scholarly journals Implications of increasing household air conditioning use across the United States under a warming climate

2021 ◽  
Author(s):  
Renee Obringer ◽  
Roshanak Nateghi ◽  
Debora Maia‐Silva ◽  
Sayanti Mukherjee ◽  
Vineeth CR ◽  
...  
Keyword(s):  
United States ◽  
Air Conditioning ◽  
The United States ◽  
Warming Climate

scholarly journals Differing trends in United States and European severe thunderstorm environments in a warming climate

2020 ◽  
pp. 1-51 ◽  
Author(s):  
Mateusz Taszarek ◽  
John T. Allen ◽  
Harold E. Brooks ◽  
Natalia Pilguj ◽  
Bartosz Czernecki
Keyword(s):  
United States ◽  
The United States ◽  
Severe Thunderstorm ◽  
Low Level ◽  
Warming Climate ◽  
Southern Central ◽  
Convective Inhibition

Capsule summaryStronger convective inhibition causes a decline in the frequency of thunderstorms over the United States, while a substantial increase in low-level moisture supports more thunderstorms over southern, central and northern parts of Europe.

Heat Waves and Innovation in Air Conditioning in the United States

2021 ◽  
Keyword(s):  
United States ◽  
Air Conditioning ◽  
Heat Waves ◽  
Heat Exposure ◽  
The United States ◽  
Extreme Heat ◽  
Weather Data ◽  
County Level ◽  
Similar Increase ◽  
Patent Data

AbstractThis study investigates whether extreme heat episodes (heatwaves) have contributed to the development of air conditioning technology in the United States. To this end we use weather data to identify days at which heat and relative humidity were above levels comfortable to the human body, and match these with patent data at the county level for nearly a hundred years. We find that in the two years after a county has experienced extreme heat air-conditioning patents increase. Overall, average extreme heat exposure results in an increase of 7.5% greater innovation. We find no similar increase in the frequency of non-air conditioning related patent filings, and therefore conclude that heatwaves result in innovation targeting their mitigation.

scholarly journals Trends in Extreme Apparent Temperatures over the United States, 1949–2010

2011 ◽  
Vol 50 (8) ◽  
pp. 1650-1653 ◽  
Author(s):  
Andrew Grundstein ◽  
John Dowd
Keyword(s):  
United States ◽  
Health Outcomes ◽  
Environmental Conditions ◽  
Social Vulnerability ◽  
Air Conditioning ◽  
The United States ◽  
Western United States ◽  
Apparent Temperature ◽  
Clear Increase ◽  
Related Mortality

AbstractBiometeorological indices, such as the apparent temperature, are widely used in studies of heat-related mortality to quantify the human sensation to the environmental conditions. Increases in the frequency of environmentally stressful days as indicated by biometeorological indices may augment the risk for heat-related morbidity and mortality. This study examines trends in the frequency of days with extreme maximum and minimum apparent temperatures across the United States for 1949–2010. An increase in occurrence of 1-day extreme minimum apparent temperatures is particularly notable, especially in the eastern and western United States, with 44% of stations exhibiting positive trends. About 20% of stations have positive trends in 1-day extreme maximum apparent temperature, mostly in the western United States. The median trend for both 1-day extreme maximum and minimum apparent temperature is approximately 2 days per 10 yr, indicating that by 2010 there were 12 more days with extreme apparent temperatures than there were in 1949. Few stations with trends in 4-day extreme minimum or maximum apparent temperatures were noted. An important finding is that there has been a 53% increase in stations with positive trends in 1-day extreme minimum apparent temperatures and a 63% increase in stations with positive trends in 1-day extreme maximum apparent temperatures since a similar study by Gaffen and Ross was conducted using the period 1949–95. Although there is a clear increase in the hazard for days with extreme apparent temperatures, changes in health outcomes are modulated by factors, such as the age of the population and access to air conditioning, that affect social vulnerability.

scholarly journals Dominance of Gas-Eating, Biofilm-Forming Methylobacterium Species in the Evaporator Cores of Automobile Air-Conditioning Systems

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Chulwoo Park ◽  
Hye Su Jung ◽  
Soyoon Park ◽  
Che Ok Jeon ◽  
Woojun Park
Keyword(s):  
United States ◽  
South Korea ◽  
United Arab Emirates ◽  
Biofilm Formation ◽  
Air Conditioning ◽  
Community Analysis ◽  
The United States ◽  
Volatile Organic ◽  
Air Conditioning Systems ◽  
Automobile Air Conditioning

