Gregory W. Traynor

Indoor air pollution due to emissions from wood-burning stoves

Four wood-burning stoves, three airtight and one non-airtight, were operated in a single-floor 236-m/sup 3/ residence and tested for indoor pollutant emissions. Results showed the airtight stoves emitted minor amounts of carbon monoxide and respirable suspended particles during door-opening operations, while the nonairtight stove continuously injected pollutants indoors under certain operating conditions. During airtight stove operation, carbon monoxide levels reached a maximum of 4 ppm, while average total suspended particulate levels ranged from 24 to 71 ..mu..g/m/sup 3/. During normal nonairtight stove operation, carbon monoxide levels reached a maximum of 8 ppm, while total suspended particulate levels ranged from 30 to 650/sup +/g/m/sup 3/. Outdoor carbon monoxide levels were 1.1 ppm or less, and outdoor particulate levels ranged from 7 to 31 ..mu..g/m/sup 3/. Five polycyclic aromatic hydrocarbons, including benzo(a)pyrene, were measured in the collected particulate samples, and the results are reported. Source strengths for carbon monoxide, total suspended particles, and five polycyclic aromatic hydrocarbons are reported. 26 references, 4 figures, 5 tables.

TECHNIQUE FOR DETERMINING POLLUTANT EMISSIONS FROM A GAS-FIRED RANGE

Abstract Laboratory measurements of pollutant emissions from a gas-fired range have shown that carbon monoxide, nitric oxide, nitrogen dioxide, sulfur dioxide, formaldehyde and respirable particles were all emitted during the combustion process. Carbon was found to be the dominant element of the respirable particles emitted. A mathematical indoor air quality model was applied to our laboratory studies to calculate pollutant emission rates per caloric value of fuel consumed. The model was also used to calculate the temporal profile of the indoor pollution concentrations as well as to determine indoor pollutant decay rates from mechanisms other than air infiltration. Comparisons of measured and calculated data showed good agreement, and suggests that this model may be useful for determining pollutant emissions from a wide variety of other sources, for estimating pollution levels in other indoor environments, and for evaluating pollutant control strategies.

Indoor Air Pollution Due to Emissions from Unvented Gas-Fired Space Heaters

Operation of an unvented combustion appliance indoors can elevate pollutant concentrations Under laboratory conditions, oxygen consumption rates and pollutant emission rates of CO, CO2, NO, NO2, HCHO and submicron suspended particles emitted from eight unvented gas-fired space heaters operated with well adjusted air shutters at partial and full fuel consumption rates were determined in a 27-m3 chamber. Emission rates were also determined for some heaters operating under poorly tuned conditions. Four of the eight heaters were subsequently tested in a 240-m3 research house with 0.36-1.14 air changes per hour. Based on measurements near steady state, steady state pollutant and oxygen levels were projected: 1930-11,100 ppm for CO2, 1.0-26 ppm for CO (under well-tuned conditions), 0.40-1.46 ppm for NO2, and 19.1-20.7% for O2. Concentrations of CO2, CO, and NO2 sometimes exceeded outdoor or occupational guidelines. Analysis showed that CO, NO, and NO2 emission rates can vary with time and that, while short-term...

POLLUTANT EMISSION RATES FROM INDOOR COMBUSTION APPLIANCES AND SIDESTREAM CIGARETTE SMOKE

Particulate and gaseous emissions from indoor combustion appliances and smoking can elevate the indoor concentrations of various pollutants. Indoor pollutant concentrations resulting from operating one of several combustion appliances, or from sidestream tobacco smoke, were measured in a 27-m3 environmental chamber under varying ventilation rates. The combustion appliances investigated were gas-fired cooking stoves, unvented kerosene-fired space heaters, and unvented natural-gas-fired space heaters. Results showed elevated levels of carbon dioxide, carbon monoxide, nitric oxide, nitrogen dioxide, formaldehyde, and suspended particles from one or more of the pollutant sources investigated. Our findings suggest that, of the sources examined in this study, nitrogen dioxide from combustion appliances and particles from sidestream cigarette smoke are the most serious contaminants of indoor air, if we use existing standards and guidelines as the criteria. An emission rate model was used to quantify the strengths of the pollutant sources, which are reported in terms of the mass of pollutant emitted per energy unit of fuel consumed (in the case of gas and kerosene appliances) and per mass of tobacco combusted (in the case of smoking).

