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https://www.readbyqxmd.com/read/29335661/weather-correlations-to-calculate-infiltration-rates-for-u-s-commercial-building-energy-models
#1
Lisa C Ng, Nelson Ojeda Quiles, W Stuart Dols, Steven J Emmerich
As building envelope performance improves, a greater percentage of building energy loss will occur through envelope leakage. Although the energy impacts of infiltration on building energy use can be significant, current energy simulation software have limited ability to accurately account for envelope infiltration and the impacts of improved airtightness. This paper extends previous work by the National Institute of Standards and Technology that developed a set of EnergyPlus inputs for modeling infiltration in several commercial reference buildings using Chicago weather...
January 2018: Building and Environment
https://www.readbyqxmd.com/read/29298386/diversity-of-dna-and-rna-viruses-in-indoor-air-as-assessed-via-metagenomic-sequencing
#2
Karyna Rosario, Noah Fierer, Shelly Lynn Miller, Julia Luongo, Mya Breitbart
Diverse bacterial and fungal communities inhabit human-occupied buildings and circulate in indoor air; however, viral diversity in these man-made environments remains largely unknown. Here we investigated DNA and RNA viruses circulating in the air of twelve university dormitory rooms by analyzing dust accumulated over a one-year period on heating, ventilation, and air conditioning (HVAC) filters. A high-throughput metagenomic sequencing approach was used to determine the identity and diversity of viral particles extracted from the HVAC filters...
January 3, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29280511/modeling-the-resiliency-of-energy-efficient-retrofits-in-low-income-multifamily-housing
#3
Lindsay Jeanne Underhill, Maria Patricia Fabian, Kimberly Vermeer, Megan Sandel, Gary Adamkiewicz, Jessica H Leibler, Jonathan Ian Levy
Residential energy efficiency and ventilation retrofits (e.g., building weatherization, local exhaust ventilation, HVAC filtration) can influence indoor air quality (IAQ) and occupant health, but these measures' impact varies by occupant activity. In this study, we used the multi-zone airflow and IAQ analysis program CONTAM to simulate the impacts of energy retrofits on indoor concentrations of PM2.5 and NO2 in a low-income multifamily housing complex in Boston, Massachusetts (USA). We evaluated the differential impact of residential activities, such as low- and high-emission cooking, cigarette smoking, and window-opening, on IAQ across two seasons...
December 27, 2017: Indoor Air
https://www.readbyqxmd.com/read/29167584/performance-monitoring-of-chilled-water-distribution-systems-using-hvac-cx
#4
Natascha Milesi Ferretti, Michael A Galler, Steven T Bushby
In this research we develop, test, and demonstrate the newest extension of the software HVAC-Cx (NIST and CSTB 2014), an automated commissioning tool for detecting common mechanical faults and control errors in chilled-water distribution systems (loops). The commissioning process can improve occupant comfort, ensure the persistence of correct system operation, and reduce energy consumption. Automated tools support the process by decreasing the time and the skill level required to carry out necessary quality assurance measures, and as a result they enable more thorough testing of building heating, ventilating, and air-conditioning (HVAC) systems...
2017: ASHRAE Transactions
https://www.readbyqxmd.com/read/29107263/clinical-issues-november-2017
#5
Esther M Johnstone
Heating, ventilation, and air-conditioning (HVAC) systems in the OR Key words: airborne contaminants, HVAC system, air pressure, air quality, temperature and humidity. Air changes and positive pressure Key words: air changes, positive pressure airflow, unidirectional airflow, outdoor air, recirculated air. Product selection Key word: product evaluation, product selection, selection committee. Entry into practice Key words: associate degree in nursing, bachelor of science in nursing, entry-level position, advanced education, BSN-prepared RNs...
November 2017: AORN Journal
https://www.readbyqxmd.com/read/29104349/ten-questions-concerning-the-aerosolization-and-transmission-of-legionella-in-the-built-environment
#6
Aaron J Prussin, David Otto Schwake, Linsey C Marr
Legionella is a genus of pathogenic Gram-negative bacteria responsible for a serious disease known as legionellosis, which is transmitted via inhalation of this pathogen in aerosol form. There are two forms of legionellosis: Legionnaires' disease, which causes pneumonia-like symptoms, and Pontiac fever, which causes influenza-like symptoms. Legionella can be aerosolized from various water sources in the built environment including showers, faucets, hot tubs/swimming pools, cooling towers, and fountains. Incidence of the disease is higher in the summertime, possibly because of increased use of cooling towers for air conditioning systems and differences in water chemistry when outdoor temperatures are higher...
