scholarly journals Thermal Mitigation of the Indoor and Outdoor Climate by Green Curtains in Japanese Condominiums

Climate ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Hiroto Abe ◽  
Hom B. Rijal ◽  
Ryoga Hiroki ◽  
Kentaro Iijima ◽  
Akira Ohta
Keyword(s):  
Thermal Comfort ◽  
Green Infrastructure ◽  
Energy Use ◽  
Air Conditioner ◽  
Outdoor Climate ◽  
Globe Temperature ◽  
Thermal Mitigation ◽  
Mitigation Methods ◽  
Reducing Energy ◽  
Indoor And Outdoor

In recent years, “green curtains” have become one of the most prevalent thermal mitigation methods in Japan. They can be considered as green infrastructure for achieving thermal comfort and reducing energy use. To examine the thermal mitigation effect of the green curtain for practical applicability in the condominium, the indoor and balcony temperatures for 48 days both in households with and without green curtains were analyzed. The balcony globe temperature of the households with green curtains was 0.6 °C lower than that of the households without green curtains, during air-conditioner usage. Furthermore, the air-conditioner usage time of the households with green curtains was 40% less than that of the households without green curtains. The results showed that green curtains are effective for achieving both thermal mitigation and energy saving in a condominium.

scholarly journals A Comprehensive Thermal Comfort Analysis of the Cooling Effect of the Stand Fan Using Questionnaires and a Thermal Manikin

2019 ◽  
Vol 11 (18) ◽  
pp. 5091 ◽  
Author(s):  
Mun ◽  
Kwak ◽  
Kim ◽  
Huh
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Thermal Sensation ◽  
Convective Heat Transfer Coefficient ◽  
Cooling Effect ◽  
Primary Data ◽  
Thermal Manikin ◽  
Air Conditioner ◽  
Data Set ◽  
Personal Cooling

In this study a quantitative analysis was performed on the effect on thermal comfort of the stand fan, a personal cooling device that creates local air currents. A total of 20 environmental conditions (indoor temperatures: 22, 24, 26, 28, and 30°C; fan modes: off, low (L) mode, medium (M) mode, and high (H) mode) were analyzed using questionnaires on male and female subjects in their 20s and a thermal manikin test. The contents of the questionnaire consisted of items on thermal sensation, thermal comfort, thermal acceptability, and demands on changes to the air velocity. This step was accompanied by the thermal manikin test to analyze the convective heat transfer coefficient and cooling effect quantitatively by replicating the stand fan. Given that this study provides data on the cooling effect of the stand fan in quantitative values, it allows for a comparison of energy use with other cooling systems such as the air conditioner, and may be used as a primary data set for analysis of energy conservation rates.

scholarly journals Thermal Comfort Aspects of Solar Gains during the Heating Season

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1702 ◽  
Author(s):  
Ferenc Kalmár ◽  
Tünde Kalmár
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Winter Season ◽  
Diffuse Radiation ◽  
Heating Season ◽  
Negative Effects ◽  
Thermal Discomfort ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature ◽  
Personalized Ventilation

Glazing plays a key role in the energy balance of buildings. The aim of this paper is to enlighten the thermal discomfort caused by large glazed areas in the heating season and to point out a possible solution that can provide proper thermal comfort with low energy use. It is unusual to discuss the negative effects of solar gains on thermal comfort during the heating season. However, there are cases when glazing may lead to unforeseen indoor thermal discomfort conditions. Laboratory and on site measurements were performed in order to assess thermal discomfort caused by direct and diffuse radiation. It was shown that the WBGT (Wet Bulb Globe Temperature) index may exceed even 30 °C in the winter season in a room having large glazed area oriented to east. Laboratory tests performed in climate chamber have shown that the high PMV values cannot be reduced below 1.0, increasing the air change rate in the room. Using opaque drapes, the WBGT index was reduced by 2 °C, but the daylighting decreased substantially. It was demonstrated that by using advanced personalized ventilation systems, the appropriate thermal comfort can be provided avoiding the reduction of daylighting.

Investigation of the cooling performance and thermal comfort for 4-way cassette air conditioner with swinging motion of vanes

2021 ◽  
Vol 35 (4) ◽  
pp. 1757-1770
Author(s):  
Ho Yeon Choi ◽  
Jae Hyun Oh ◽  
Man Su Park ◽  
Sai Kee Oh ◽  
Yong Gap Park ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Conditioner ◽  
Cooling Performance

scholarly journals Impacts on Indoor Thermal Comfort and Heating Energy Use in Hellenic Dwellings from Occupant Behavioral Reactions

2021 ◽  
Vol 11 (14) ◽  
pp. 6254
Author(s):  
Elena G. Dascalaki ◽  
Constantinos A. Balaras
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Energy Savings ◽  
Local Heating ◽  
Economic Recession ◽  
Heating System ◽  
Building Stock ◽  
Heating Systems ◽  
Indoor Thermal Comfort ◽  
Energy Audits

In an effort to reduce the operational cost of their dwellings, occupants may even have to sacrifice their indoor thermal comfort conditions. Following the economic recession in Greece over recent years, homeowners have been forced to adapt their practices by shortening heating hours, lowering the indoor thermostat settings, isolating spaces that are not heated or even turning off their central heating system and using alternative local heating systems. This paper presents the results from over 100 occupant surveys using questionnaires and walk-through energy audits in Hellenic households that documented how occupants operated the heating systems in their dwellings and the resulting indoor thermal comfort conditions and actual energy use. The results indicate that the perceived winter thermal comfort conditions were satisfactory in only half of the dwellings, since the actual operating space heating periods averaged only 5 h (compared with the assumed 18 h in standard conditions), while less than half heated their entire dwellings and only a fifth maintained an indoor setpoint temperature of 20 °C, corresponding to standard comfort conditions. Mainstream energy conservation measures include system maintenance, switching to more efficient systems, reducing heat losses and installing controls. This information is then used to derive empirical adaptation factors for bridging the gap between the calculated and actual energy use, making more realistic estimates of the expected energy savings following building renovations, setting prudent targets for energy efficiency and developing effective plans toward a decarbonized building stock.

