Uncertainty in Baseline Regression Modeling and in Determination of Retrofit Savings

1998 ◽  
Vol 120 (3) ◽  
pp. 185-192 ◽  
Author(s):  
T. A. Reddy ◽  
J. K. Kissock ◽  
D. K. Ruch
Keyword(s):  
Regression Models ◽  
Energy Use ◽  
Energy Savings ◽  
Climatic Conditions ◽  
Standard Type ◽  
Operating Modes ◽  
Constant Variance ◽  
Model Residuals ◽  
Range Of Variation

The objective of this paper is to discuss the various sources of uncertainty inherent in the estimation of actual measured energy savings from baseline regression models, and to present pertinent statistical concepts and formulae to determine this uncertainty. Regression models of energy use in commercial buildings are not of the “standard” type addressed in textbooks because of the changepoint behavior of the models and the effect of patterned and non-constant variance residuals (largely as a result of changes in operating modes of the building and the HVAC system). This paper also addresses such issues as how model prediction is impacted by both improper model residuals and models identified from data periods which do not encompass the entire range of variation of both climatic conditions and the different building operating modes.

scholarly journals Estimation of Direct and Indirect Household CO2 Emissions in 49 Japanese Cities with Consideration of Regional Conditions

2020 ◽  
Vol 12 (11) ◽  
pp. 4678 ◽  
Author(s):  
Yujiro Hirano ◽  
Tomohiko Ihara ◽  
Masayuki Hara ◽  
Keita Honjo
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
Energy Use ◽  
Energy Savings ◽  
Climatic Conditions ◽  
Cold Regions ◽  
Large Cities ◽  
Direct Energy ◽  
The Relationship

We conducted a detailed estimation of direct and indirect CO2 emissions related to multi-person households in 49 Japanese cities. Direct energy consumption was decomposed into energy use in order to consider the relationship with regional conditions. The results showed that CO2 emissions from direct energy consumption were almost as large as indirect CO2 emissions induced by consuming products and services, suggesting that lifestyle improvements are important for both energy savings and reducing CO2 emissions relating to product and service consumption. In addition, CO2 emissions from direct energy consumption varied widely between cities, making them susceptible to regional conditions. We also calculated CO2 emissions from direct energy consumption and examined the regional conditions for individual forms of energy use. CO2 emissions were higher in cold regions and lower in larger cities. In Japan, large cities are often located in relatively warm areas, so we conducted an analysis to distinguish the effects of climatic conditions from those of urbanization. This analysis allowed us to clarify the effects of regional conditions on factors such as heating/cooling and the ratio of detached houses to apartments.

Benefits of Monitoring Energy Use and Production Using Enhanced Smart Meters for California Houses

2012 ◽  
Author(s):  
Sergio Escobar Vargas ◽  
Jorge E. Gonzalez ◽  
Mark Aschheim
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Cost Savings ◽  
Carbon Offsets ◽  
Smart Meters ◽  
Climatic Zones ◽  
Renewable Power ◽  
Financial Benefits ◽  
Time Determination

Methodologies have been developed to allow real-time determination of energy production and use as well as sizing of HVAC equipment based on thermal loads at the residential level. The data obtained reflect actual properties of the thermal envelope and appliance efficiencies, as well as actual renewable power production. The use of properly sized HVAC equipment introduces further energy savings. Recovery of energy savings expressed in terms of carbon offsets provides an incentive to improve the occupant’s energy footprint. When monetized, the energy cost savings and carbon offsets have financial benefits. These benefits are evaluated for model homes in various climatic zones within the state of California.

scholarly journals ANALYSIS OF RESULTS OF MEASURES PERFORMED TO INCREASE ENERGY EFFICIENCY IN VASIL KARAGIOZOV HIGH SCHOOL OF YAMBOL, BULGARIA

2018 ◽  
Vol 6 (4) ◽  
pp. 306-310 ◽  
Author(s):  
Ivan Binev
Keyword(s):  
High School ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Saving ◽  
Energy Use ◽  
Energy Savings ◽  
Climatic Conditions ◽  
Improve Energy Efficiency ◽  
Before And After ◽  
The Impact

The report analyzes the results of the implemented measures to improve energy efficiency in Vasil Karagiozov High school of Yambol, Bulgaria. Energy savings are determined by measuring and/or calculating energy consumption with previously adopted baseline levels, implementing a measure or program to improve energy efficiency by providing normalized corrections corresponding to the impact of specific climatic conditions on energy use. A reference heating energy consumption of 38.62 kWh/m2 was determined after the renovation of the building. Comparing the reference energy costs for heating before and after the implementation of the energy saving measures show a real decrease of the energy consumption for heating by 53.44%. Compared to the reference energy consumption for heating before and after the energy saving measures show an actual reduction of energy consumption for heating by 47.86%.

