Effects of energy retrofits on Indoor Air Quality in multifamily buildings.

We assessed 45 multifamily buildings (240 apartments) from Finland and 20 (96 apartments) from Lithuania, out of which 37 buildings in Finland and 15 buildings in Lithuania underwent energy retrofits. Building characteristics, retrofit activities, and energy consumption data were collected, and Indoor Air Quality (IAQ) parameters, including carbon monoxide (CO), nitrogen dioxide (NO2 ), formaldehyde (CH2 O), selected volatile organic compounds (benzene, toluene, ethylbenzene, and xylenes (BTEX), radon, and microbial content in settled dust were measured before and after the retrofits. After the retrofits, heating energy consumption decreased by an average of 24% and 49% in Finnish and Lithuanian buildings, respectively. After the retrofits of Finnish buildings, there was a significant increase in BTEX concentrations (estimated mean increase of 2.5 µg/m3 ), whereas significant reductions were seen in fungal (0.6-log reduction in cells/m2 /d) and bacterial (0.6-log reduction in gram-positive and 0.9-log reduction in gram-negative bacterial cells/m2 /d) concentrations. In Lithuanian buildings, radon concentrations were significantly increased (estimated mean increase of 13.8 Bq/m3 ) after the retrofits. Mechanical ventilation was associated with significantly lower CH2 O concentrations in Finnish buildings. The results and recommendations presented in this paper can inform building retrofit studies and other programs and policies aimed to improve indoor environment and health.

Impacts of exhaled aerosol from the usage of the tobacco heating system to indoor air quality: A chamber study.

Aerosol particle, carbonyl, and nicotine concentrations were analysed as pollutants affecting indoor air quality during the usage of electrically-heated tobacco product - the Tobacco Heating System (THS). Quantitative experimental variables included THS use intensity as number of parallel users (1, 3, or 5), distance to the bystander (0.5, 1, or 2 m), as well as environmental conditions in a chamber: ventilation intensity as air changes per hour (0.2, 0.5, or 1 h-1), and relative humidity (RH, 30, 50 or 70%). The real-time particle number (PNC), CO and CO2 concentration, as well as off-line acetaldehyde, formaldehyde, nicotine, and 3-ethenylpyridine concentration was measured during and after the active usage. Use of THS resulted in a statistically significant increase of several analytes including nicotine, acetaldehyde, PM2.5, and PNC as compared to the background. The obtained levels were significantly lower (approximately 16, 8, 8 and 28 times for nicotine, acetaldehyde, PNC and PM2.5, respectively) compared to the levels resulting from conventional cigarette (CC) smoking under identical conditions. The maximum 30 min concentration of PNC (4.8 × 105 #/cm3), as well as maximum concentration of PNC (9.3 × 106 #/cm3) suggest that the intensive use of THS in a confined space with limited ventilation might cause substantially elevated aerosol concentrations, although these particles appeared as highly volatile ones and evaporated within seconds. Generally, the usage intensity (number of simultaneous users) prevailed as the most important factor positively affecting pollutant variations; another important factor was the distance to bystander.

Characterization of the Spatial and Temporal Dispersion Differences Between Exhaled E-Cigarette Mist and Cigarette Smoke.

INTRODUCTION: There are fundamental differences between electronic cigarettes (e-cigarettes) and conventional cigarette product categories with regards to potential environmental exposures, notably that e-cigarettes do not contain tobacco or generate side-stream emissions. Here we assess the spatial and temporal patterns of exhaled e-cigarette aerosol at a bystander's position, and compare it with conventional cigarette smoke emissions. METHODS: Smokers were asked to use e-cigarettes or smoke conventional cigarettes in a room-simulating chamber. Volunteers used the products at different distances from a heated mannequin, representing a bystander, and under different room ventilation rates. Aerosol particle concentrations and size distributions at the bystander's position were measured. RESULTS: For both product categories, the particle concentrations registered following each puff were in the same order of magnitude. However, for e-cigarettes the particle concentration returned rapidly to background values within seconds; for conventional cigarettes it increased with successive puffs, returning to background levels after 30-45 minutes. Unlike for the e-cigarette devices tested, such temporal variation was dependent on the room ventilation rate. Particle size measurements showed that exhaled e-cigarette particles were smaller than those emitted during smoking conventional cigarettes and evaporated almost immediately after exhalation, thus affecting the removal of particles through evaporation rather than displacement by ventilation. CONCLUSIONS: Significant differences between emissions from the tested e- and conventional cigarettes are reported. Exhaled e-cigarette particles are liquid droplets evaporating rapidly; conventional cigarette smoke particles are far more stable and linger. IMPLICATIONS: • Several factors potentially influencing particle behavior after exhalation of e-cigarette aerosols or emitted during smoking conventional cigarettes were studied.• Differences in particle size between those exhaled following use of e-cigarettes and those emitted during smoking of conventional cigarettes were observed.• E-cigarette particle concentrations decreased rapidly following exhalation due to evaporation.• The removal of particles following smoking conventional cigarettes was much slower and was dependent on the room ventilation rate.

