The influence of ventilation on indoor/outdoor air contaminants in an office building

/pdf/laboratory-studies-of-the-temperature-dependence-of-the-54kstp2w2i.pdf

Laboratory studies of the temperature dependence of the palmes no2 passive sampler

Rising energy prices have generated a national incentive to reduce ventilation rates in buildings and thereby lower heating and cooling costs. One of the ramifications of reducing ventilation is that indoor air contaminants build up and pose a health risk to occupants. A research program being conducted to determine the extent to which low ventilation rates are compatible with good indoor air quality is described. Overall indoor air quality is influenced by air-exchange rates, types of appliances and building materials used, and occupant activities. From the numerous indoor air pollutants studied, four (carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particle-board, plywood, urea formaldehyde foam insulation, and gas appliances; and radon from soil, building materials, and ground water) are receiving considerable attention in the context of potential health risks associated with energy conservation. Field monitoring studies in energy-efficient residential buildings have demonstrated that, in some cases, these indoor-generated pollutants exceed outdoor air-quality standards in houses having air-exchange rates of less than 0.5 air changes per hour. The results of our research suggest that further studies, designed to include a broader range of infiltration rates ad occupancy conditions, are needed before establishing energy-efficient infiltration standards for residential buildings.

/pdf/the-impact-of-reduced-ventilation-on-indoor-air-quality-in-1gkpjhwjml.pdf

The impact of reduced ventilation on indoor air quality in residential buildings

When infiltration and ventilation of a building are reduced in order to achieve energy savings, indoor air quality might deteriorate. Formaldehyde and other aldehydes, important indoor air contaminants, were studied as a function of building air exchange rates in public buildings and energy-efficient research houses. Sequential gas bubbling systems were used in conjunction with a pneumatic flow control system for field sampling. Samples were collected simultaneously for formaldehyde and total aliphatic aldehydes, and were analyzed in the laboratory using modified chromotropic acid, pararosaniline and MBTH methods. At public buildings, it was found that concentrations of formaldehyde and aldehydes were about the same in indoor and outdoor air due largely to traditionally high ventilation rates in these buildings. However, it is evident that indoor air in general has higher formaldehyde and total aliphatic aldehyde levels than outdoor air. Residential buildings and office trailers, in particular, have formaldehyde and total aliphatic aldehyde concentrations that can exceed the promulgated European indoor formaldehyde standard of 120 ..mu..g/m/sup 3/ (approx. 100 ppB). Since these high air contaminant levels might have adverse health and comfort effects on building occupants, further study is needed to establish ventilation requirements for energy-efficient building designs.

https://escholarship.org/content/qt08m2897x/qt08m2897x.pdf?t=p21mo0

Indoor/outdoor measurements of formaldehyde and total aldehydes

Measurements of selected volatile organic compounds (VOCs), known as markers of emissions resulting from burning practices using natural- and synthetic biomaterials, have been carried out in major religious/ritual-indoors in India. Four different religious/ritual-indoors were selected for monitoring purposes: 1) Hindu Marriage Places (MP), 2) Muslim Holy Shrines (MG), 3) Buddhist Temples (BT), and 4) Hindu Temples (HT). One pure residential-indoor (RESID) site was also examined for comparison studies. Indoor VOCs sampling was carried out throughout the three seasons of summer, fall and winter of the calendar year of 2012–2013 in Raipur, India. VOCs samples, collected by passive sampling over a 48-h period, were analyzed using thermal desorption (TD), followed by high-resolution gas chromatographic separation and mass spectrometric detection (GC/MS). A total of 14 volatile organic compounds (n-hexane, cyclohexane, n-heptane, noctane, n-nonane, n-decane, n-undecane, styrene, o-xylene, m,p-xylene, 1,2,4-trimethyl benzene, ethylbenzene, benzene, and toluene.) were quantified. The annual mean concentrations for total VOCs (TVOCs) were 216.61 ± 75.15, 656.34 ± 220.82, 681.75 ± 219.83, 129.51 ± 45.24 and 82.67 ± 40.96 µg/m 3 for MP, MG, BT, HT and RESID respectively. The results were found to be higher than the prescribed standards and earlier reported indoor VOCs levels. Indoor/outdoor ratios (I/O), correlation analyses, seasonal variations and indoor/outdoor contributions to the measured levels are also investigated.

/pdf/indoor-vocs-from-religious-and-ritual-burning-practices-in-28duc1tpih.pdf

Indoor VOCs from Religious and Ritual Burning Practices in India

A mobile laboratory for research and development studies of ventilation requirements and energy utilization in residential and commercial buildings was designed and fabricated. The mobile laboratory contains sampling, calibrating, and monitoring systems to measure the concentration of CO, CO/sub 2/, NO, NO/sub 2/, NO/sub x/, O/sub 3/, and SO/sub 2/, and infiltration rates can be monitored continuously using a tracer gas system in which the tracer is injected into the room, mixed with room air, and monitored.

/pdf/design-of-a-mobile-laboratory-for-ventilation-studies-and-43mph2wvns.pdf

C.D. Hollowell

Papers

The impact of reduced ventilation on indoor air quality in residential buildings

Design of a mobile laboratory for ventilation studies and indoor air pollution monitoring. [Residences and commercial buildings]