Ambiência - Controle de climatização de ambientes em BLH e Postos de Coleta de Leite Humano / Ambientación - Climatización de ambientes en Bancos de Leche Humana y Centros de Recolección de Leche Humana / Ambience - Climate control of environments in HMB and Human Milk Collection Stations

Esta Norma Técnica tem por objetivo estabelecer as medidas para monitorar, adequar, e assegurar os padrões de qualidade do ar em ambientes climatizados em Bancos de Leite Humano e Postos de Coleta de Leite Humano, visando a garantia da qualidade nestes serviços e sua certificação.

Esta Norma Técnica tiene por objetivo establecer las medidas para monitorear, ajustar y asegurar los estándares de calidad del aire en los ambientes climatizados de los Bancos de Leche Humana y Centros de Recolección de Leche Humana, con el fin de asegurar la calidad de estos servicios y su certificación.

Physiological and subjective comfort evaluation under different airflow directions in a cooling environment.

Indoor comfort is influenced by airflow direction, but subjective evaluations can differ. This study evaluates the airflow comfort with subjective assessments and physiological measurements, including skin temperature, electroencephalograms, and electrocardiograms. Nineteen participants entered a test room at 20°C after staying in a room at 32°C for acclimation. They were exposed to indirect and direct airflow conditions to their faces and performed four tasks under each condition: resting, counting to 10 s following time alerts, counting to 10 s in mind, and mental calculation. Subjective assessments showed relatively higher thermal sensation and pleasantness under indirect airflow. The psychological time calculated from counting behaviors was longer under indirect airflow, indicating suppression of negative emotions. The face temperatures significantly declined during experiments under direct airflow. The beta and gamma bands of electroencephalograms were inhibited under the indirect condition, and these amplitudes were negatively correlated with pleasant feelings. Electrocardiogram parameters indicated that sympathetic nervous activity was predominant during counting, following alerts and mental calculation in indirect airflow. This study supports the comfort of indirect airflow based on reliable evidence.

Recomendaciones para calefacción, ventilación y aire acondicionado en establecimientos de salud, octubre del 2020 / Recommendations for Heating, Ventilation, and Air Conditioning in Healthcare Facilities, October 2020

Proporcionar condiciones térmicas y sistemas de ventilación adecuados que eviten la dispersión de patógenos es fundamental para proteger la salud de los pacientes, de los profesionales médicos y de enfermería, y del resto del personal, así como para el funcionamiento general de los equipos sensibles. Esta segunda versión presenta recomendaciones generales para evitar la transmisión del SARS-CoV-2 a través de sistemas de calefacción, ventilación y aire acondicionado en establecimientos de salud.

Providing adequate thermal conditions and ventilation systems that prevent the dispersion of pathogens, is fundamental to protect the health of patients, caregivers and staff, and to the overall operation of sensitive equipment. This technical note presents general recommendations to prevent the transmission of SARS-CoV-2 through heating, ventilation, and air conditioning systems in ​health care facilities.

Assessment and mitigation of aerosol airborne SARS-CoV-2 transmission in laboratory and office environments.

Bioaerosols are known to be an important transmission pathway for SARS-CoV-2. We report a framework for estimating the risk of transmitting SARS-CoV-2 via aerosols in laboratory and office settings, based on an exponential dose-response model and analysis of air flow and purification in typical heating, ventilation, and air conditioning (HVAC) systems. High-circulation HVAC systems with high-efficiency particulate air (HEPA) filtration dramatically reduce exposure to the virus in indoor settings, and surgical masks or N95 respirators further reduce exposure. As an example of our risk assessment model, we consider the precautions needed for a typical experimental physical science group to maintain a low risk of transmission over six months of operation. We recommend that, for environments where fewer than five individuals significantly overlap, work spaces should remain vacant for between one (high-circulation HVAC with HEPA filtration) to six (low-circulation HVAC with no filtration) air exchange times before a new worker enters in order to maintain no more than 1% chance of infection over six months of operation in the workplace. Our model is readily applied to similar settings that are not explicitly given here. We also provide a framework for evaluating infection mitigation through ventilation in multiple occupancy spaces.

