Residential Energy Analysis: Regression Analysis of Heating Degree Days With Temperature Setback for Selected ASHRAE Climate Zones

2011 ◽  
Author(s):  
Patrick A. Kearns ◽  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Simulation Analysis ◽  
Residential Buildings ◽  
Base Temperature ◽  
Degree Days ◽  
Climate Zones ◽  
Detailed Simulation ◽  
Input Variables ◽  
Heating Degree Days ◽  
The Impact

Heating Degree Days (HDDs), calculated from hourly weather data, are often used to estimate energy savings for a variety of energy efficiency measures (EEMs) to be applied to conditioned spaces in buildings. More specifically, application of HDDs is useful for estimating savings from weather-dependent EEMs. For first order estimation, it is often problematic to calculate HDDs for a given base temperature, when temperature setbacks are used in the conditioned spaces. This paper provides a set of correlations to characterize HDDs for selected ASHRAE Climate Zones as functions of three key parameters including the base temperature, setback temperature level (delta-T), and setback duration. In addition to the well-documented pattern of decreasing HDDs for decreasing base temperature, it was also shown that HDDs are inversely proportional to both setback duration and temperature setback differential levels. In the analysis presented in this paper, corrections to estimate HDDs when temperature setbacks are used for typical residential space heating schedules during unoccupied periods which occurred from 8 am to 5 pm Monday through Friday. In particular, regression correlations using two- and three-parameter models have been developed to estimate HDDs for multiple US locations that account for the impact of temperature setbacks on the heating requirements of residential buildings. For the two-parameter model, the input variables for the regression correlations are setback hours and delta T; for the three-parameter model, the input variables for the correlations include setback hours, delta T, and base temperature. The prediction accuracy for the energy savings, due to a set of EEMs, obtained from the HDD method —using the developed correlations— is tested against whole-building detailed energy simulation analysis for two single family homes. Detailed energy audits including utility data analysis have been carried out for both homes to calibrate the detailed simulation model and evaluate the effectiveness of the EEMs in reducing building energy use. The results from the detailed simulation analysis are then compared to those obtained from the HDD with temperature setbacks.

Roof Cover Impact on Cooling Energy Use of Office Buildings

2014 ◽  
Author(s):  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Calculation Model ◽  
Office Building ◽  
Climate Zones ◽  
Building Energy Use ◽  
Detailed Simulation ◽  
Simplified Calculation ◽  
The Impact

This paper analyzes the impact of roof covers on office building energy use for representative US climate zones. In particular, the study presented in the paper investigates the potential annual cooling energy use savings that roof covers could provide using whole-building simulation analysis to evaluate the performance of a 2-story office building in five US locations. Three parameters of the roof covers including their size, height, and transmittance, are considered in the analysis. The simulation results indicate that while roof covers had similar affects on buildings in all climate zones, their impact in reducing cooling energy usage is different and is more pronounced in cooler climates. Specifically, roof covers could potentially achieve cooling energy savings of up to: 25% in Houston, 33% in Atlanta, 31% in Nashville, 38% in Chicago, and 41% in Madison. Based on the detailed simulation analysis results, a simplified calculation model is developed to help the estimation of cooling energy savings as a function of the roof cover size, height, and transmittance.

scholarly journals Energy Saving Potential from Shading Design for Residential House in Rural Area

2018 ◽  
Vol 164 ◽  
pp. 01007
Author(s):  
Dany Perwita Sari ◽  
Yun-shang Chiou
Keyword(s):  
Energy Saving ◽  
Rural Area ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Residential Buildings ◽  
Substantial Impact ◽  
Energy Saving Potential ◽  
Key Factor ◽  
Residential House ◽  
Shading Devices

There are some architectural factors in the energy saving design of residential houses in Taiwan. In addition, in rural area, window glazing is a key factor to reducing electricity. For these purposes, a simulation model of exterior shading has been done in this study. Various types of shading devices have been analysed and compared in terms of energy savings. Simulation analysis by DesignBuilder reveals that shading devices has substantial impact to minimizing energy consumption. The results derived in this paper could provide useful suggestions for the shading design of residential buildings at rural area in Taiwan.

