Annual and Monthly Trends of Cooling and Heating Degree-Days in Four Different Cities in Iraq as an Index of Energy Consumption

2021 ◽  
Author(s):  
Khamis Daham Muslih
Keyword(s):  
Energy Consumption ◽  
Degree Days ◽  
Heating Degree Days

Climate Change as a Driving Force on Urban Energy Consumption Patterns

2018 ◽  
pp. 7815-7830
Author(s):  
Mostafa Jafari ◽  
Pete Smith
Keyword(s):  
Energy Consumption ◽  
Pearson Correlation ◽  
Consumption Patterns ◽  
Time Slice ◽  
Degree Days ◽  
Urban Energy ◽  
Cooling Degree Days ◽  
Energy Consumption Patterns ◽  
Annual Total ◽  
Heating Degree Days

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.

Revised heating degree days due to global warming for 15 major cities of South Korea

2011 ◽  
Vol 32 (4) ◽  
pp. 377-383 ◽  
Author(s):  
Sung-Hwan Cho ◽  
Hyeong-Jung Kim ◽  
M Zaheeruddin
Keyword(s):  
Global Warming ◽  
Energy Consumption ◽  
South Korea ◽  
Degree Days ◽  
Practical Applications ◽  
Ambient Temperatures ◽  
Temperature Levels ◽  
Heating Degree Days ◽  
Equipment Size ◽  
The Impact

Because of the rapid rise in ambient temperatures in urban cities due to global warming, this research study was conducted to revise the heating degree days (HDDs) for main cities of South Korea. Current HDDs used in the design of heating systems were established some 30 years ago. Therefore, there is a need to revisit and revise the HDDs used in Korea. The HDDs were computed at five different indoor set-point and unloaded temperatures. The validity of the methodology used for computing HDDs was ascertained by comparing the calculated HDDs with the published values. The impact of the length of time on total annual HDDs was examined. The results show that higher temperature trends due to global warming witnessed over the past decade in general decreased the HDDs. The impact was higher for warmer climate cities than the cold regions. The revised annual HDDs for 15 major cities of South Korea are presented in this paper. Practical applications: The HDDs corrected for global warming effects for 15 major cities of South Korea presented in this article are useful for designers in estimating the impact on equipment size and energy consumption. Towards this end, several scenarios of global warming effects are presented by assuming several unloaded temperature levels. This is useful for the designers in examining the uncertainties in the estimation of energy consumption. The results published are also important for policy makers in South Korea to examine the need for revising the degree day database in light of the global warming trends.

A method to estimate the heating and cooling degree-days for different climatic zones of Saudi Arabia

2016 ◽  
Vol 38 (3) ◽  
pp. 327-350 ◽  
Author(s):  
Madhavi Indraganti ◽  
Djamel Boussaa
Keyword(s):  
Saudi Arabia ◽  
Energy Consumption ◽  
Regression Models ◽  
Outdoor Environment ◽  
Base Temperature ◽  
Degree Days ◽  
Climatic Zones ◽  
Heating And Cooling ◽  
Cooling Degree Days ◽  
Heating Degree Days

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%.

Climate Change as a Driving Force on Urban Energy Consumption Patterns

2019 ◽  
pp. 547-563
Author(s):  
Mostafa Jafari ◽  
Pete Smith
Keyword(s):  
Energy Consumption ◽  
Pearson Correlation ◽  
Consumption Patterns ◽  
Time Slice ◽  
Degree Days ◽  
Urban Energy ◽  
Cooling Degree Days ◽  
Energy Consumption Patterns ◽  
Annual Total ◽  
Heating Degree Days

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.

Heating degree-days over Greece as an index of energy consumption

2004 ◽  
Vol 24 (14) ◽  
pp. 1817-1828 ◽  
Author(s):  
Andreas Matzarakis ◽  
Christos Balafoutis
Keyword(s):  
Energy Consumption ◽  
Degree Days ◽  
Heating Degree Days

Heating degree–days for arid regions

Energy ◽  
1998 ◽  
Vol 23 (12) ◽  
pp. 1089-1094 ◽  
Author(s):  
Zekai Şen ◽  
Mikdat Kadiogl̂u
Keyword(s):  
Arid Regions ◽  
Degree Days ◽  
Heating Degree Days

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

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