Use of a Support Surface Standard to Test the Effects of a Turning and Positioning Device Versus Low-Air-Loss Therapy on Temperature and Humidity.

BACKGROUND: Turning and repositioning devices (TRDs) help to reduce strain on caregivers, but clinicians question their effects on humidity and temperature (microclimate) at the skin surface that may increase risk of pressure ulcers. OBJECTIVE: To pilot the use of a standard test for support surfaces to compare microclimate at the skin surface in three scenarios: (1) on a low-air-loss (LAL) surface, (2) on a representative TRD with a basic underpad (TRDU) placed on a LAL surface, and (3) on a negative control with full occlusion. The results are designed to inform clinical decision-making in using a TRD on a LAL surface and the viability of using this test to study TRDs. DESIGN: Measuring humidity and temperature at the device-surface interface using a heated moisture-exuding bronze thermodynamic human model in a laboratory setting. MAIN OUTCOME MEASURE: Humidity and temperature levels across 3 hours 15 minutes of continuous loading with a 45-second complete unloading to simulate a position change at 3 hours. MAIN RESULTS: Relative humidity on the TRDU was below that on the LAL surface for the first 110 minutes and was markedly lower than the negative control for the remainder of humidity testing. Temperature on the TRDU was well below the negative control and negligibly higher than the surface alone throughout testing. The position change enhanced the effects of the TRDU. CONCLUSIONS: The support surface standard test appears useful in evaluating TRDs. This TRD along with the basic underpad is more comparable to a LAL surface than to full occlusion in managing the microclimate of the skin and pressure ulcer risk.

Back to Normal: An Old Physics Route to Reduce SARS-CoV-2 Transmission in Indoor Spaces.

We advocate the widespread use of UV-C light as a short-term, easily deployable, and affordable way to limit virus spread in the current SARS-CoV-2 pandemic. Radical social distancing with the associated shutdown of schools, restaurants, sport clubs, workplaces, and traveling has been shown to be effective in reducing virus spread, but its economic and social costs are unsustainable in the medium term. Simple measures like frequent handwashing, facial masks, and other physical barriers are being commonly adopted to prevent virus transmission. However, their efficacy may be limited, particularly in shared indoor spaces, where, in addition to airborne transmission, elements with small surface areas such as elevator buttons, door handles, and handrails are frequently used and can also mediate transmission. We argue that additional measures are necessary to reduce virus transmission when people resume attending schools and jobs that require proximity or some degree of physical contact. Among the available alternatives, UV-C light satisfies the requirements of rapid, widespread, and economically viable deployment. Its implementation is only limited by current production capacities, an increase of which requires swift intervention by industry and authorities.

Recomendaciones para calefacción, ventilación y aire acondicionado en establecimientos de salud, 21 de mayo del 2020 / Recommendations for Heating, Ventilation, and Air Conditioning in Health Care Facilities, 21 May 2020

Esta ficha técnica presenta recomendaciones generales para evitar la transmisión del SARS-CoV-2 por medio de sistemas de calefacción, ventilación y aire acondicionado en establecimientos de salud.

This technical note presents general recommendations to prevent the transmission of SARS-CoV-2 through heating, ventilation, and air conditioning systems in ​health care facilities.

Indoor Air Quality in the Hospital: The Influence of Heating, Ventilating and Conditioning Systems

Abstract Clean, fresh air is the most important requirement for good indoor air quality (IAQ) in all buildings, but it is especially important with regard to the environments within hospitals and other healthcare facilities. The literature indicates that buildings with heating, ventilating and air conditioning (HVAC) systems may have an increased risk of sick building syndrome (SBS) and building-related illness (BRI) if they are not well maintained. Microorganisms are brought into hospitals by people, air currents, water, construction materials and equipment. The main objective of this study was to assess the degree of fungal and bacterial contamination in the University Clinical Centre in Banja Luka, which is directly connected to the HVAC system. Airborne bacteria and fungi in the indoor hospital environment were assessed experimentally. Air samples were collected during the winter season. This paper presents the results related to the concentration of microorganisms expressed in colony forming units per cubic metre of air sampled (in CFU/m3) together with the microclimatic parameters temperature and relative humidity. The results of monitoring indicate the effectiveness of HVAC systems in reducing microbiological contamination.