October 2017: Building and Environment
https://www.readbyqxmd.com/read/29074027/an-innovative-hvac-control-system-implementation-and-testing-in-a-vehicular-cabin
#7
Miloš Fojtlín, Jan Fišer, Jan Pokorný, Aleš Povalač, Tomáš Urbanec, Miroslav Jícha
Personal vehicles undergo rapid development in every imaginable way. However, a concept of managing a cabin thermal environment remains unchanged for decades. The only major improvement has been an automatic HVAC controller with one user's input - temperature. In this case, the temperature is often deceiving because of thermally asymmetric and dynamic nature of the cabins. As a result, the effects of convection and radiation on passengers are not captured in detail what also reduces the potential to meet thermal comfort expectations...
December 2017: Journal of Thermal Biology
https://www.readbyqxmd.com/read/29060816/assessment-of-auditory-impression-of-the-coolness-and-warmness-of-automotive-hvac-noise
#8
Seiji Nakagawa, Takuya Hotehama, Masaru Kamiya
Noise induced by a heating, ventilation and air conditioning (HVAC) system in a vehicle is an important factor that affects the comfort of the interior of a car cabin. Much effort has been devoted to reduce noise levels, however, there is a need for a new sound design that addresses the noise problem from a different point of view. In this study, focusing on the auditory impression of automotive HVAC noise concerning coolness and warmness, psychoacoustical listening tests were performed using a paired comparison technique under various conditions of room temperature...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28829721/assessment-of-indoor-levels-of-volatile-organic-compounds-and-carbon-dioxide-in-schools-in-kuwait
#9
Layla Al-Awadi
Indoor air quality (IAQ) in schools is a matter of concern because children are most vulnerable and sensitive to pollutant exposure. Conservation of energy at the expense of ventilation in heating, ventilation, and air conditioning (HVAC) systems adversely affects IAQ. Extensive use of new materials in building, fitting, and refurbishing emit various pollutants such that the indoor environment creates its own discomfort and health risks. Various schools in Kuwait were selected to assess their IAQ. Comprehensive measurements of volatile organic compounds (VOCs) consisting of 72 organic compounds consisting of aliphatic (C3-C6), aromatic (C6-C9), halogenated (C1-C6), and oxygenated (C2-C9) functional groups in indoor air were made for the first time in schools in Kuwait...
August 22, 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/28781568/simultaneously-reducing-co2-and-particulate-exposures-via-fractional-recirculation-of-vehicle-cabin-air
#10
Heejung S Jung, Michael L Grady, Tristan Victoroff, Arthur L Miller
Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle...
July 2017: Atmospheric Environment
https://www.readbyqxmd.com/read/28683161/the-ventilation-problem-in-schools-literature-review
#11
REVIEW
W J Fisk
Based on a review of literature published in refereed archival journals, ventilation rates in classrooms often fall far short of the minimum ventilation rates specified in standards. There is compelling evidence, from both cross-sectional and intervention studies, of an association of increased student performance with increased ventilation rates. There is evidence that reduced respiratory health effects and reduced student absence are associated with increased ventilation rates. Increasing ventilation rates in schools imposes energy costs and can increase heating, ventilating, and air-conditioning system capital costs...
November 2017: Indoor Air
https://www.readbyqxmd.com/read/28370427/ventilation-rates-in-recently-constructed-u-s-school-classrooms
#12
S Batterman, F-C Su, A Wald, F Watkins, C Godwin, G Thun
Low ventilation rates (VRs) in schools have been associated with absenteeism, poorer academic performance, and teacher dissatisfaction. We measured VRs in 37 recently constructed or renovated and mechanically ventilated U.S. schools, including LEED and EnergyStar-certified buildings, using CO2 and the steady-state, build-up, decay, and transient mass balance methods. The transient mass balance method better matched conditions (specifically, changes in occupancy) and minimized biases seen in the other methods...
September 2017: Indoor Air
https://www.readbyqxmd.com/read/28256293/use-of-a-home-vacuum-assisted-closure-device-in-the-burn-population-is-both-cost-effective-and-efficacious
#13
Oren P Mushin, Jarrod T Bogue, Mica D Esquenazi, Nicole Toscano, Derek E Bell
INTRODUCTION: The vacuum assisted closure device (VAC) improves wound-healing when utilized as a bolster to secure split thickness skin grafts (STSG). Patients typically remain hospitalized for VAC therapy; however, home VACs (hVAC) are now available. Limited studies examine burns treated with hVAC as a STSG bolster. METHOD: A retrospective study of records from an ABA verified regional burn center was conducted over 23 months. Patients included STSGs for burn. Data points included demographics, burn mechanism and location, graft characteristics, hospital length of stay (LOS), and time to heal...
