On the Anthropogenic Heat Fluxes Using an Air Conditioning Evaporative Cooling Parameterization for Mesoscale Urban Canopy Models

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Estatio Gutiérrez ◽  
Jorge E. González ◽  
Alberto Martilli ◽  
Robert Bornstein
Keyword(s):  
New York ◽  
Latent Heat ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Urban Canopy ◽  
Heat Fluxes ◽  
Anthropogenic Heat ◽  
Atmospheric Conditions ◽  
Canopy Layer ◽  
Air Conditioning Systems

An air conditioning evaporative cooling parameterization was implemented in a building effect parameterization/building energy model (BEP + BEM) to calculate the magnitude of the anthropogenic sensible and latent heat fluxes from buildings released to the atmosphere. The new heat flux formulation was tested in New York City (NYC) for the summer of 2010. Evaporative cooling technology diminishes between 80% and 90% of the anthropogenic sensible heat from air conditioning systems by transforming it into latent heat in commercial (COMM) areas over NYC. Average 2-m air temperature is reduced by 0.8 °C, while relative humidity is increased by 3% when cooling towers (CTs) are introduced. Additionally, CTs introduce stable atmospheric conditions in the urban canopy layer reducing turbulence production particularly during dry days.

scholarly journals Indoor Air Quality Enhancement Performance of Liquid Desiccant and Evaporative Cooling-Assisted Air Conditioning Systems

2019 ◽  
Vol 11 (4) ◽  
pp. 1036 ◽  
Author(s):  
Beom-Jun Kim ◽  
Junseok Park ◽  
Jae-Weon Jeong
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Reference System ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Quality Enhancement ◽  
Liquid Desiccant ◽  
Air Conditioning Systems ◽  
Indoor Pm2.5

The main objective of this study is to investigate the indoor air quality enhancement performance of two different liquid desiccant and evaporative cooling-assisted air conditioning systems, such as the variable air volume (VAV) system with the desiccant-enhanced evaporative (DEVap) cooler, and the liquid desiccant system with an indirect and direct evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS), compared with the conventional VAV system. The transient simulations of concentration variations of carbon dioxide (CO2), coarse particles, and fine particles (PM10 and PM2.5) in a model office space served by each system were performed using validated system models that were found in the literature. Based on the hourly thermal loads of the model space predicted by the TRNSYS 18 program, each air conditioning system was operated virtually using a commercial equation solver program (EES). The results indicated that the LD-IDECOAS provided the lowest annual indoor CO2 concentration among all the systems considered in this research, while the VAV system with DEVap cooler exceeded the threshold concentration (i.e., 1000 ppm) during the cooling season (i.e., July, August, and September). For the indoor particulate contaminant concentrations, both liquid desiccant and evaporative cooling-assisted air conditioning systems indicated lower indoor PM2.5 and PM10 concentrations compared with the reference system. The LD-IDECOAS and the VAV with a DEVap cooler demonstrated 33.3% and 23.5% lower annual accumulated indoor PM10 concentrations than the reference system, respectively. Similarly, the annual accumulated indoor PM2.5 concentration was reduced by 16% using the LD-IDECOAS and 17.1% using the VAV with DEVap cooler.

scholarly journals Energy Performance Comparison between Two Liquid Desiccant and Evaporative Cooling-Assisted Air Conditioning Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 522
Author(s):  
Su Liu ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Dew Point ◽  
Outdoor Air ◽  
Liquid Desiccant ◽  
Energy Saving Potential ◽  
Evaporative Cooler ◽  
Air Conditioning Systems ◽  
Direct Evaporative Cooler

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.

scholarly journals On the Assessment of a Cooling Tower Scheme for High-Resolution Numerical Weather Modeling for Urban Areas