Heating, ventilation and air conditioning (HVAC) system, microbial air contamination and surgical site infection in hip and knee arthroplasties: the GISIO-SItI Ischia study.

BACKGROUND: Recent studies have questioned the role of unidirectional airflow ventilation system in reducing surgical site infection (SSI) in prosthetic implant surgery. The aim of the ISChIA study ("Infezioni del Sito Chirurgico in Interventi di Artroprotesi" which means "Surgical site infections in arthroplasty surgery") was to evaluate, as a contribution to this debate, the association between heating, ventilation and air conditioning systems, microbial air contamination and surgical site infection in hip and knee arthroplasty. METHODS: The study was performed from March 2010 to February 2012 in 14 hospitals, for a total of 28 operating theatres: 16 were equipped with vertical unidirectional airflow ventilation (U-OTs), 6 with mixed airflow ventilation (M-OTs), 6 with turbulent airflow ventilation (T-OTs). Microbial air contamination in the operating theatre was evaluated by means of passive (Index of Microbial Air contamination, IMA) and active (Colony Forming Units per cubic metre, cfu/m3) sampling. SSI surveillance was carried out according to the Hospitals in Europe Link for Infection Control through Surveillance protocol. RESULTS: A total of 1,285 elective prosthesis procedures (61.1% hip and 38.9% knee) were included in the study. The results showed a wide variability of the air microbial contamination in operating theatres equipped with unidirectional airflow. The recommended values of ≤2 IMA and ≤10 cfu/m3 were exceeded, respectively, by 58.9% and 46.4% of samples from U-OTs and by 87.6% and 100% of samples from M-OTs. No significant difference was observed between SSI cumulative incidence in surgical procedures performed in U-OTs compared with those performed in T-OTs. A lower risk of SSI, even though not statistically significant, was shown in surgical procedures performed in U-OTs with a microbial air contamination within the recommended values (≤2 IMA and ≤10 cfu/m3) compared with those performed in U-OTs where these limits were exceeded, and compared with those performed in T-OTs with microbial air contamination within the recommended values for this type of OTs (≤25 IMA, ≤180 cfu/m3. CONCLUSION: ISChIA study did not show a protective effect of unidirectional airflow compared with turbulent airflow in arthroplasty surgery. However, the frequent exceeding of recommended air microbial contamination values in OTs equipped with unidirectional airflow, and the lower SSI risk in surgical procedures performed in compliant U-OTs compared with those performed in non-compliant U-OTs and with those performed in compliant T-OTs, suggest the need of further studies, which should consider air microbial contamination and other aspects of SSI prevention that may negate the potential benefits of the ventilation system; differences in intrinsic and extrinsic risk factors, medical treatment and surgical technique are also to be considered. Training interventions aimed at improving the behaviour of operators are essential.

Association between Four-Level Categorisation of Indoor Exposure and Perceived Indoor Air Quality.

The aim of this study was to develop and test a tool for assessing urgency of indoor air quality (IAQ) measures. The condition of the 27 buildings were investigated and results were categorized. Statistical test studied the differences between the categories and the employees’ complaints about their work environment. To study the employees’ experiences of the work premises, a validated indoor air (IA) questionnaire was used. This study reveals a multifaceted problem: many factors affecting IAQ may also affect perceived IAQ, making it difficult to separate the impurity sources and ventilation system deficiencies affecting to employee experiences. An examination of the relationship between the categories and perceived IAQ revealed an association between the mould odour perceived by employees and mould detected by the researcher. A weak link was also found between the assessed categories and environmental complaints. However, we cannot make far-reaching conclusions regarding the assessed probability of abnormal IA exposure in the building on the basis of employee experiences. According to the results, categorising tool can partly support the assessment of the urgency for repairs when several factors that affect IAQ are taken into account.

Does the air condition system in busses spread allergic fungi into driver space?