ABSTRACT Microbial communities in the evaporator core (EC) of automobile air-conditioning systems have a large impact on indoor air quality, such as malodor and allergenicity. DNA-based microbial population analysis of the ECs collected from South Korea, China, the United States, India, and the United Arab Emirates revealed the extraordinary dominance of Methylobacterium species in EC biofilms. Mixed-volatile organic compound (VOC) utilization and biofilm-forming capabilities were evaluated to explain the dominance of Methylobacterium species in the ECs. The superior growth of all Methylobacterium species could be possible under mixed-VOC conditions. Interestingly, two lifestyle groups of Methylobacterium species could be categorized as the aggregator group, which sticks together but forms a small amount of biofilm, and the biofilm-forming group, which forms a large amount of biofilm, and their genomes along with phenotypic assays were analyzed. Pili are some of the major contributors to the aggregator lifestyle, and succinoglycan exopolysaccharide production may be responsible for the biofilm formation. However, the coexistence of these two lifestyle Methylobacterium groups enhanced their biofilm formation compared to that with each single culture. IMPORTANCE Air-conditioning systems (ACS) are indispensable for human daily life; however, microbial community analysis in automobile ACS has yet to be comprehensively investigated. A bacterial community analysis of 24 heat exchanger fins from five countries (South Korea, China, the United States, India, and the United Arab Emirates [UAE]) revealed that Methylobacterium species are some of the dominant bacteria in automobile ACS. Furthermore, we suggested that the predominance of Methylobacterium species in automobile ACS is due to the utilization of mixed volatile organic compounds and their great ability for aggregation and biofilm formation.

Fault Tree Analysis for Exposure to Refrigerants Used for Automotive Air Conditioning in the United States

Risk Analysis ◽  
2001 ◽  
Vol 21 (1) ◽  
pp. 157-171 ◽  
Author(s):  
James J. Jetter ◽  
Reynaldo Forte, Jr. ◽  
Reva Rubenstein
Keyword(s):  
United States ◽  
Air Conditioning ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
The United States ◽  
Tree Analysis ◽  
Automotive Air Conditioning

scholarly journals Contrasting scaling relationships of extreme precipitation and streamflow to temperature across the United States

2021 ◽  
Author(s):  
Mingxi Shen ◽  
Ting Fong May Chui
Keyword(s):  
United States ◽  
Extreme Precipitation ◽  
Daily Precipitation ◽  
Temporal Evolution ◽  
Extreme Event ◽  
The United States ◽  
Scaling Analysis ◽  
Southern Plains ◽  
Scaling Relationships ◽  
Warming Climate

Abstract Recent studies have reached inconsistent conclusions from scaling analysis about whether flood or extreme precipitation is more sensitive to warming climate. To explain the reasons behind the inconsistency, here we first used scaling analysis to illustrate how extreme daily precipitation and streamflow scale with daily air temperature across the Continental United States (CONUS). We found both similar and opposite scaling in extreme precipitation and streamflow. It indicates based on scaling analysis, the sensitivity of extreme streamflow to warming climate can be either similar, higher or lower to that of extreme precipitation. We further explored why there are contrasting scaling relationships in the CONUS. Generally, the similar scaling was found in regions where the timing of extreme precipitation and streamflow is correspondent, as well as with similar temporal evolution in extreme event timing and magnitude, e.g., the west coast and southern plains, implying extreme precipitation is the dominant driver of local floods. However, for regions with dissimilar scaling in extreme precipitation and streamflow (e.g., Rocky Mountains, southern plains), the characteristics of extreme streamflow show large difference to those of extreme precipitation, and the temporal evolution of extreme streamflow timing and magnitude are more correlated with factors/processes such as soil moisture and snowmelt. This study reflects that the contrasting scaling relationships of extreme precipitation and streamflow are oriented from the local hydro-climatological specifics. Using scaling analysis to compare the sensitivity of extreme precipitation and streamflow to warming climate is not suitable. Instead, we should focus more on local flood generating mechanisms or flood drivers when investigating floods in the changing climate.

scholarly journals Operational Performance Characterization of a Heat Pump System Utilizing Recycled Water as Heat Sink and Heat Source in a Cool and Dry Climate

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 211 ◽  
Author(s):  
Piljae Im ◽  
Xiaobing Liu ◽  
Hugh Henderson
Keyword(s):  
United States ◽  
Energy Consumption ◽  
Heat Pump ◽  
Air Conditioning ◽  
The United States ◽  
Heat Pumps ◽  
Recycled Water ◽  
Pump System ◽  
Performance Characterization ◽  
Heat Pump System

The wastewater leaving from homes and businesses contains abundant low-grade energy, which can be utilized through heat pump technology to heat and cool buildings. Although the energy in the wastewater has been successfully utilized to condition buildings in other countries, it is barely utilized in the United States, until recently. In 2013, the Denver Museum of Nature & Science at Denver, the United States implemented a unique heat pump system that utilizes recycled wastewater from a municipal water system to cool and heat its 13,000 m2 new addition. This recycled water heat pump (RWHP) system uses seven 105 kW (cooling capacity) modular water-to-water heat pumps (WWHPs). Each WWHP uses R-410A refrigerant, has two compressors, and can independently provide either 52 °C hot water (HW) or 7 °C chilled water (CHW) to the building. This paper presents performance characterization results of this RWHP system based on the measured data from December 2014 through August 2015. The annual energy consumption of the RWHP system was also calculated and compared with that of a baseline Heating, Ventilation, and Air Conditioning (HVAC) system which meets the minimum energy efficiencies that are allowed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013. The performance analysis results indicate that recycled water temperatures were favorable for effective operation of heat pumps. As a result, on an annual basis, the RWHP system avoided 50% of source energy consumption (resulting from reduction in natural gas consumption although electricity consumption was increased slightly), reduced CO2 emissions by 41%, and saved 34% in energy costs as compared with the baseline system.

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