Ventilation Guidelines Research Articles

The Japanese Respiratory Society Noninvasive Positive Pressure Ventilation (NPPV) Guidelines (second revised edition).

The Japanese Respiratory Society Noninvasive Positive Pressure Ventilation (NPPV) Guidelines (second revised edition).

Smoke spreading analysis from an experimental subway scale model

The aim of this study is to experimentally investigate buoyancy-induced upward flow interaction with forced convection by mechanical ventilation. We consequently tried to determine optimal ventilation strategy in case of fire arising in a confined subway station. To do so, a subscale approach was developed and measurements from Picture Imaging Velocimetry and thermal field investigations were carried out to provide comprehensive flow field analysis. The flow patterns involved have been described for several geometric configurations i.e. first without and then with passenger staircases. In staircases, limits of the momentum ratio determining presence of the stack phenomenon were identified for two staircase configurations. A need for compromise between smoke-free staircases and a globally stratified platform environment was underscored. Extraction tends to decrease by 22% the safety height parameter in the station, but a concomitant 50% ventilation mass flow rate increase ensures that the two passenger accesses will be smoke-free. The results of this study correspond to the existing guidelines for prevention and ventilation in case of underground station fire.

Study of Securing Required Ventilation Rates and Improving Mechanical Ventilation Systems for Underground Parking Lots

This study presents ventilation guidelines for underground parking lots for building designers. The guidelines are classified into those for natural ventilation and those for mechanical ventilation. CONTAMW was used to study the natural ventilation of underground parking lots. Computational fluid dynamics (CFD) was used to study the ventilation efficiency of the mechanical ventilation system. The study results are as follows: 1) Underground parking lots had the lowest seasonal natural ventilation rates in the period between winter and summer when the difference between the indoor and outdoor temperatures was small. 2) In an apartment building, the required ventilation rate for the underground parking lots could be secured for up to 40 parked cars by natural ventilation alone, regardless of season. 3) In business facilities, the required ventilation rate could be secured for up to 38 parked cars when the difference between the indoor and outdoor temperatures was 3°C in the period between winter and summer. 4) In the case of the mechanical ventilation of the underground parking lots, the best ventilation efficiency was observed with a downward air supply system of jet fans in combination with an air supply near the floor and an air exhaust near the ceiling.

Ventilation guidelines for controlling smoke, dust, droplets and waste heat: Four representative case studies in Chinese industrial buildings

Four representative studies were selected to investigate industrial ventilation guidelines for controlling smoke, dust, droplets and waste heat. In the first case, exhaust hoods were designed to improve the smoke capture rates during the pouring process. It demonstrated that constructing the exhaust hoods with large aspect ratio and contain volume could improve the capture rates. The second case addresses the detailed characteristics of dust generated from bulk materials transport. The results indicated that the dust emission rate could be reduced by decreasing the drop height and the percentage of 0–10μm in the materials in the transitive regime while by decreasing the percentage of 0–10μm in the materials in the dispersive regime. The third case addresses the movement and control of water droplets from an opening tank. It showed that the droplet diameter was distributed nonuniformly without push-pull ventilation; with push-pull ventilation, the control effect increased with decreasing initial diameter. The last case focuses on a ventilation system adapted to local climates. It illustrates that there is an optimal underground tunnel length. In summary, these conclusions offer valuable knowledge to develop high-efficiency ventilation systems with improved indoor air quality and low energy consumption for industrial buildings.

Reducing burden of disease from residential indoor air exposures in Europe (HEALTHVENT project).