The aim of this study was to establish whether the air-conditioning system in buses constitutes an additional source of indoor air contamination with fungi, and whether or not the fungi concentration depends on the period from the last disinfection of the system, combined with replacement of the cabin dust particle filter. The air samples to fungi analysis using impact method were taken in 30 buses (20 with an air-conditioning system, ACS; 10 with a ventilation system, VS) in two series: 1 and 22 weeks after cabin filter replacement and disinfection of the air-conditioning system. During one test in each bus were taken two samples: before the air-conditioning or ventilation system switched on and 6 min after operating of these systems. The atmospheric air was the external background (EB). After 1 week of use of the system, the fungi concentrations before starting of the ACS and VS system were 527.8 and 1053.0 cfu/m3, respectively, and after 22 weeks the concentrations were 351.9 and 1069.6 cfu/m3, respectively. While in the sample after 6 min of ACS and VS system operating, the fungi concentration after 1 week of use was 127.6 and 233.7 cfu/m3, respectively, and after 22 weeks it was 113.3 and 324.9 cfu/m3, respectively. Results do not provide strong evidence that air-conditioning system is an additional source of indoor air contamination with fungi. A longer operation of the system promoted increase of fungi concentration in air-conditioned buses only.

Comfort, Energy Efficiency and Adoption of Personal Cooling Systems in Warm Environments: A Field Experimental Study.

It is well known that personal cooling improves thermal comfort and save energy. This study aims to: (1) compare different personal cooling systems and (2) understand what influences users' willingness to adopt them. A series of experiments on several types of personal cooling systems, which included physical measurements, questionnaires and feedback, was conducted in a real office environment. The obtained results showed that personal cooling improved comfort of participants in warm environments. Then an improved index was proposed and used to compare different types of personal cooling systems in terms of comfort and energy efficiency simultaneously. According to the improved index, desk fans were highly energy-efficient, while the hybrid personal cooling (the combination of radiant cooling desk and desk fan) consumed more energy but showed advantages of extending the comfortable temperature range. Moreover, if personal cooling was free, most participants were willing to adopt it and the effectiveness was the main factor influencing their willingness, whereas if participants had to pay, they probably refused to adopt it due to the cost and the availability of conventional air conditioners. Thus, providing effective and free personal cooling systems should be regarded as a better way for its wider application.

An innovative HVAC control system: Implementation and testing in a vehicular cabin.

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. Advanced methodologies are available to assess the cabin environment in a fine resolution (e.g. ISO 14505:2006), but these are used mostly in laboratory conditions. The novel idea of this work is to integrate equivalent temperature sensors into a vehicular cabin in proximity of an occupant. Spatial distribution of the sensors is expected to provide detailed information about the local environment that can be used for personalised, comfort driven HVAC control. The focus of the work is to compare results given by the implemented system and a Newton type thermal manikin. Three different ambient settings were examined in a climate chamber. Finally, the results were compared and a good match of equivalent temperatures was found.

Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China.

Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments' conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm) and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC) located in the hot summer and cold winter (HSCW) climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET*) was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

Ozone generated by air purifier in low concentrations: friend or foe?

Ozone helps decontamination environments due to its oxidative power, however present toxicity when it is in high concentrations, by long periods of exposition. This study aimed to assess the safety of ozone generator air purifier at concentrations of 0.05 ppm in rats exposed to 3 and 24 h/day for 14 and 28 days. No significant differences are observed between groups in clinical signs, feed and water intake, relative body weight gain and relative weight of organs, macroscopy and microscopy of lungs, and oxidative plasma assay. In this exposure regime, ozone does not cause genotoxicity and no significant changes in pulmonary histology indicative of toxicity. Ozone generated in low concentrations, even in exposure regimes above the recommended is safe, both acute and sub-acute exposition.

Modeling and Qualification of a Modified Emission Unit for Radioactive Air Emissions Stack Sampling Compliance.

