Managing heat rejected from air conditioning systems to save energy and improve the microclimates of residential buildings

2011 ◽  
Vol 35 (5) ◽  
pp. 358-367 ◽  
Author(s):  
Chun-Ming Hsieh ◽  
Toshiya Aramaki ◽  
Keisuke Hanaki
Keyword(s):  
Air Conditioning ◽  
Residential Buildings ◽  
Save Energy ◽  
Air Conditioning Systems

scholarly journals Solar hybrid air conditioning system to use in Iraq to save energy

2019 ◽  
Vol 124 ◽  
pp. 01024
Author(s):  
Y. V. Vankov ◽  
A. K. Al–Okbi ◽  
M. H. Hasanen
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Electricity Consumption ◽  
Air Conditioners ◽  
Reduce Electricity Consumption ◽  
Central Air Conditioning ◽  
Save Energy ◽  
Air Conditioning Systems

The energy saving issues are becoming necessary worldwide, as excessive consumption of energy leads to the consumption of a larger amount of fuel, increases environmental pollution and negatively affects the ozone layer. In Iraq, in particular, the demand for central air conditioning systems and home air conditioners with high electrical capacity has become increasingly clear in the recent years. Air conditioning systems within residential and public buildings, as well as government facilities became a necessity for good internal comfort, which was driven by desertification, high temperature, air pollution and increased population, resulting in increased consumption of electric power and pressing of power plants. Aiming at usage of renewable energy sources, the proposed system uses solar collectors as auxiliary solar thermal compressors and integrate them with air conditioning systems. The proposed solution will increase the cooling system efficiency, reduce electricity consumption and pollution.

scholarly journals The Significance of the Adaptive Thermal Comfort Limits on the Air-Conditioning Loads in a Temperate Climate

2019 ◽  
Vol 11 (2) ◽  
pp. 328 ◽  
Author(s):  
Aiman Albatayneh ◽  
Dariusz Alterman ◽  
Adrian Page ◽  
Behdad Moghtaderi
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Temperate Climate ◽  
Heating And Cooling ◽  
Air Temperatures ◽  
Adaptive Thermal Comfort ◽  
Save Energy ◽  
One Year ◽  
Air Conditioning Systems ◽  
Thermal Comfort Model

The building industry is regarded a major contributor to climate change as energy consumption from buildings accounts for 40% of the total energy. The types of thermal comfort models used to predict the heating and cooling loads are critical to save energy in operative buildings and reduce greenhouse gas emissions (GHG). In this research, the internal air temperatures were recorded for over one year under the free floating mode with no heating or cooling, then the number of hours required for heating or cooling were calculated based on fixed sets of operative temperatures (18 °C–24 °C) and the adaptive thermal comfort model to estimate the number of hours per year required for cooling and heating to sustain the occupants’ thermal comfort for four full-scale housing test modules at the campus of the University of Newcastle, Australia. The adaptive thermal comfort model significantly reduced the time necessary for mechanical cooling and heating by more than half when compared with the constant thermostat setting used by the air-conditioning systems installed on the site. It was found that the air-conditioning system with operational temperature setups using the adaptive thermal comfort model at 80% acceptability limits required almost half the operating energy when compared with fixed sets of operating temperatures. This can be achieved by applying a broader range of acceptable temperature limits and using techniques that require minimal energy to sustain the occupants’ thermal comfort.

scholarly journals Impact Assessment of the ventilation systems on microbiological safety and microclimatic conditions of premises.

2020 ◽  
pp. 49-55
Author(s):  
Tetiana Kryvomaz ◽  
Dmytro Varavin ◽  
Rostyslav Sipakov
Keyword(s):  
Air Conditioning ◽  
Residential Buildings ◽  
Operating Conditions ◽  
International Agencies ◽  
Industrial Buildings ◽  
Key Factor ◽  
Poor Ventilation ◽  
Air Conditioning Systems ◽  
The Impact ◽  
Ventilation Systems