Occupant satisfaction with indoor environmental quality and health after energy retrofits of multi-family buildings: Results from INSULAtE-project.

BACKGROUND: Driven by climate change mitigation, EU countries are committed to improve energy efficiency of their building stock by implementing the energy performance of buildings directive (EPBD). Should higher energy efficiency result in better indoor environmental quality (IEQ), this policy could also be seen as an opportunity to improve public health across Europe. OBJECTIVES: This paper focuses on the assessment of the effects of energy retrofits on occupant satisfaction with IEQ and health in multifamily buildings. METHODS: Data on occupant satisfaction with IEQ and health were collected from the occupants of 39 Finnish and 15 Lithuanian multifamily buildings (an average of five apartments per building, one adult per apartment) both before and after energy retrofits (such as improving thermal insulation, windows, heating and/or ventilation systems). Parallel to the data collected from the occupants, data on several IEQ parameters, including temperature, temperature factor, and air change rate, were collected from their apartments. Moreover, data from seven Finnish and five Lithuanian non-retrofitted control buildings were collected according to the same protocol. RESULTS: Occupant satisfaction regarding indoor temperature was associated with both retrofit status (OR 5.3, 95% CI 2.6-11.0) and measured IEQ parameters (indoor temperature OR 1.4 per 1 °C increase, temperature factor OR 1.1 per 1% increase, and air change rate OR 5.6 per 1/h increase). Additional positive associations were found between retrofit status and occupants reporting absence of upper respiratory symptoms (OR 1.8, 95% CI 1.1-2.9) as well as not missing work or school due to respiratory infections (OR 4.1, 95% CI 1.2-13.8), however, these associations were independent of the measured IEQ parameters. CONCLUSIONS: There seems to be a strong subjective component related to the observed changes in occupant satisfaction with IEQ and health as a result of energy retrofitting in buildings. Further studies are needed to verify the actual mechanisms, as well as possible long term effects.

Indoor thermal environment, air exchange rates, and carbon dioxide concentrations before and after energy retro fits in Finnish and Lithuanian multi-family buildings.

Impacts of energy retrofits on indoor thermal environment, i.e. temperature (T) and relative humidity (RH), as well as ventilation rates and carbon dioxide (CO2) concentrations, were assessed in 46 Finnish and 20 Lithuanian multi-family buildings, including 39 retrofitted case buildings in Finland and 15 in Lithuania (the remaining buildings were control buildings with no retrofits). In the Finnish buildings, high indoor T along with low RH levels was commonly observed both before and after the retrofits. Ventilation rates (l/s per person) were higher after the retrofits in buildings with mechanical exhaust ventilation than the corresponding values before the retrofits. Measured CO2 levels were low in vast majority of buildings. In Lithuania, average indoor T levels were low before the retrofits and there was a significant increase in the average T after the retrofits. In addition, average ventilation rate was lower and CO2 levels were higher after the retrofits in the case buildings (N=15), both in apartments with natural and mixed ventilation. Based on the results, assessment of thermal conditions and ventilation rates after energy retrofits is crucial for optimal indoor environmental quality and energy use.

Filter media properties of mineral fibres produced by plasma spray.