Multivariate Regression Modeling

1998 ◽  
Vol 120 (3) ◽  
pp. 177-184 ◽  
Author(s):  
S. Katipamula ◽  
T. A. Reddy ◽  
D. E. Claridge
Keyword(s):  
Energy Consumption ◽  
Regression Models ◽  
Energy Use ◽  
Complex Function ◽  
Climatic Conditions ◽  
Regression Modeling ◽  
Commercial Buildings ◽  
Coefficient Of Determination ◽  
Single Variable ◽  
Variable Model

An empirical or regression modeling approach is simple to develop and easy to use compared to detailed hourly simulations of energy use in commercial buildings. Therefore, regression models developed from measured energy data are becoming an increasingly popular method for determining retrofit savings or identifying operational and maintenance (O&M) problems. Because energy consumption in large commercial buildings is a complex function of climatic conditions, building characteristics, building usage, system characteristics and type of heating, ventilation, and air conditioning (HVAC) equipment used, a multiple linear regression (MLR) model provides better accuracy than a single-variable model for modeling energy consumption. Also, when hourly monitored data are available, an issue which arises is what time resolution to adopt for regression models to be most accurate. This paper addresses both these topics. This paper reviews the literature on MLR models of building energy use, describes the methodology to develop MLR models, and highlights the usefulness of MLR models as baseline models and in detecting deviations in energy consumption resulting from major operational changes. The paper first develops the functional basis of cooling energy use for two commonly used HVAC systems: dual-duct constant volume (DDCV) and dual-duct variable air volume (DDVAV). Using these functional forms, the cooling energy consumption in five large commercial buildings located in central Texas were modeled at monthly, daily, hourly, and hour-of-day (HOD) time scales. Compared to the single-variable model (two-parameter model with outdoor dry-bulb as the only variable), MLR models showed a decrease in coefficient of variation (CV) between 10 percent to 60 percent, with an average decrease of about 33 percent, thus clearly indicating the superiority of MLR models. Although the models at the monthly time scale had higher coefficient of determination (R2) and lower CV than daily, hourly, and HOD models, the daily and HOD models proved more accurate at predicting cooling energy use.

Toplotno bilansiranje i povećanje efikasnosti korišćenja toplotne energije vrtića „Zeka“ u gradu Kragujevcu, Srbija

2020 ◽  
Vol 22 (1-2) ◽  
pp. 119-125
Author(s):  
Davor Jovanović ◽  
◽  
Dušan Gordić ◽  
Jelena Nikolić ◽  
Nebojša Jurišević ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Thermal Energy ◽  
Energy Use ◽  
Energy Savings ◽  
Heating System ◽  
Transfer Coefficients ◽  
Climate Conditions ◽  
Heat Transfer Coefficients ◽  
Energy Conservation Measures

This paper shows the thermal energy audit of the kindergarten "Zeka", located in the territory of the city of Kragujevac, Serbia. Data of the analyzed building, with an emphasis on the heating system, as well as the climate conditions of the location are shown. Analysis of the thermal energy use, done by implementing a software package "URSA-građevinska fizika 2", shows that the analyzed building belongs to the "G" energy efficiency level, which indicates that the heat transfer coefficients are not in the range defined by the Rule book of energy efficiency for buildings. Consequently, the energy conservation measures for increasing the efficiency of thermal energy use are proposed. Besides, for each measure, the techno- economic analysis was done, which includes determination of the investment costs, as well as the payback period. By implementing the appropriate measures in the analyzed building, it was concluded that thermal energy savings of almost 79% can be achieved.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

Adaptive changes of the hair coat of the horses of zabaykalsky aborigenous breed

2019 ◽  
Vol 49 (4) ◽  
pp. 101-105 ◽  
Author(s):  
G. M. Shkyratova ◽  
B. Z. Bazaron ◽  
T. N. Khamiruev ◽  
S. M. Dashinimaev
Keyword(s):  
Seasonal Changes ◽  
Climatic Conditions ◽  
Skin Thickness ◽  
Summer Period ◽  
Hair Coat ◽  
Skin Fold ◽  
Winter Grazing ◽  
Shoulder Blade ◽  
Quantitative Indicators

