scholarly journals Active Filtering and Exchange of Indoor Air by Means of Mobile Air Conditioners to Avoid Infection by The SARS Cov-2 Virus

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Sebastian König
Keyword(s):  
Indoor Air ◽  
Air Conditioners ◽  
Active Filtering

scholarly journals Study on energy loss and thermal environment through door open while air conditioner running

2019 ◽  
Vol 111 ◽  
pp. 06035
Author(s):  
Sihwan Lee
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Room Temperature ◽  
Thermal Environment ◽  
Infiltration Rate ◽  
Operating Efficiency ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Cooling Period ◽  
Closed State

While air conditioner is running, opening doors and windows is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy consumption of air conditioners with door opened and door closed state were measured. The measured results show that the infiltration rate at the door opened state was increased by about 21.3 times compared to the door closed state. When the set temperature of the air conditioner was 24 °C, the room temperature in the opening gate cooling was measured to be about 5 °C higher than the closing gate cooling. However, the energy consumption was measured approximately 12 kWh/day and there was no difference with door state. This means that the energy consumption is not increased if the indoor air temperature would not reach the set point temperature of air conditioner.

Optimization on indoor air diffusion of floor-standing type room air-conditioners

2008 ◽  
Vol 40 (2) ◽  
pp. 59-70 ◽  
Author(s):  
Weiwei Liu ◽  
Zhiwei Lian ◽  
Ye Yao
Keyword(s):  
Indoor Air ◽  
Air Conditioners ◽  
Air Diffusion

scholarly journals Microbial rRNA sequencing analysis of evaporative cooler indoor environments located in the Great Basin Desert region of the United States

2017 ◽  
Vol 19 (2) ◽  
pp. 101-110 ◽  
Author(s):  
Angela R. Lemons ◽  
Mary Beth Hogan ◽  
Ruth A. Gault ◽  
Kathleen Holland ◽  
Edward Sobek ◽  
...  
Keyword(s):  
Great Basin ◽  
Indoor Air ◽  
The United States ◽  
Indoor Environments ◽  
Sequencing Analysis ◽  
Air Conditioners ◽  
Desert Region ◽  
Rrna Sequencing ◽  
Fungal Populations ◽  
Evaporative Cooler

Variations in fungal populations in indoor air were observed between homes cooled by air conditionersversusevaporative cooler systems.

scholarly journals Simplest Way to Establish COVID-19 Quarantine Observation Wards Within 24 Hours

2020 ◽  
Vol 32 (6-7) ◽  
pp. 357-359
Author(s):  
Wen-Nan Huang ◽  
Mao-Song Zhuang ◽  
Tsun-Jen Cheng ◽  
Shih-Huai Hsiao
Keyword(s):  
Health Care ◽  
Indoor Air ◽  
Negative Pressure ◽  
Health Care Facilities ◽  
Government Regulations ◽  
Air Conditioners ◽  
Airborne Infection ◽  
Care Facilities ◽  
General Wards ◽  
Daunting Challenge

Reducing nosocomial transmission within health care facilities is important, but the number of negative-pressure airborne infection isolation rooms for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is limited. It is a daunting challenge to cope with a surge of suspected infectious patients in hospitals. We installed air exhaust fans on the windows to change the pressure direction within the wards rapidly. The best location for the fans was 90 cm from the floor and 90 cm from the edge of bed whether the indoor air conditioners were on or off. The noise level should be <60 dB(A) as per government regulations. General wards can be transformed into makeshift negative-pressure rooms easily and effectively within 24 hours, which is really the simple, fast, and effective way for the transformation being applied.

scholarly journals Assessment of mold infestation of conditioning devices and indoor air

2021 ◽  
Vol 100 (7) ◽  
pp. 668-673
Author(s):  
Elena V. Khaldeeva ◽  
Nadejda I. Glushko ◽  
Svetlana A. Lisovskaya
Keyword(s):  
Air Quality ◽  
Species Diversity ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Continuous Operation ◽  
Large Species ◽  
Air Conditioners ◽  
Air Samples

Introduction. Indoor air quality is an essential component of a healthy human environment. Air conditioning units can affect indoor air quality, including mycogenic contamination of the air if the condition is not adequately monitored. Material and method. The paper presents the results of a mycological study of air samples and flushes from the surface of filters and gratings of air conditioning devices taken from 40 residential and office premises. Results. The presence of micromycetes fungi was noted in 100% of the samples taken from the surface of filters and air conditioning grids and 81.6% of air samples. A greater species diversity of fungi (26 species) was revealed in air samples compared to air conditioning devices (15 species). A higher frequency of occurrence of dark-coloured species of fungi, incl. Aspergillus spp. and Alternaria spp., and fungal species belonging to the third group of pathogenicity, were noticed on the surface of air conditioners, compared with air samples, in which Penicillium spp., Fusarium spp., Trichoderma spp. were more often detected. It was found that the surface of air conditioners functioned sporadically. For a short time (28 rooms), there is a large species diversity of mycobiota at a low or moderate level of seeding (no more than 103 CFU). In rooms with long-term continuous air conditioners (12 rooms), a high level of seeding (more than 104 CFU) by 1-2 species of fungi was more often noted. The existence of a close relationship, confirmed by the values of the Pearson contingency coefficient, between the species composition of the mycobiota of air conditioning devices and air, and a higher level of mycogenic contamination in rooms with long-term continuous operation of air conditioners, were shown. Conclusion. Thus, air conditioning devices can be a source of mycogenic air contamination, especially during long-term continuous operation, which must be taken into account to ensure indoor air quality.