The critical aspects of the impact of microbiological contamination on ventilation and air conditioning systems, the microclimate of the premises, and human health are analyzed. The quantitative and qualitative composition of the microflora of premises depends on their functional purpose, design features, operating conditions, climate, and other factors, among which the method of ventilation is essential. The moisturizers in the air conditioning system are hazardous, which provide bacteria and fungi with water necessary for their life and reproduction. In addition, contaminants accumulated in ventilation systems operate as a substrate for feeding microorganisms. Multi-story administrative, public, and residential buildings, industrial buildings, and other places of mass concentration are areas of increased aerobiological risk of infection. In case of improper operation, air conditioning and ventilation systems can be sources of microorganisms in any room. Transmission of infectious aerosol over long distances occurs in rooms with poor ventilation, and a key factor for the outbreak of infection is the direction of airflows. In the context of the COVID-19 pandemic, organizations and international agencies to control the spread of SARS-CoV-2 indoors recommend limiting the operation of exhaust ventilation and recirculation systems. However, there is still insufficient data to clarify the role of heating, ventilation, and air conditioning systems in spreading infection. Risk assessment and decision-making on the choice of air conditioning systems should be dynamic and based on the scale of the pandemic and the verification of the characteristics of HVAC systems and their effectiveness.

scholarly journals Energy-Saving Potential of Thermal Diode Tank Assisted Refrigeration and Air-Conditioning Systems

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 206
Author(s):  
Mingzhen Wang ◽  
Eric Hu ◽  
Lei Chen
Keyword(s):  
Ambient Temperature ◽  
Energy Saving ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Weather Data ◽  
Water Tank ◽  
Previous Night ◽  
Baseline System ◽  
Save Energy ◽  
Air Conditioning Systems

Lowering the condensing temperature of the Refrigeration and Air-conditioning (RAC) system has been proven to effectively increase the system’s Coefficient of Performance (COP). This paper revolves around evaluating the energy-saving generated by applying a Thermal Diode Tank (TDT) in the RAC systems. The TDT is a novel invention, which is an insulated water tank equipped with gravity heat pipes. If the TDT was placed outdoors overnight, its inside water would theoretically be at the minimum ambient temperature of the previous night. When the TDT water is used to cool the condenser of RAC systems that operate during the daytime, a higher COP of this TDT assisted RAC (TDT-RAC) system could be achieved compared with the baseline system. In this study, a steady-state performance simulation model for TDT-RAC cycles has been developed. The model reveals that the COP of the TDT-RAC cycle can be improved by 10~59% over the baseline cycle depending on the compressor types. The TDT-RAC cycle with a variable speed compressor can save more energy than that with a fixed speed compressor. In addition, TDT-RAC cycles can save more energy with a higher day/night ambient temperature difference. There is a threshold tank size for a given TDT-RAC cycle to save energy, and the energy-saving can be improved by enlarging the tank size. A desk-top case study based on real weather data for Adelaide in January 2021 shows that 9~40% energy could be saved by TDT-RAC systems every summer day on average.

scholarly journals Maintaining Comfortable Summertime Indoor Temperatures by Means of Passive Design Measures to Mitigate the Urban Heat Island Effect—A Sensitivity Analysis for Residential Buildings in the City of Vienna

Urban Science ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 66 ◽  
Author(s):  
Doris Österreicher ◽  
Stefan Sattler
Keyword(s):  
Urban Heat Island ◽  
Air Conditioning ◽  
Residential Buildings ◽  
Urban Heat Island Effect ◽  
Heat Island ◽  
Island Effect ◽  
Passive Design ◽  
Urban Heat ◽  
Air Conditioning Systems ◽  
The City

The waste heat generated from the use of air conditioning systems in cities significantly contributes to the urban heat island effect (UHI) during the summer months. Thus, one of the key measures to mitigate this effect is to limit the use of active cooling systems. In the city of Vienna, air conditioning units are common in nonresidential buildings, but have so far been much less installed in residential buildings. This is mainly due to the fact that the Viennese summertime climate is still considered to be relatively comfortable and planning guidelines related to energy efficiency are already strict, resulting in high-quality buildings in regard to thermal performance. However, during the last decade, an increase in summertime temperatures and so called “tropical nights” has been recorded in Vienna and subsequently the postconstruction installation of air conditioning systems in residential buildings has significantly increased. In a study undertaken for the City of Vienna, a series of passive design measures have been simulated with current and future climate scenarios in order to determine the most effective combination of architecturally driven actions to avoid the use of air conditioning systems in residential buildings whilst maintaining comfortable indoor temperatures.

Predictive control of multizone heating, ventilation and air-conditioning systems in non-residential buildings

2015 ◽  
Vol 37 ◽  
pp. 847-862 ◽  
Author(s):  
Antoine Garnier ◽  
Julien Eynard ◽  
Matthieu Caussanel ◽  
Stéphane Grieu
Keyword(s):  
Predictive Control ◽  
Air Conditioning ◽  
Residential Buildings ◽  
Air Conditioning Systems
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