The seasonal changes in the skin thickness and structure of the horses’ coat, as signs of adaptation to environmental factors, were studied. The experiment was carried out with the livestock kept in a herd using winter-grazing technology without additional feedings in the climatic conditions of the Trans-Baikal Territory. The objects of the research were adult mares of Zabaikalsky breed of horses of the same age, class and fatness. The studies were carried out in the middle of each season (May, July, October, February). The length of the coat was measured with a caliper, the coat itself with the determination of the ratio of hair (fl uffy hair, heterotype hair and coarse hair) and the thickness of the skin fold were measured in accordance with the approved methodological recommendations. The minimum skin thickness in winter was detected in mares on the back and shoulder blade – 4.3 and 4.4 mm, the maximum – on the side and thigh – 4.5 4.6 mm. When compared with the summer period, the increase on the side was 0.8 mm, whereas on the back, shoulder blade and thigh – 0.4 mm (p ≤ 0,001). In spring, thickening of the skin was noted within 0.1-0.3 mm in the same topographic areas, compared to autumn. The quantitative indicators of the coat changed depending on the season of the year. In winter, the coat contained more fl uffy hair (23.10%), and less coarse hair (68.24%), in summer there was a lower content of fl uffy hair (4.33%), but more coarse hair (94.01%.) Sharp seasonal changes were noted with regard to the length of the hair. The longest hair was found in winter and spring – 4.96 and 4.26 cm, whereas the shortest – in summer and autumn – 0.94 and 1.90 cm, respectively.

scholarly journals Review of Intelligent Control Systems for Natural Ventilation as Passive Cooling Strategy for UK Buildings and Similar Climatic Conditions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4388
Author(s):  
Esmail Mahmoudi Saber ◽  
Issa Chaer ◽  
Aaron Gillich ◽  
Bukola Grace Ekpeti
Keyword(s):  
Control Systems ◽  
Natural Ventilation ◽  
Energy Use ◽  
Integrated Control ◽  
Climatic Conditions ◽  
Effective Control ◽  
Practical Implementation ◽  
Optimal Output ◽  
Heating And Cooling ◽  
Building Cooling

Natural ventilation is gaining more attention from architects and engineers as an alternative way of cooling and ventilating indoor spaces. Based on building types, it could save between 13 and 40% of the building cooling energy use. However, this needs to be implemented and operated with a well-designed and integrated control system to avoid triggering discomfort for occupants. This paper seeks to review, discuss, and contribute to existing knowledge on the application of control systems and optimisation theories of naturally ventilated buildings to produce the best performance. The study finally presents an outstanding theoretical context and practical implementation for researchers seeking to explore the use of intelligent controls for optimal output in the pursuit to help solve intricate control problems in the building industry and suggests advanced control systems such as fuzzy logic control as an effective control strategy for an integrated control of ventilation, heating and cooling systems.

scholarly journals Energy and Greenhouse Gas Savings for LEED-Certified U.S. Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 749
Author(s):  
John H. Scofield ◽  
Susannah Brodnitz ◽  
Jakob Cornell ◽  
Tian Liang ◽  
Thomas Scofield
Keyword(s):  
Greenhouse Gas ◽  
Energy Use ◽  
Energy Savings ◽  
Electric Energy ◽  
Building Energy ◽  
Energy Performance ◽  
Office Buildings ◽  
Ghg Emission ◽  
Site Energy ◽  
New Construction

In this work, we present results from the largest study of measured, whole-building energy performance for commercial LEED-certified buildings, using 2016 energy use data that were obtained for 4417 commercial office buildings (114 million m2) from municipal energy benchmarking disclosures for 10 major U.S. cities. The properties included 551 buildings (31 million m2) that we identified as LEED-certified. Annual energy use and greenhouse gas (GHG) emission were compared between LEED and non-LEED offices on a city-by-city basis and in aggregate. In aggregate, LEED offices demonstrated 11% site energy savings but only 7% savings in source energy and GHG emission. LEED offices saved 26% in non-electric energy but demonstrated no significant savings in electric energy. LEED savings in GHG and source energy increased to 10% when compared with newer, non-LEED offices. We also compared the measured energy savings for individual buildings with their projected savings, as determined by LEED points awarded for energy optimization. This analysis uncovered minimal correlation, i.e., an R2 < 1% for New Construction (NC) and Core and Shell (CS), and 8% for Existing Euildings (EB). The total measured site energy savings for LEED-NC and LEED-CS was 11% lower than projected while the total measured source energy savings for LEED-EB was 81% lower than projected. Only LEED offices certified at the gold level demonstrated statistically significant savings in source energy and greenhouse gas emissions as compared with non-LEED offices.

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