BackgroundThe annual burden of disease caused indoor air pollution, including polluted outdoor air used to ventilate indoor spaces, is estimated to correspond to a loss of over 2 million healthy life years in the European Union (EU). Based on measurements of the European Environment Agency (EEA), approximately 90 % of EU citizens live in areas where the World Health Organization (WHO) guidelines for air quality of particulate matter sized < 2.5 mm (PM2.5) are not met. Since sources of pollution reside in both indoor and outdoor air, selecting the most appropriate ventilation strategy is not a simple and straightforward task.MethodsA framework for developing European health-based ventilation guidelines was created in 2010–2013 in the EU-funded HEALTHVENT project. As a part of the project, the potential efficiency of control policies to health effects caused by residential indoor exposures of fine particulate matter (PM2.5), outdoor bioaerosols, volatile organic compounds (VOC), carbon oxide (CO) radon and dampness was estimated. The analysis was based on scenario comparison, using an outdoor-indoor mass-balance model and varying the ventilation rates. Health effects were estimated with burden of diseases (BoD) calculations taking into account asthma, cardiovascular (CV) diseases, acute toxication, respiratory infections, lung cancer and chronic obstructive pulmonary disease (COPD).ResultsThe quantitative comparison of three main policy approaches, (i) optimising ventilation rates only; (ii) filtration of outdoor air; and (iii) indoor source control, showed that all three approaches are able to provide substantial reductions in the health risks, varying from approximately 20 % to 44 %, corresponding to 400 000 and 900 000 saved healthy life years in EU-26. PM2.5 caused majority of the health effects in all included countries, but the importance of the other pollutants varied by country.ConclusionsThe present modelling shows, that combination of controlling the indoor air sources and selecting appropriate ventilation rate was the most effective to reduce health risks. If indoor sources cannot be removed or their emissions cannot be limited to an accepted level, ventilation needs to be increased to remove remaining pollutants. In these cases filtration of outdoor air may be needed to prevent increase of health risks.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-016-0101-8) contains supplementary material, which is available to authorized users.

Roof-integrated PV in Nordic Climate - Building Physical Challenges

Use of photovoltaics (PV) is key remedies in buildings where a large part of the energy supply should be based on renewable energy. PV in Nordic climate can be challenging because ofand temperatures below zero. The aim of this research work has been to provide a state-of-the art overview of recent experiences and challenges for building physical conditions related to the use of roof-integrated PV in Nordic climate. The study has identified practical guidelines for installation and ventilation of the roofing as challenges to be solved for extensive use of such systems in Nordic climate.

Inflammation and the Host Response to Injury, a large-scale collaborative project: Patient-Oriented Research Core--standard operating procedures for clinical care. I. Guidelines for mechanical ventilation of the trauma patient.

Inflammation and the Host Response to Injury, a large-scale collaborative project: Patient-Oriented Research Core--standard operating procedures for clinical care. I. Guidelines for mechanical ventilation of the trauma patient.

PS-385a Clinical Outcomes After Bilevel Positive Airway Pressure (bipap) Treatment For Acute Asthma Exacerbations: Abstract PS-385a Table 1

Aims To examine whether bilevel positive airway pressure (BiPAP) for children with acute asthma exacerbations not approaching respiratory failure (not meeting NIH and GINA guidelines for noninvasive ventilation) is associated with improved clinical outcomes. Methods We prospectively enrolled children 5–17 years with exacerbations not meeting respiratory failure guidelines for BiPAP use in a paediatric emergency department. We modelled propensity scores for BiPAP treatment then used propensity score matching to estimate the associations of BiPAP treatment with hospital admission; PICU admission; hospital length-of-stay; and time to Q4 hr albuterol as a metric of clinical improvement. Results Amongst 933 participants, median [IQR] age was 8.8[6.9,11.2] years, male 61%, and African-American 59%. BiPAP-treated participants (n = 45) had similar demographic characteristics to BiPAP-untreated participants in the matched analysis and significantly greater likelihood of hospital and PICU admission (Table ). Conclusions BiPAP treatment for paediatric patients with asthma exacerbations not meeting respiratory failure guidelines may be associated with greater resource utilisation without evidence of improved outcomes.

Securing adequate indoor air quality (IAQ) across Europe: Developing the health-based ventilation guidelines (HealthVent project)

Background: Inadequate IAQ due to poor ambient air quality and indoor sources of pollution causes a loss of 2 mill. healthy life years annually in EU. Ventilation is one of many factors determining IAQ. Aims: HealthVent project was conducted to form guidelines for health-based ventilation in non-industrial buildings in Europe. Methods. Scientific literature was reviewed to examine association between ventilation and health effects both as regards ventilation rate and the type of ventilation.Risk analysis was performed to examine the impact of different strategies to control exposures and their impact on health in DALYs. Results. The data in the reviewed studies on ventilation and health were found inadequate to set the health–based ventilation rates because the studies improperly characterized exposures and because of the lack of homogeneity. Risk modelling simulations of different strategies resulting in reduction of DALYs suggested that health-based ventilation requirements should be combined with source control strategies and, if necessary, cleaning of outdoor air in order to be efficient. Consequently HealthVent proposed following guidelines. Source control is a key strategy for IAQ. Ventilation should be an ultimate measure to control exposures. WHO air quality guidelines should be used to attest no health risk. When met, the health-based reference minimum ventilation rate is to be set at 4 L/s per person to handle human bioeffluents. When not met after applying source control, ventilation rate should be a multiple of the minimum rate. Air used for ventilation must always meet WHO guidelines. Ventilation system must operate as intended without increasing health risk and must be decoupled from ventilation needed to support thermal comfort. Conclusions: Product labelling, inclusion of IAQ in ambient air quality directives and IAQ audits are among policies needed to implement the guidelines, while population-based measuring campaigns should further support them.

