0.08 ㎍/㎏/day for the same reference male adult.

To perform a long-term ambient sampling study at a residential site, an air sampler was constructed to collect 24-hour integrated air samples suitable for the volatile organic compounds (VOCs) analysis. It includes an esthetically acceptance due to proximity to homes, as well as providing the required sampling specifications. The VOCs sampler accomodates four 5/8 stainless steel(SS) traps packed with adsorbent(Tenax) and is capable of four flow rates in the range of 5 to 50 cc/min. Sintered metal filters(10 micrometer) were directly connected to the inlet of the trap adapters. Additional specifications include: 1) constructed of organically inert materials. 2) weatherproof, 3) battery operated, 4) collecting of VOCs at a breathing zone level, , and 5) quiet operation with micro diaphragm pumps wrapped by the sponge. The pump/battery system was separated from the sampling shelter. Sound levels measured for this system were below permissible sound levels (NJDEP) at a residential site. The sampler has been successfully operated at both ground level in a residential area and on the roof of a one story elementary school.