The effects of ventilation on residential air pollution due to emissions from a gas-fired range

Abstract The use of indoor combustion appliances can cause an increase in the levels of many different pollutants. The work presented here shows the usefulness of a model for extrapolating environmental chamber results on pollutant emissions from combustion appliances to determine indoor pollutant concentrations in actual residences. In addition, the effects of infiltration, whole-house ventilation, and spot ventilation on pollutant levels are investigated. The results show that a range hood is the most effective means of removing pollutants emitted from a gas-fired range; removal rates varied from 60% to 87%.

Indoor air pollution and inter-room pollutant transport due to unvented kerosene-fired space heaters

Abstract Two kerosene-fired space heaters, one white-flame convective and one blue-flame radiant, were operated in the master bedroom and living room of an unoccupied house (elevation: 1800 m) under several simulated use conditions. Tests were conducted in the master bedroom with the bedroom door and bedroom window open and closed. The heaters were operated until an 8 °C temperature rise was achieved in the room. Increases in bedroom concentrations of CO, CO 2 , NO, NO 2 , and O 2 are reported. The increases in CO 2 levels ranged from 2440 to 5440 mL/m 3 (ppm) while the increases in NO 2 levels ranged from 0.12 to 0.60 mL/m 3 (ppm). The NO 2 emission rate from the convective heater was reduced at the high altitude location as compared with previous emission rate measurements conducted near sea level with the same heater. In addition, inter-room pollutant transport rates are reported for bedroom tests conducted with the window closed. While inter-room pollutant transport rates were less than 10 m 3 with the bedroom door closed (opening area less than 100 cm 2 ), they ranged from 16 m 3 /h to 53 m 3 /h with the bedroom door open 2.5 cm (opening = 520 cm 2 ), and ranged from 190 to 3400 m 3 /h with the door fully open (opening area = 15,000 cm 2 ). Continuous emission rate data are reported for tests conducted with the heater in the living room.

FIELD MONITORING DESIGN CONSIDERATIONS FOR ASSESSING INDOOR EXPOSURES TO COMBUSTION POLLUTANTS

Abstract Laboratory and controlled field studies of indoor air quality (IAQ) have characterized pollutant emission rates from combustion sources and have measured other key indoor air pollution parameters such as air exchange rates and indoor reactivity rates for the houses investigated. In addition, several field studies have attempted to measure, with varying degrees of success, pollutant exposures, indoor pollutant concentrations, and other parameters in large populations. To date, there exists no comprehensive strategy for assessing distributions of exposures to combustion pollutants and distributions of factors that affect such exposures in large populations. This paper outlines important parameters that affect combustion-related indoor air pollution concentrations and exposures, delineates weaknesses in our current understanding of exposures and field sampling methodologies, and mentions important considerations in planning appropriate field sampling strategies.

Pollutant emission rates from a radiant fiber-matrix gas burner.

Previous studies have quantified the emissions of trace constituents from unvented gas and kerosene space heaters, including CO, NO, NO[sub 2], formaldehyde, and respirable particles. The emission rates of these vary with heater technology such as burner design and operating conditions. Recent advances in infrared radiant gas burner technology have led to the development of a radiant fiber-matrix gas burner that exhibits lower emissions of some of these constituents. The development of a suitable configuration may result in a heater which can be used in residential and commercial gas appliances where reduced CO and NO[sub 2] are desired. This report presents laboratory measurements of pollutant emission rates from a prototype radiant fiber-matrix gas burner under several different operating conditions. Emission rates were quantified for CO, NO, NO[sub 2] and oxides of nitrogen (NO[sub x] = NO + NO[sub 2]) reported as nitrogen [N(of NO[sub x])]. 7 refs., 1 fig., 2 tabs.