European Guidelines for Ventilation (HealthVent –project): Implications on Energy and Health

European Guidelines for Ventilation (HealthVent –project): Implications on Energy and Health

Proposed ventilation guidelines for Europe (HealthVent-project): Projected changes in sources of exposure and resulting diseases in indoor environment

Proposed ventilation guidelines for Europe (HealthVent-project): Projected changes in sources of exposure and resulting diseases in indoor environment

The Effects of Ventilation in Homes on Health

It is estimated that people in the developed world spend more than 85-90% of their time indoors. Of this, most is spent in homes. To minimize health risks from pollutants occurring in homes, exposures should be controlled. The most effective way to achieve this is to control sources of pollutants and to reduce emissions. Often, especially in existing buildings, this strategy is difficult to implement, in which case exposures are controlled by providing sufficient, presumably clean, outdoor ventilation air to dilute and remove the contaminants.The present paper attempts to find out how much ventilation is needed in existing homes to reduce health risks. This is achieved by reviewing the published scientific literature investigating the association between measured ventilation rates and the measured and observed health problems.The paper concludes that, generally, there are very few studies on this issue and many of them suffer from deficient experimental design, as well as a lack of proper characterization of actual exposures occurring indoors. Based on the available data, in the reviewed studies, it seems likely that health risks may occur when ventilation rates are below 0.4 air changes per hour in existing homes. No data were found indicating that buildings having dedicated natural ventilation systems perform less well than the dwellings in which mechanical ventilation systems are installed. Newly installed mechanical ventilation systems were observed to improve health conditions. In homes with existing ventilation systems this positive effect was less evident, probably due to poor performance of the system (too low ventilation rates and/or poor maintenance).Studies are recommended in which exposures are much better characterized (by for example measuring the pollutants indicated by the WHO Guidelines for Indoor Air Quality and improving ventilation measurements). Exposures should also be controlled using different ventilation methods for comparison. Future studies should also advance the understanding of how ventilation systems should be operated to achieve optimal performance. These data would create further input and support to the guidelines for ventilation based on health developed currently in the framework of the HealthVent project (www.healthvent.eu).

Indoor formaldehyde in real buildings: Emission source identification, overall emission rate estimation, concentration increase and decay patterns

Formaldehyde is a commonly observed indoor air contaminant with proved health effects. For the control of indoor formaldehyde, quick methods applicable in actual buildings are needed to identify the emission sources and estimate overall emission rates. The concentration decay and increase patterns with windows open or closed must also be studied to devise control strategy guidelines for natural ventilation in buildings. In this paper, a quick and easy-to-use method was introduced to identify the emission sources and estimate the overall emission rate resulting from all the emission sources. The method was applied to an apartment unit with multiple formaldehyde sources and showed promising applicability. The formaldehyde concentration decay patterns with different window opening degrees were measured and compared with the concentration increase patterns with closed windows. The results confirmed that natural ventilation through window opening can quickly remove indoor contaminants, and that the time scale of formaldehyde concentration increase is much bigger than that of decay patterns. The results imply that in control of indoor contaminant, natural intermittent ventilation by opening and closing windows is applicable.