Water, land, and energy use efficiencies and financial evaluation of air conditioner cooled greenhouses based on field experiments

2021 ◽  
Author(s):  
Ibtihal Al-Manthria ◽  
Abdulrahim M. Al-Ismailia ◽  
Hemesiri Kotagamab ◽  
Mumtaz Khanc ◽  
L. H. Janitha Jeewanthad
Keyword(s):  
Energy Use ◽  
Field Experiments ◽  
Air Conditioner ◽  
Financial Evaluation

Optimizing Thermal Comfort and Energy Use for Learning Environments

2021 ◽  
pp. 111181
Author(s):  
Mary Taylor ◽  
Nathan Brown ◽  
Donghyun Rim
Keyword(s):  
Thermal Comfort ◽  
Learning Environments ◽  
Energy Use

scholarly journals Efficiency Enhancement on Thermal Comfort Assessment of Indoor Space with Air-Conditioner Using Computational Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Yu-Tuan Chou ◽  
Shao-Yi Hsia ◽  
Bi-Wen Lee
Keyword(s):  
Taguchi Method ◽  
Thermal Comfort ◽  
Flow Simulation ◽  
Successful Implementation ◽  
Outlet Temperature ◽  
Air Conditioner ◽  
Indoor Space ◽  
Factorial Method ◽  
Operation Conditions ◽  
Full Factorial

Thermal comfort providing is one of the biggest uses of energy in building. For giving better human comfort, the suitable operation conditions of air-conditioner are the most important. The quick and right approach is necessary. In this paper, a small office is studied to improve office staff staying for a long period of time and achieve the thermal comfort environment for reducing energy consumption. Commercial software, Solidworks, is utilized for modeling the facilities and the Flow Simulation module for analyzing the air properties of the indoor space. Four types of air-conditioner operation are applied to set the simulated conditions, including exterior temperature, outlet temperature and wind speed of air-conditioner, and location of air-conditioner. Predicted mean vote (PMV) and predicted percent dissatisfied (PPD) at specific office areas are further acquired through dynamic anthropometry. For seeking the optimal control factors, both of the full factorial method and Taguchi method are utilized to obtain the PMV of specified location. The analyzed result shows the evaluation speed of indoor thermal comfort by Taguchi method is faster than the full-factorial method. It is concluded that software simulation with Taguchi method shows the successful implementation and higher efficiency for thermal comfort assessment.

scholarly journals Thermal performance and concentration of gases in facilities for pigs in semiarid region from State of Paraiba - Brazil

2012 ◽  
Vol 32 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Dermeval A. Furtado ◽  
Daniele Amancio ◽  
José W. B. do Nascimento ◽  
Josivanda P. Gomes ◽  
Rafael C. Silva
Keyword(s):  
Carbon Monoxide ◽  
Thermal Comfort ◽  
Rainy Season ◽  
Dry Season ◽  
International Standards ◽  
Semiarid Region ◽  
Thermal Discomfort ◽  
Rainy Period ◽  
Globe Temperature ◽  
The Times

The study was conducted in a facility for pigs during the nursery and finishing in the town of 'Montadas', in the semiarid of the state of Paraiba, Brazil, in the rainy and dry season, aiming to evaluate the concentration of oxygen, methane, carbon monoxide and ammonia, and the bioclimatic indexes: ambient temperature (AT), relative humidity (RH) and the index of black globe temperature and humidity (IBGTH). These indexes differed significantly (P>0.05) between the periods and times. The AT in the rainy season was in the thermal comfort zone(TCZ) in most of the times in the nursery; for the finishing phase, thermal discomfort occurred; during the dry season, there was thermal comfort in the nursery phase; in the finishing phase the thermal discomfort occurred at all times. In the rainy season, the IBGTH was in TCZ; in the dry season, it was above the TCZ. The RH in the rainy period was in the TCZ; in the dry season, in most of the times, below the range of the TCZ. The concentration of gases showed no differences (P > 0.05) between periods and between the times, and the carbon monoxide, hydrogen sulfide and methane were below 1.0 ppm, and the ammonia showed a mean of 5.2 ppm. None of the analyzed gases exceeded the limits established by Brazilian and international standards for animals and workers.

scholarly journals The efficiency of a dynamically insulated wall in the presence of air leakages

2004 ◽  
Vol 8 (1) ◽  
pp. 83-94
Author(s):  
Angela Kalagasidis-Sasic
Keyword(s):  
System Analysis ◽  
Ventilation System ◽  
Building Envelope ◽  
Leading Role ◽  
Outdoor Climate ◽  
Dynamic Insulation ◽  
Building Components ◽  
Heat And Moisture ◽  
Alternative Designs ◽  
Indoor And Outdoor

The movement of air in and through the building envelope often plays a leading role in the transport of heat and moisture into the building. It is caused by pressure and temperature variations around the building envelope inbuilt ventilation system, occupancy, etc. In order to improve the energy consumption, alternative designs for the ventilation systems are considered. One of them is a dynamically insulated wall as an inlet unit for the supplying air. In order to predict the performance of a dynamically insulated wall, it is necessary to make an analysis of the building as a system. This paper presents such system analysis which takes into account the interaction between the building components and indoor and outdoor climate, both in terms of the air leakage and heat and mass transfer to and from the building components. It is shown that, in the presence of air leakages (unintentional openings) in the enclosure of the building, the efficiency of the dynamic insulation is significantly decreased.

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