scholarly journals An efficient climate index for reflecting cooling energy consumption: Cooling degree days based on wet bulb temperature

2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Jingfu Cao ◽  
Mingcai Li ◽  
Ruixue Zhang ◽  
Min Wang
Author(s):  
Mostafa Jafari ◽  
Pete Smith

Heating Degree Days (HDD), in cases where temperatures are below 18°C, and Cooling Degree Days (CDD), in cases where temperatures are above 21°C, were used as energy consumption indices. During the last half century, mean annual temperatures have increased and as a consequence, CDD in the warm season have increased sharply. In the same time slice, HDD, even in the cool and cold season have declined steadily. The number of monthly and annual total HDD (mean= 1556) are much higher than CDD (mean=400) in the case study area and annual total HDD and CDD have a negative correlation (Pearson correlation = - 0.493; p = 0.001). The deceasing rate of HDD is limited and steady (R2= 0.062, p=0.099), but the increasing rate of CDD in the same time slice is sharp (R2=0.427, p=0.813). This shows that energy consumption patterns have increased sharply, and with available projection scenarios, is projected to increase more rapidly, leading to higher energy costs.


2016 ◽  
Vol 38 (3) ◽  
pp. 327-350 ◽  
Author(s):  
Madhavi Indraganti ◽  
Djamel Boussaa

Saudi Arabia’s energy consumption is increasing astronomically. Saudi Building Code prescribes a fixed base temperature of 18.3℃ to estimate the heating degree-days and cooling degree-days. Using historical meteorological data (2005–2014), this article presents the heating degree-days and cooling degree-days estimated for the representative cities in all the five inhabited climatic zones of Saudi Arabia. We used the base temperatures of 14℃, 16℃ and 18℃ for heating degree-days, and 18℃, 20℃, 22℃, 24℃ and 28℃ for cooling degree-days for Dhahran, Guriat, Jeddah, Khamis Mushait and Riyadh cities. We developed multiple regression models for heating degree-days and cooling degree-days at various base temperatures for these zones. Degree-days for other cities in similar climates with limited input data can be computed with these. Lowering of base temperature by 2 K from 18℃ reduced the heating degree-days by 33–65%. At 14℃ of base temperature, the heating requirement reduced by 60–95%. Elevating the base temperature by 2 K from 18℃ lowered the cooling degree-days by 16–38%. At 28℃ of base temperature cooling can be completely eliminated in Khamis Mushait, and reduced by 65–92% in other cities. This observation merits rethinking about use of appropriate base temperatures that properly link the outdoor environment to reduce the energy consumption. Practical application: Using historical data, we developed regression models for predicting heating and cooling degree-days for five cities of Saudi Arabia in various climate zones without the historic data. Using these, we can estimate the changes in heating/cooling load due to the variation in base temperatures. For example, lowering base temperature by 2–4 K from 18℃ reduces the HDDs by 33–95% and elevating the base temperature by 2–4 K from 18℃ lowered the CDDs by 16–68%.


Author(s):  
Mostafa Jafari ◽  
Pete Smith

Heating degree days (HDD), in cases where temperatures are below 18°C, and cooling degree days (CDD), in cases where temperatures are above 21°C, were used as energy consumption indices. During the last half century, mean annual temperatures have increased, and as a consequence, CDD in the warm season have increased sharply. In the same time slice, HDD even in the cool and cold season have declined steadily. The number of monthly and annual total HDD (mean= 1556) are much higher than CDD (mean=400) in the case study area, and annual total HDD and CDD have a negative correlation (Pearson correlation = - 0.493; p = 0.001). The deceasing rate of HDD is limited and steady (R2= 0.062, p=0.099), but the increasing rate of CDD in the same time slice is sharp (R2=0.427, p=0.813). This shows that energy consumption patterns have increased sharply, and with available projection scenarios, it is projected to increase more rapidly, leading to higher energy costs.


2014 ◽  
Vol 122 (3-4) ◽  
pp. 517-529 ◽  
Author(s):  
K. P. Moustris ◽  
P. T. Nastos ◽  
A. Bartzokas ◽  
I. K. Larissi ◽  
P. T. Zacharia ◽  
...  

Author(s):  
Yuanzheng Li ◽  
Wenjing Wang ◽  
Yating Wang ◽  
Yashu Xin ◽  
Tian He ◽  
...  