Case Study

The National Institute for Occupational Safety and Health (NIOSH) investigators compared methods for collecting personal breathing zone (PBZ) air samples for particulates during abrasive blasting at a shipyard. Abrasive blasting is the cleaning or finishing of surfaces by the use of an abrasive carried in a strong current of air. The U.S. government has provided regulatory requirements and guidelines for ventilation, enclosures, and personal protective equipment during abrasive blasting [NIOSH 1987; OSHA 2012a]. However, current Occupational Safety and Health Administration (OSHA) sampling and analytical methods can overestimate worker exposures to airborne metals and other particulate contaminants during abrasive blasting [NIOSH 1994; NIOSH 1998; OSHA 2012b]. Shielding the 37-mm filter cassette inlet to exclude non-inhalable particles, mounting the PBZ air sampler behind the employee's head to protect the sampler from rebounding abrasive materials, and using the Institute of Medicine inhalable dust sampler, have been proposed as alternatives to assess exposure. All were found to be impractical or ineffective in abrasive blasting environments [NIOSH 1994, 1998]. Sampling simultaneously inside and outside the employees' abrasive blast hood has shown that the lower air concentrations inside the abrasive blast hood produce less overloading of the 37-mm cassettes [NIOSH 1998]; however, sampling inside PPE is not accepted by OSHA for compliance purposes [OSHA 2012a, b]. Aizenberg et al. [2000] used a Button Aerosol Sampler® (BAS) (part number 225–360, SKC Inc., Eighty Four, Pennsylvania) with a prototype shield to evaluate PBZ exposures during abrasive blasting operations. The investigators reported that the protective shield prevented non-inhalable particles from overloading the filter and did not interfere with sampling smaller particles; however, the researchers did not determine whether the prototype protective shield altered the collection efficiency of the BAS. Following the Aizenberg et al. [2000] study, SKC Inc. designed a snap-on dome-shaped stainless steel protective secondary shield for use with the BAS when sampling during abrasive blasting (Abrasive Blasting Sampler for Heavy Metals kit, part number 225–367, SKC Inc., Eighty Four, Pennsylvania). This shield differed in size, shape, and screen opening from the prototype screen tested by Aizenberg et al. [2000]. Due to uncertainty about possible effects that shielding may have on the performance characteristics of the BAS, the objectives of this evaluation were to: (1) compare the commercially available BAS (with and without the shield) with the conventional 37-mm cassette sampler in an abrasive blasting environment and (2) evaluate whether the protective shield designed for the BAS prevented inertia-driven particles from entering and possibly overloading the sampler [NIOSH 2012a].

Novel second-degree solution to single zone mass-balance equation improves the use of build-up data in estimating ventilation rates in classrooms

Recent advances in international guidelines for indoor air quality and on-going work on guidelines for ventilation in Europe increase the need for routinely applicable measurement methods for indoor air quality and ventilation. Ventilation is the key determinant of the behaviour of pollution from both indoors and outdoors in buildings and therefore should be measured together with other indicators of indoor air quality. Various methods have been proposed to measure ventilation rates in different types of buildings. Utilizing carbon dioxide as a marker substance and applying several ventilation phase-based methods together allows for recognizing air recirculation and quantifying CO 2 emission levels that have been identified as challenges in CO 2 -based methods, as well estimating the intrinsic variability of ventilation rates over various levels of occupancy. In schools CO 2 based estimation of ventilation has often been applied to decay phase only, which is not representative of exposure of the school children while using time periods when the classroom is not occupied and when the ventilation may be enhanced, e.g., by opening windows. This paper presents a novel solution to the mass-balance equation facilitating the use of the build-up phase to solve air exchange rates. The new equation allows to avoid impacts of device calibration errors and in combination with previously used steady state and decay methods improves significantly representativity of ventilation estimates in schools. Practical implications Combined use of occupancy phase based ventilation assessment method improves the quality of CO 2 -based estimates of ventilation alone and as part of more comprehensive indoor environmental quality measurements.

993 Implementation of Ventilation Policy in a Picu

Background and AimsPediatric intensive care units (PICU) worldwide use different ventilators with a wide variety of ventilation modes. As an unambiguous international ventilation guideline, we developed one. After implementation we...

고속도로 터널의 적정 환기용량 계획을 위한 원활 및 지체조건 판별모델 개발에 대한 연구

According to the local highway tunnel ventilation guideline, ventilation capacity calculation should be performed at the speed ranging from 10 km/h to 80 km/h. This is so reasonable method considering uncongested and congested traffic conditions in urban tunnels. But recently due to low traffic volume and very low congestion frequency in rural highway tunnels, it seems to be an inadequate way to apply the guideline. Therefore the calculation should be performed separately for the free flow and congested traffic cases classified by the appropriate decision model. This paper aims at determining unnecessary running speed range for reasonable tunnel ventilation design, considering free flow and congested traffic conditions. Firstly, traffic volumes in highway tunnels were collected and if any, the causes of congestion were investigated. And with concept of 'margin speed'(u  u m ), the decision model on traffic congestion was developed. Applicability of the decision model was also analyzed with case study. According to the results, when design speed is 100 km/h, with V/C less than 0.1, then the range of unnecessary speed in tunnel ventilation design is less than 40 km/h; for V/C ≦ 0.35, V/C ≦ 0.6 and V/C ≦ 0.75, the unnecessary speed ranges are found to be ≦ 30, ≦ 20 and ≦ 10 km/h, respectively.