scholarly journals Study on the Cooling Effect of Window Gardens

2020 ◽  
Vol 172 ◽  
pp. 24009
Author(s):  
Jing Ren ◽  
Ming fang Tang
Keyword(s):  
Surface Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Building Envelope ◽  
Air Conditioners ◽  
Interior Surface ◽  
Average Temperature ◽  
Air Temperatures ◽  
Physiological Benefits ◽  
The Impact

Window gardens are known to provide a window view with psychological and physiological benefits, whether they can be used for passive cooling of buildings remains to be investigated. This paper aims to supplement the impact of window gardens on the thermal performance of windows, walls, and even indoor air temperatures, which previous research has ignored. A field experiment was conducted for two classrooms with integrated planting troughs outside the windows, with and without living plants. The indoor air temperature and the interior surface temperature of the two classrooms were measured on a typical hot summer day, with windows closed and air conditioners switched off. The results show that: Window garden with living plants can not only reduce the average temperature of the indoor air by 1.1 ℃, but also reduce the average temperature of the interior surface of the building envelope by 2.8 ℃, the reduction of interior surface temperature is more obvious, which is due to the formation of a cold bridge. Therefore, Window garden can improve the summer indoor thermal environment in hot summer and warm winter area in China.

Performance Comparison of a Truck Refrigeration System with R404A, R134a, R1234yf, and R744 Refrigerants under Frosting Conditions

2016 ◽  
Vol 24 (01) ◽  
pp. 1650005 ◽  
Author(s):  
Yunchan Shin ◽  
Honghyun Cho
Keyword(s):  
Analytical Model ◽  
Indoor Air ◽  
System Performance ◽  
Operating Time ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Average Error ◽  
Refrigeration System ◽  
Air Conditioners

A new refrigerant is needed because the GWP of the R404A and R134a that are used in existing refrigerated trucks and automotive air conditioners is so high. This study predicts cooling performance by using an analytical model, for refrigeration systems using R404A and R134a. Furthermore, the performances of those systems were compared with those of alternative refrigeration systems using R1234yf and R744. The performance data of the analytical model had a trend similar to that of the experimental data: the average error between the analytical and experimental results was within 5.4%. The frost thickness of the R404A system for all operating conditions was about 2.4–3.7% larger than that of other systems because the evaporating temperature of the R404A system was lower than that for other refrigerants. For various operating conditions, the coefficient of performance (COP) of the R134a system was higher than that of other systems, while the R744 system showed the lowest performance. However, the COP reduction of the R744 system with operating time was the smallest because the thermodynamic properties of R744 were very superior. In addition, the frost thickness was seriously affected by the variations of indoor air temperature and compressor rotation speeds, and the system performance decreased significantly for severe operating conditions.

Proposal and System Design for a Chemical Dehumidification Process

2011 ◽  
Author(s):  
Koichi Shirai ◽  
Yukihiko Matsumura ◽  
Hiroyuki Kitahara
Keyword(s):  
Mass Transfer ◽  
System Design ◽  
Sodium Carbonate ◽  
Indoor Air ◽  
Reaction Rate ◽  
Water Transfer ◽  
Dew Point ◽  
Hydration Reaction ◽  
Air Conditioners ◽  
System Energy

When used to dehumidify indoor air, ordinary air-conditioners demand abundant energy and expend it inefficiently. The mechanism of dehumidification on which they rely, the cooling of air to below its dew point to remove moisture by condensation, significantly limits the efficiency, as the air reheats once the moisture is removed. To solve this problem, our group has proposed to use desiccant. The system dehumidifies air using sodium carbonate monohydrate, a chemical that absorbs moisture and changes into decahydrate at low temperature. The compound polyethylene glycol (PEG) is added to the system as a water-transfer medium to increase the contact between the air and sodium carbonate hydrates. In earlier work our group proposed a basic system design and evaluated its efficiency. In doing so, we identified three important points neglected in the design: the power consumption for the circulation pump, the mass transfer characteristics of the spray column, and the hydration reaction rate. In the current study we evaluate a renewed design for the proposed chemical humidity-conditioning system taking these points into account. According to calculations of the system energy balance, the system enables dehumidification with higher COP by 1.5, and practical rates of mass transfer and hydration are expected from the experimental results.

scholarly journals LEVELS OF SELECTED INDOOR AIR POLLUTANTS IN THREE HA NOI OFFICES

2018 ◽  
Vol 56 (2C) ◽  
pp. 148-156 ◽  
Author(s):  
Ly Bich Thuy
Keyword(s):  
Indoor Air ◽  
High Frequency ◽  
Air Pollutants ◽  
Sampling Site ◽  
High Time Resolution ◽  
Air Conditioners ◽  
Dry Seasons ◽  
Indoor Air Pollutants ◽  
Respirable Particulate ◽  
Wet And Dry Seasons

A study on the levels of indoor air pollutants in Ha Noi was conducted. Three offices in Ha Noi were selected for this purpose. Selected indoor air pollutants including SO2, NO2 and respirable particulate matter (PM10) were monitored in the wet and dry seasons of 2015. Air conditioners were turned on for the whole time, while air purifiers were turned on for haft of the time in each sampling site. An hourly measurement of outdoor levels was also conducted before indoor measurement. Levels of outdoor PM10 varied in the range of 13.4-106.0 µg/m3. The level of indoor PM10 varied in the range of 3.5-25.1 µg/m3. The average levels of indoor PM10 were lower than that of outdoor one in all cases. High time resolution data showed that indoor PM10 levels temporarily increased sharply by activities (walking and room sweeping) and high frequency of opening the doors. Concentrations of outdoor/indoor SO2 varied in the range of             < 0.4-34.5 /< 0.4-47.1 ppb. Concentrations of outdoor/indoor NO2 varied in the range of              4.3-33.4/3.3-27.8 ppb.

Sign in / Sign up

Export Citation Format

Share Document