The world is faced with significant climate change, rapid urbanization, massive energy consumption, and tremendous pressure to reduce greenhouse gases. Building heating and cooling is one primary source of energy consumption and anthropogenic carbon dioxide emissions. First, this review presents previous studies that estimate the specific amount of climate change impact on building heating and cooling energy consumption, using the statistical method, physical model method, comprehensive assessment model method, and the combination method of statistical and physical model methods. Then, because the heating and cooling degree days indices can simply and reliably indicate the effects of climate on building heating and cooling energy consumption, previous studies were reviewed from the aspects of heating and cooling degree days indices, regional spatial-temporal variations in degree days and related indices, influencing factors of the spatial distributions of degree days, and the impacts of urbanization on degree days. Finally, several potential key issues or research directions were presented according to the research gaps or fields that need to be studied further in the future, such as developing methods to simply and accurately estimate the specified amounts of climate change impact on building cooling and heating energy consumption; using more effective methods to analyze the daytime, nighttime, and all-day spatial-temporal changes in different seasons in the past and future under various environment contexts by considering not only the air temperature but also the relative humidity, solar radiation, population, etc., and further exploring the corresponding more kinds of driving forces, including the various remotely sensed indices, albedo, nighttime light intensity, etc.; estimating the daytime, nighttime, and all-day impacts of urbanization on heating degree days (HDDs), cooling degree days (CDDs), and their sum (HDDs + CDDs) for vast cities in different environmental contexts at the station site, city, regional and global scales; producing and sharing of the related datasets; and analyzing the subsequent effects induced by climate change on the energy consumption for building heating and cooling, etc.


Author(s):  
Khuram Pervez Amber ◽  
Muhammad Waqar Aslam ◽  
Anila Kousar ◽  
Muhammad Sajid Khan ◽  
Ghulam Qadir Chaudhary ◽  
...  

Abstract Energy usage intensity (EUI, kWh/m2/year) of a building category helps energy managers and building owners in evaluating the energy performance of their buildings. Banks are energy-intensive buildings, but there is limited research published in this highly energy-intensive building category. In this paper, the energy consumption of 98 bank buildings located in different cities of the AJK region of Pakistan has been critically analyzed and their EUI value has been established. Data were collected through site visits, interviews, and questionnaires. Electricity consumption of each bank branch was normalized using the cooling degree days method and respective annual normalized EUIs were calculated. It was found through analysis that three major factors that drive electricity consumption in bank buildings in Pakistan are building's area, the number of workstations, and the number of automatic teller machines. The EUI of banks in Pakistan has been found to be 222 kWh/m2/yr, which is comparable with the same of eight other countries.


2014 ◽  
Vol 875-877 ◽  
pp. 1812-1821
Author(s):  
Aurea Lucia Georgi Vendramin ◽  
Carlos Itsuo Yamamoto ◽  
Samuel N. Souza Melegari

The Residential sector in Brazil is responsible for 26% of energy consumption for illumination, refrigeration and heating, because of this there is a necessity to project in a correct way the openings and choose better materials for construction, targeting the energy rationalization. This article describes the development of a new model that uses a method where openings are represented by single glass and double glass. The model is based on a healthy balance equations purely theoretical and empirical data. Simplified equations are derived through a synthesis of the measured data obtained from meteorological stations, as well as the literature. The implementation of the model in a design tool integrated naturally lit buildings is discussed in this article, to better punctuate the requirements of comfort and energy efficiency in architecture and engineering. Assumes significant importance in studies of heatstroke buildings, aiming to guide the professionals through the process of architectural design, preliminary study and detail of construction elements. It was used a method of degree-days for an assessment of the energy performance of a building showed that the design of the architectural design should always be considered the materials used and the size of the openings. The energy performance was obtained through the model, considering the location of the building in the city of Curitiba, Foz do Iguaçu, Londrina and Cascavel - PR. Obtained climatic data of these locations and in a second step, it was obtained the coefficient of total heat loss in the building pre-established so evaluating the thermal comfort and energy performance. It was observed that heating degree days in winter are of 77.78 to Curitiba the base temperature of 14 ° C and cooling degree days in winter 30.17. For Curitiba lower air exchange, the lower the energy consumption for heating and thus the higher the intake, the greater exchange of air. This means that the more openings in buildings in Curitiba, and are installed to the east side, they may be higher because the glass added to the geometry of architectural spaces will cause the environment conserve energy.


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