Analysis of Daylighting Benefits for Office Buildings in Egypt

Solar Energy ◽  
2004 ◽  
Author(s):  
Mostafa Abd El Mohimen ◽  
George Hanna ◽  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Simulation Analysis ◽  
Window Size ◽  
Electrical Energy ◽  
Office Buildings ◽  
Wall Area ◽  
Electricity Use ◽  
Daylighting Control ◽  
The Impact ◽  
Geographical Locations

This paper summarizes the results of a simulation analysis to determine the effectiveness of daylighting in reducing electrical energy consumption for office buildings in Egypt. Specifically, the impact on daylighting performance is investigated of window size, building size, daylighting control, and glazing type for three geographical locations in Egypt. It was determined that a window to wall area ratio of 0.20 minimizes the total annual electricity use for office buildings in three Egyptian locations, Cairo, Alexandria, and Aswan. A simplified analysis method is developed based on the analysis results to estimate the annual electrical energy savings attributed to daylighting.

Analysis of Electrical Energy Savings From Daylighting Through Skylights

Solar Energy ◽  
2005 ◽  
Author(s):  
Abdelkarim Nemri ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Control Strategies ◽  
Electrical Energy ◽  
Office Building ◽  
Analysis Tool ◽  
Energy Saving Potential ◽  
Lighting Energy ◽  
The Impact

This paper provides a simplified analysis tool to assess the energy saving potential of daylighting for commercial buildings through skylights. Specifically, the impact of daylighting is investigated for various fenestration opening sizes, glazing types, control strategies, and geographic locations. A top floor of a prototypical office building has been considered in the analysis. The results obtained for the office building can be applied to other types of buildings such as retails stores, schools, and warehouses. Based on the simulation analysis results, it was determined that skylight to floor ratio more than 0.3 does not affect significantly the lighting energy savings. An optimum value of skylight to floor area ratio was found to be 0.2 to minimize the annual total building energy use.

scholarly journals Impact of Wall Constructions on Energy Performance of Switchable Insulation Systems

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6068
Author(s):  
Remy Carlier ◽  
Mohammad Dabbagh ◽  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Simulation Analysis ◽  
Residential Buildings ◽  
Energy Performance ◽  
Space Heating ◽  
Thermal Mass ◽  
Analysis Tool ◽  
Insulation Systems ◽  
Detached House ◽  
Modeling Strategy

This paper evaluates the potential energy savings when switchable insulation systems (SIS) are applied to walls of residential buildings located in Belgium and other locations in Europe. The study considers two low-energy prototypical dwellings (an apartment and a detached house) that are representative of post-2010 constructions and renovations in Belgium. Using an 3R2C-based analysis tool, the performance of both dwellings is evaluated with static and dynamic wall insulation systems. First, the switchable insulating system is described along with its associated simple 2-step rule-based control strategy. Then the modeling strategy and simulation analysis tools are presented. In Belgium, it was found that SIS-integrated walls allow energy savings up to 3.7% for space heating and up to 98% for cooling. Moreover, it was found that to further reduce the energy consumption of SIS-integrated buildings in various European climates, thermal mass placement needs to be considered. By optimizing the placement and the parameters of the various wall layers, it is possible to increase the space heating savings by up to a factor of 4 and those of cooling by up to a factor of 2.5.

The Estimation of Base Temperature for Heating and Cooling Degree-Days for South Korea

2014 ◽  
Vol 53 (2) ◽  
pp. 300-309 ◽  
Author(s):  
Kyoungmi Lee ◽  
Hee-Jeong Baek ◽  
ChunHo Cho
Keyword(s):  
Climate Change ◽  
South Korea ◽  
Piecewise Linear ◽  
Regional Scale ◽  
Electricity Demand ◽  
Linear Regression Method ◽  
Base Temperature ◽  
Degree Days ◽  
Cooling Degree Days ◽  
The Impact

AbstractIn South Korea, heating degree-days (HDD) and cooling degree-days (CDD) have been widely used as climatic indicators for the assessment of the impact of climate change, but arbitrary or customary base temperatures have been used for calculation of HDD and CDD. The purpose of this study is to determine real base temperatures to accurately calculate HDD and CDD for South Korea, using monthly electric energy consumption and mean temperature data from 2001 to 2010. The results reveal that the regional electricity demand generally depends on air temperature in a V-shaped curve in urban settings but in an L-shaped curve in rural settings, indicating that the sensitivity of the electricity demand to the temperature change is affected by the size of cities. The South Korean regional base temperatures, defined by a piecewise linear regression method, range from 14.7° to 19.4°C. These results suggest that the assessment of climate change impacts on the energy sector in South Korea should be carried out on a regional scale.

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%.

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