The purpose of this study was to determine the properties of fibrous gas filtration media produced from mineral zeolite. Fibres were generated by direct current plasma spray. The paper characterizes morphology, chemical composition, geometrical structure of elementary fibres, and thermal resistance, as well as the filtration properties of fibre media. The diameter of the produced elementary fibres ranged from 0.17 to 0.90 µm and the length ranged from 0.025 to 5.1 mm. The release of fibres from the media in the air stream was noticed, but it was minimized by hot-pressing the formed fibre mats. The fibres kept their properties up to the temperature of 956°C, while further increase in temperature resulted in the filter media becoming shrunk and brittle. The filtration efficiency of the prepared filter mats ranged from 95.34% to 99.99% for aerosol particles ranging in a size between 0.03 and 10.0 µm. Unprocessed fibre media showed the highest filtration efficiency when filtering aerosol particles smaller than 0.1 µm. Hot-pressed filters were characterized by the highest quality factor values, ranging from 0.021 to 0.064 Pa(-1) (average value 0.034 Pa(-1)).

Assessment of indoor environmental quality in existing multi-family buildings in North-East Europe.

Sixteen existing multi-family buildings (94 apartments) in Finland and 20 (96 apartments) in Lithuania were investigated prior to their renovation in order to develop and test out a common protocol for the indoor environmental quality (IEQ) assessment, and to assess the potential for improving IEQ along with energy efficiency. Baseline data on buildings, as well as data on temperature (T), relative humidity (RH), carbon dioxide (CO2), carbon monoxide (CO), particulate matter (PM), nitrogen dioxide (NO2), formaldehyde, volatile organic compounds (VOCs), radon, and microbial content in settled dust were collected from each apartment. In addition, questionnaire data regarding housing quality and health were collected from the occupants. The results indicated that most measured IEQ parameters were within recommended limits. However, different baselines in each country were observed especially for parameters related to thermal conditions and ventilation. Different baselines were also observed for the respondents' satisfaction with their residence and indoor air quality, as well as their behavior related to indoor environment. In this paper, we present some evidence for the potential in improving IEQ along with energy efficiency in the current building stock, followed by discussion of possible IEQ indicators and development of the assessment protocol.

Indoor and outdoor concentrations of fine particles, particle-bound PAHs and volatile organic compounds in Kaunas, Lithuania.

This complex study presents indoor and outdoor levels of air-borne fine particles, particle-bound PAHs and VOCs at two urban locations in the city of Kaunas, Lithuania, and considers possible sources of pollution. Two sampling campaigns were performed in January-February and March-April 2009. The mean outdoor PM(2.5) concentration at Location 1 in winter was 34.5 ± 15.2 µg m(-3) while in spring it was 24.7 ± 12.2 µg m(-3); at Location 2 the corresponding values were 36.7 ± 21.7 and 22.4 ± 19.4 µg m(-3), respectively. In general there was little difference between the PM concentrations at Locations 1 and 2. PM(2.5) concentrations were lower during the spring sampling campaign. These PM concentrations were similar to those in many other European cities; however, the levels of most PAHs analysed were notably higher. The mean sum PAH concentrations at Locations 1 and 2 in the winter campaign were 75.1 ± 32.7 and 32.7 ± 11.8 ng m(-3), respectively. These differences are greater than expected from the difference in traffic intensity at the two sites, suggesting that there is another significant source of PAH emissions at Location 1 in addition to the traffic. The low observed indoor/outdoor (I/O) ratios indicate that PAH emissions at the locations studied arise primarily from outdoor sources. The buildings at both locations have old windows with wooden frames that are fairly permissive in terms of air circulation. VOC concentrations were mostly low and comparable to those reported from Sweden. The mean outdoor concentrations of VOC's were: 0.7 ± 0.2, 3.0 ± 0.8, 0.5 ± 0.2, 3.5 ± 0.3, and 0.2 ± 0.1 µg m(-3), for benzene, toluene, ethylbenzene, sum of m-, p-, o-xylenes, and naphthalene, respectively. Higher concentrations of VOCs were observed during the winter campaign, possibly due to slower dispersion, slower chemical transformations and/or the lengthy "cold start" period required by vehicles in the wintertime. A trajectory analysis showed that air masses coming from Eastern Europe carried significantly higher levels of PM(2.5) compared to masses from other regions, but the PAHs within the PM(2.5) are of local origin. It has been suggested that street dust, widely used for winter sanding activities in Eastern and Central European countries, may act not only as a source of PM, but also as source of particle-bound PAHs. Other potential sources include vehicle exhaust, domestic heating and long-range transport.