Exposure Assessment in Nail Salons: An Indoor Air Approach

Due to the complexity of the nail salon work environment, traditional approaches to exposure assessment in this context tend to mischaracterize potential hazards as nuisances. For this investigation, a workable “indoor air” approach was devised to characterize potential hazards and ventilation in Boston, Massachusetts area nail salons which are primarily owned and staffed by Vietnamese immigrants. A community-university partnership project recruited salons to participate in a short audit which included carbon dioxide measurements and evaluation of other air quality metrics. Twenty-two salons participated. Seventy-three percent of the salons had spot carbon dioxide measurements in excess of 700 ppm, the level corresponding to a ventilation rate recommended for beauty salons. Fourteen salons (64%) did not have a mechanical ventilation system to provide fresh air and/or exhaust contaminated air. The lack of adequate ventilation is of significant concern because of the presence of potentially hazardous chemicals in salon products and the common self-report of symptoms among nail technicians. Community and worker health may be improved through adoption of recommended ventilation guidelines and reduction in the hazard potential of nail products.

Deviations from evidence-based clinical management guidelines increase mortality in critically injured trauma patients*

The effect of treatment guidelines on clinical outcomes in general and specifically for trauma patients has not been well-studied. We hypothesized that better compliance with guidelines would be associated with improved clinical outcomes. Prospective, randomized, double-blinded, multicentered, placebo-controlled study of recombinant factor VII in severe trauma that utilized guidelines for damage control, transfusions, and mechanical ventilation. Vanderbilt Coordinating Center reviewed compliance in near real-time and reported deviations classified as minor, moderate, or major to investigators. Multivariate regression analysis measured the association between outcomes (30-day and 90-day mortality, development of multiple organ failure, ventilator-free days, renal failure-free days, and blood products transfused) and compliance with each guideline, as well as a composite assessment of overall compliance. One hundred hospitals in 26 countries. Blunt and/or penetrating trauma patients aged 18-70 yrs who had received 4-8 units of red blood cells for active torso and/or proximal lower extremity bleeding despite standard interventions. When assessed as composite end point, major deviations from guidelines were associated with significantly higher mortality at 30 and 90 days after injury and fewer renal failure-free days. Moderate deviations were associated with a significantly higher risk of multiple organ failure and fewer ventilator-free days. Moderate and major deviations from damage control and ventilation guidelines were also significantly associated with higher risk of death at days 30 and 90. Within the ventilation protocol, noncompliance with tidal volume and plateau pressure targets was associated with significantly higher mortality at days 30 and 90 and fewer ventilator-free days, whereas noncompliance with weaning guideline was only associated with significantly fewer ventilator-free days. : In a clinical trial of trauma patients, higher compliance with guidelines for damage control, transfusion, and ventilation management is associated with lower mortality and improved outcomes.

Exposure and cancer risk toward cooking-generated ultrafine and coarse particles in Hong Kong homes

Particulate matters generated during cooking contain various carcinogens. These particles consist of both ultrafine particles (nanoparticle) and coarse particles. Exposure and risk-assessment studies often use particle mass concentration as dosimetry, which ignores the impact of ultrafine particles due to their insignificant mass compared to coarse particles. This study aims at characterizing the cancer risk toward cooking-generated particulate matter using Hong Kong homes as an example. A risk-assessment scheme modified from an existing risk model was developed to consider the cancer risk contributed from both fine ultrafine and coarse particles. Exposure assessment was conducted based on particle concentration data measured in 16 Hong Kong homes. The predicted cancer risk was then compared to the cancer incidence rate in Hong Kong to examine its appropriateness. It was found that the ultrafine particles contribute a much higher risk than that of coarse particles, and the modified risk-assessment scheme gives an estimate much closer to the incidence rate than the conventional scheme. Use of grease extractor cannot completely contain the particles, and a significant portion of particles can be transported from kitchens to other regions of the homes. The modified risk assessment scheme can serve as a tool in assessing environmental quality as well as setting up design and ventilation guidelines and exposure standards on particulate matters.