2019 ◽  
Vol 58 (6) ◽  
pp. 1399-1415 ◽  
Author(s):  
Miao Yu ◽  
Jorge González ◽  
Shiguang Miao ◽  
Prathap Ramamurthy
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Urban Areas ◽  
Cooling Tower ◽  
Absolute Humidity ◽  
Heat Fluxes ◽  
Anthropogenic Heat ◽  
Near Surface ◽  
Anthropogenic Heat Flux ◽  
Temperature Errors

AbstractA cooling tower scheme that quantifies the sensible and latent anthropogenic heat fluxes released from buildings was coupled to an operational forecasting system [Rapid Refresh Multiscale Analysis and Prediction of the Beijing Urban Meteorological Institute (RMAPS-Urban)] and was evaluated in the context of the megacity of Beijing, China, during summer months. The objective of this scheme is to correct for underestimations of surface latent heat fluxes in regional climate modeling and weather forecasts in urban areas. The performance for surface heat fluxes by the modified RMAPS-Urban is greatly improved when compared with a suite of observations in Beijing. The cooling tower scheme increases the anthropogenic latent heat partition by 90% of the total anthropogenic heat flux release. Averaged surface latent heat flux in urban areas increases to about 64.3 W m−2 with a peak of 150 W m−2 on dry summer days and 40.35 W m−2 with a peak of 150 W m−2 on wet summer days. The model performance of near-surface temperature and humidity is also improved. Average 2-m temperature errors are reduced by 1°C, and maximum and minimum temperature errors are improved by 2°–3°C; absolute humidity is increased by 5%.

scholarly journals On the Drag and Heat of Washington, D.C., and New York City

2014 ◽  
Vol 53 (6) ◽  
pp. 1454-1470 ◽  
Author(s):  
Bruce B. Hicks ◽  
William R. Pendergrass ◽  
Christoph A. Vogel ◽  
Richard S. Artz
Keyword(s):  
New York ◽  
New York City ◽  
York City ◽  
Air Conditioning ◽  
Sensible Heat Flux ◽  
Wind Component ◽  
Surface Boundary ◽  
Surface Boundary Layer ◽  
Heating And Cooling ◽  
Air Conditioning Systems

AbstractData from a network of micrometeorological instruments, mostly mounted 10 m above the roofs of 12 buildings in Washington, D.C., are used to derive average values and spatial differences of the normalized local friction velocity u*/u ≡ ()1/2/u (with u being the wind speed reported at the same height as the covariance is measured, w being the vertical wind component, primes indicating deviations, and the overbar indicating averaging). The analysis is extended through consideration of two additional sites in New York City, New York. The ratio u*/u is found to depend on wind direction for all locations. Averaged values of u*/u appear to be best associated with the standard deviation of local building heights, with little evidence of a dependence on any other of the modern building-morphology indices. Temperature covariance data show a large effect of nearby activities, with the consequences of air-conditioning systems being obvious (especially at night) in some situations. The Washington data show that older buildings, built largely of native limestone, show the greatest effects of air-conditioning systems. The assumption that the nighttime surface boundary layer is stable is likely to be most often incorrect for both Washington and New York City—the sensible heat flux resulting from heating and cooling of building work spaces most often appears to dominate.

scholarly journals Optimization of heat and mass transfer processes in air conditioning systems in public buildings

2020 ◽  
Vol 4 (4) ◽  
pp. 49-56
Author(s):  
A. V. Tsygankov ◽  
◽  
V. I. Lysev ◽  
A. K. Rubtsov ◽  
A. S. Shilin ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Experimental Study ◽  
Air Conditioning ◽  
Heat Fluxes ◽  
Public Buildings ◽  
Transfer Processes ◽  
Air Temperatures ◽  
Mass Transfer Processes ◽  
Predicted Values ◽  
Air Conditioning Systems

Increasing the energy efficiency of air conditioning systems in public buildings and structures is an actual task. A mathematical model is proposed for determining the values of internal air temperatures and temperatures of the surfaces of enclosure in order to calculate the predicted values of heat fluxes in buildings and structures. An experimental study has been carried out showing the relevance of the proposed method

scholarly journals The Influence of a Lake-to-Lake Connection from Lake Huron on the Lake-Effect Snowfall in the Vicinity of Lake Ontario