A planned laboratory space and exhaust system modification to the Pacific Northwest National Laboratory Material Science and Technology Building indicated that a new evaluation of the mixing at the air sampling system location would be required for compliance to ANSI/HPS N13.1-2011. The modified exhaust system would add a third fan, thereby increasing the overall exhaust rate out the stack, thus voiding the previous mixing study. Prior to modifying the radioactive air emissions exhaust system, a three-dimensional computational fluid dynamics computer model was used to evaluate the mixing at the sampling system location. Modeling of the original three-fan system indicated that not all mixing criteria could be met. A second modeling effort was conducted with the addition of an air blender downstream of the confluence of the three fans, which then showed satisfactory mixing results. The final installation included an air blender, and the exhaust system underwent full-scale tests to verify velocity, cyclonic flow, gas, and particulate uniformity. The modeling results and those of the full-scale tests show agreement between each of the evaluated criteria. The use of a computational fluid dynamics code was an effective aid in the design process and allowed the sampling system to remain in its original location while still meeting the requirements for sampling at a well mixed location.

[ESTIMATION OF THE EFFICIENCY OF THE TREATMENT OF SPLIT-SYSTEMS IN RESIDENTIAL AREAS IN ORDER TO REDUCE THE LEVEL OF THE PREVALENCE OF DISEASES OF THE RESPIRATORY SYSTEM].

UNLABELLED: The purpose of work: comparison of prevalence among residents, which use or fail to use to clean split systems. MATERIALS AND METHODS: Collected information about morbidity rate in 235 cases people during 3 years. RESULTS: The usage of split-systems without their regular cleaning leads to the gain in the level of the prevalence of respiratory diseases by 172.7% if compared with persons, who have no air conditioning systems at home. Also, the average number of disability days increases by 218.1%) and average time of the duration of the disease increases by 71.9%. The annual treatment of split-systems and regular cleaning of filters allowed to reduce the number of diseases. In comparison with the group of people, who fail to clean air conditioning systems, the drop of morbidity rate by 56.6%, average number of disability days by 63.3% and average time of diseases by 30.9% was observed. Regular treatment of air conditioning systems cannot completely repay the morbidity rates to the level of the control group. In comparison with the people, who use no air conditioning systems, the owners of split-systems with regular treatment have lung diseases by 18.4% more often. The average number of disability days and the average time of diseases increased by 16.9% and 18.8%. These changes can be explained by the impact of unfavorable (cooling) microclimate. CONCLUSIONS: The impact of split-systems on the health of the population requires a comprehensive study and the subsequent development of normative documents regulating their safe use.

[CHOICE OF SANITARY-INDICATIVE MICROORGANISMS FOR THE ASSESSMENT OF THE SAFETY OF SPLIT-SYSTEMS].

UNLABELLED: Purpose of work is a compilation of data about the microflora which colonizes a split-system, with the aim of selection of sanitary-indicative microorganisms, whose presence in the sample would indicate to the need for cleaning and disinfection of split-systems. MATERIALS AND METHODS: In the article there were used data of five years author's scientific inquiry, related to the prevention of respiratory diseases, associated with the usage of a local air conditioning systems. We also use the data from the literature. RESULTS: For selection of "indicative" microorganisms, we proposed the usage of nine criteria, each of them have numeric value from 0 to 3 points (risk for health, prevalence rate of the disease, epidemiological link, speed of split system's colonization, difficulty of cultivation, resistance in the environment, resistance to disinfectants, frequency of detection in home air conditioning systems, frequency of detection in air conditioning systems of public buildings). After the calculation Pseudomonas aeruginosa and Staphylococcus aureus received maximal score (20 points). Therefore, these two types of bacteria are indicative microorganisms. The detection of these microorganisms in split systems will indicate to the contamination of air-conditioning system. This microflora also is a criterion of cleaning and disinfection quality--presence of these microorganisms in the samples after this process will mean that the processing of air conditioning systems was performed poorly. CONCLUSIONS: Split systems are very faster colonized by conditionally pathogenic and pathogenic microflora. To prevent the possible hazard for population's health it is necessary to develop the normative base, according to which sanitary-and-hygienic control over the split-systems working must be carried out. Proposed criteria suggest that Pseudomonas aeruginosa and Staphylococcus aureus are indicative microorganisms, and it's identification in the air-conditioning system would mean risk for health and necessity for cleaning and disinfection.