May 2017: Burns: Journal of the International Society for Burn Injuries
https://www.readbyqxmd.com/read/28242974/unit-cost-analysis-of-pet-ct-at-an-apex-public-sector-health-care-institute-in-india
#14
S H Gajuryal, A Daga, V Siddharth, C S Bal, S Satpathy
CONTEXT: PET/CT scan service is one of the capital intensive and revenue-generating centres of a tertiary care hospital. The cost associated with the provisioning of PET services is dependent upon the unit costs of the resources consumed. AIMS: The study aims to determine the cost of providing PET/CT Scan services in a hospital. METHODS AND MATERIAL: This descriptive and observational study was conducted in the Department of Nuclear Medicine at a tertiary apex teaching hospital in New Delhi, India in the year 2014-15...
January 2017: Indian Journal of Nuclear Medicine: IJNM: the Official Journal of the Society of Nuclear Medicine, India
https://www.readbyqxmd.com/read/28165398/review-and-extension-of-co%C3%A2-based-methods-to-determine-ventilation-rates-with-application-to-school-classrooms
#15
Stuart Batterman
The ventilation rate (VR) is a key parameter affecting indoor environmental quality (IEQ) and the energy consumption of buildings. This paper reviews the use of CO₂ as a "natural" tracer gas for estimating VRs, focusing on applications in school classrooms. It provides details and guidance for the steady-state, build-up, decay and transient mass balance methods. An extension to the build-up method and an analysis of the post-exercise recovery period that can increase CO₂ generation rates are presented. Measurements in four mechanically-ventilated school buildings demonstrate the methods and highlight issues affecting their applicability...
February 4, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28134841/ultrafine-and-fine-particulate-matter-inside-and-outside-of-mechanically-ventilated-buildings
#16
Shelly L Miller, Nick A Facciola, Darin Toohey, John Zhai
The objectives of this study were to measure levels of particulate matter (PM) in mechanically ventilated buildings and to improve understanding of filtration requirements to reduce exposure. With the use of an Ultra High Sensitivity Aerosol Spectrometer and an Aerodyne Mass Spectrometer, ultrafine (0.055-0.1 μm) and fine (0.1-0.7 μm) indoor and outdoor PM was measured as a function of time in an office, a university building, and two elementary schools. Indoor particle levels were highly correlated with outdoor levels...
January 28, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28124067/vocal-ergonomics-in-the-workplace-heating-ventilation-and-air-conditioning-method-influences-on-vocal-comfort-and-function
#17
Mary J Sandage, Keith A Rahn, Audrey G Smith
Purpose: The purpose of this study was to examine the influence of the heating, ventilation, and air-conditioning method on voice function following a voicing task using ecologically valid offices, one with radiant HVAC and one with forced air. Method: A total of 12 consented participants (6 women, 6 men) narrated a video in each of 4 environmental conditions in a within-between repeated-measures design. Acoustic data were collected with an ambulatory phonation monitor and perceived phonatory effort was determined following the voicing task...
February 1, 2017: Journal of Speech, Language, and Hearing Research: JSLHR
https://www.readbyqxmd.com/read/28079171/comfortable-high-efficiency-heat-pump-with-desiccant-coated-water-sorbing-heat-exchangers
#18
Y D Tu, R Z Wang, T S Ge, X Zheng
Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8-3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed...
January 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/27960651/in-vehicle-carbon-dioxide-concentration-in-commuting-cars-in-bangkok-thailand
#19
Maytat Luangprasert, Chainarin Vasithamrong, Suphasit Pongratananukul, Sunhapos Chantranuwathana, Suree Pumrin, I P D De Silva
It is known that in-vehicle carbon dioxide (CO2) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO2 concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied...
May 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/27924457/comparison-of-methods-to-evaluate-the-fungal-biomass-in-heating-ventilation-and-air-conditioning-hvac-dust
#20
Marie-Jeanne Biyeyeme Bi Mve, Yves Cloutier, Nancy Lacombe, Jacques Lavoie, Maximilien Debia, Geneviève Marchand
Heating, ventilation, and air-conditioning (HVAC) systems contain dust that can be contaminated with fungal spores (molds), which may have harmful effects on the respiratory health of the occupants of a building. HVAC cleaning is often based on visual inspection of the quantity of dust, without taking the mold content into account. The purpose of this study is to propose a method to estimate fungal contamination of dust in HVAC systems. Comparisons of different analytical methods were carried out on dust deposited in a controlled-atmosphere exposure chamber...
December 2016: Environmental Monitoring and Assessment
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