2018 ◽  
Vol 57 (7) ◽  
pp. 1423-1439 ◽  
Author(s):  
Carrie E. Lang ◽  
Jessica M. McDonald ◽  
Lauriana Gaudet ◽  
Dylan Doeblin ◽  
Erin A. Jones ◽  
...  
Keyword(s):  
New York ◽  
New York State ◽  
Lake Ontario ◽  
Heat Fluxes ◽  
Lake Huron ◽  
Atmospheric Conditions ◽  
Near Surface ◽  
Surface Heat Fluxes ◽  
Wind Speeds ◽  
Lake Effect

AbstractLake-effect storms (LES) produce substantial snowfall in the vicinity of the downwind shores of the Great Lakes. These storms may take many forms; one type of LES event, lake to lake (L2L), occurs when LES clouds/snowbands develop over an upstream lake (e.g., Lake Huron), extend across an intervening landmass, and continue over a downstream lake (e.g., Lake Ontario). The current study examined LES snowfall in the vicinity of Lake Ontario and the atmospheric conditions during Lake Huron-to-Lake Ontario L2L days as compared with LES days on which an L2L connection was not present [i.e., only Lake Ontario (OLO)] for the cold seasons (October–March) from 2003/04 through 2013/14. Analyses of snowfall demonstrate that, on average, significantly greater LES snowfall totals occur downstream of Lake Ontario on L2L days than on OLO days. The difference in mean snowfall between L2L and OLO days approaches 200% in some areas near the Tug Hill Plateau and central New York State. Analyses of atmospheric conditions found more-favorable LES environments on L2L days relative to OLO days that included greater instability over the upwind lake, more near-surface moisture available, faster wind speeds, and larger surface heat fluxes over the upstream lake. Last, despite significant snowfalls on L2L days, their average contribution to the annual accumulated LES snowfall in the vicinity of Lake Ontario was found to be small (i.e., 25%–30%) because of the relatively infrequent occurrence of L2L days.

scholarly journals Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

2021 ◽  
Vol 86 (1) ◽  
pp. 140-153
Author(s):  
Azridjal Aziz ◽  
Muhammad Rif’at Syahnan ◽  
Afdhal Kurniawan Mainil ◽  
Rahmat Iman Mainil
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioner ◽  
Direct Evaporative Cooling ◽  
Compressor Power ◽  
Discharge Pressure ◽  
Air Conditioning Systems

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.

Design and Fabrication of Evaporative Cooling Air Conditioner in Tractor Cabin

2019 ◽  
pp. 1-8
Author(s):  
Ramesh P ◽  
Deepak Balaji V ◽  
Ganesh Kumar R ◽  
Aakash Sundar S
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Air Conditioner ◽  
Atmospheric Conditions ◽  
Automotive Air Conditioning ◽  
Key Factor ◽  
Dry Conditions ◽  
History Of ◽  
Cooling Air ◽  
Vapour Compression

The Evolution of automotive air conditioning was a remarkable milestone in the history of mankind. It has played an important role in human comfort and to some extent in human safety during vehicle driving in varied atmospheric conditions. Present work focuses on providing comfort conditioning of a tractor cab which is a key factor in ensuring optimum working performance of the driver. A closed tractor cab acts like a greenhouse and its interior could become unbearable and sometimes even dangerous. Conventionally, vapour compression refrigeration systems are the standard for air conditioning in automobiles and account for up to 25 % of fuel consumption in the cooling season. Apart from conventional vapour compression technology, the work explores applicability of evaporative cooling in comfort conditioning of a tractor cabin which is an economical and eco-friendly alternative. The results procured are positive lower cabin temperature close to acceptable limit with less than 10 % of energy consumption compared to vapour-compression units when tested under similar hot-dry conditions.

Sign in / Sign up

Export Citation Format

Share Document