scholarly journals Predicting the Effects of Changes in Thermal Envelope Characteristics on Energy Consumption: Application and Verification of a Simple Model for Australian and Canadian Climates

1996 ◽  
Vol 7 (1) ◽  
pp. 1-28
Author(s):  
S. M. Cornick ◽  
P.C. Thomas ◽  
D.K. Prasad
Keyword(s):  
Cooling System ◽  
Thermal Characteristics ◽  
Building Envelope ◽  
Hvac System ◽  
Paper Briefly ◽  
Heating And Cooling ◽  
Wide Range ◽  
Similarities And Differences ◽  
System Configurations ◽  
New Buildings

A simple energy model was used for determining thermal envelope characteristics and building envelope trade-off procedures for the new Canadian and Australian energy efficiency codes for new buildings. The model relates heating and cooling system loads to envelope thermal characteristics. It was developed from thousands of DOE2.1E simulation runs. Two separate databases, one containing 25 Canadian locations and the other containing 9 Australian locations were created. The heating and cooling models were developed from these databases. The model is shown to give consistent results although there are significant differences in climate, construction of the building envelope, building operational schedules and HVAC system configurations. This paper briefly describes the DOE2.1E models used for the study in each country, highlighting similarities and differences. The consistency of results predicted by the model is discussed for typical climatic locations in both countries. The methods for predicting heating and cooling system loads are shown to produce good results over a wide range of climates and for different system configurations. The paper also discusses the development of climate correlations to extend the range of the models to include locations not in the original databases.

scholarly journals Numerical Evaluation of a HVAC System Based on a High-Performance Heat Transfer Fluid

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Cooling System ◽  
Electrical Energy ◽  
Simulation Software ◽  
Heat Transfer Fluid ◽  
Hvac System ◽  
Dynamic Simulations ◽  
Heating And Cooling ◽  
The University

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

scholarly journals WattScale

2021 ◽  
Vol 2 (1) ◽  
pp. 1-25
Author(s):  
Srinivasan Iyengar ◽  
Stephen Lee ◽  
David Irwin ◽  
Prashant Shenoy ◽  
Benjamin Weil
Keyword(s):  
Cooling System ◽  
Large Population ◽  
Ground Truth ◽  
Detection Algorithm ◽  
Building Envelope ◽  
Ground Truth Data ◽  
Heating And Cooling ◽  
Data Driven Approach ◽  
Execution Mode ◽  
The Individual

Buildings consume over 40% of the total energy in modern societies, and improving their energy efficiency can significantly reduce our energy footprint. In this article, we present WattScale, a data-driven approach to identify the least energy-efficient buildings from a large population of buildings in a city or a region. Unlike previous methods such as least-squares that use point estimates, WattScale uses Bayesian inference to capture the stochasticity in the daily energy usage by estimating the distribution of parameters that affect a building. Further, it compares them with similar homes in a given population. WattScale also incorporates a fault detection algorithm to identify the underlying causes of energy inefficiency. We validate our approach using ground truth data from different geographical locations, which showcases its applicability in various settings. WattScale has two execution modes—(i) individual and (ii) region-based, which we highlight using two case studies. For the individual execution mode, we present results from a city containing >10,000 buildings and show that more than half of the buildings are inefficient in one way or another indicating a significant potential from energy improvement measures. Additionally, we provide probable cause of inefficiency and find that 41%, 23.73%, and 0.51% homes have poor building envelope, heating, and cooling system faults, respectively. For the region-based execution mode, we show that WattScale can be extended to millions of homes in the U.S. due to the recent availability of representative energy datasets.

scholarly journals The Profitability Analysis Of Enhancement Of Parameters Of The Thermal Insulation Of Building Partitions

2014 ◽  
Vol 60 (3) ◽  
pp. 335-347
Author(s):  
A. Życzyńska ◽  
T. Cholewa
Keyword(s):  
Thermal Insulation ◽  
Energy Savings ◽  
Cooling System ◽  
Residential Buildings ◽  
Building Envelope ◽  
Existing Buildings ◽  
Profitability Analysis ◽  
Payback Time ◽  
Technical Solutions ◽  
New Buildings

Abstract The energy saving tendencies, in reference to residential buildings, can be recently seen in Europe and in the world. Therefore, there are a lot of studies being conducted aiming to find technical solutions in order to improve the energy efficiency of existing, modernized, and also new buildings. However, there are obligatory solutions and requirements, which must be implemented during designing stage of the building envelope and its heating/cooling system. They are gathered in the national regulations. The paper describes the process of raising the energy standard of buildings between 1974–2021 in Poland. Therefore, the objective of this study is to show energy savings, which can be generated by modernization of thermal insulation of partitions of existing buildings and by the use of different ways of heat supply. The calculations are made on the selected multi-family buildings located in Poland, with the assumption of a 15 years payback time. It is shown that it is not possible to cover the costs of the modernization works by the projected savings with the compliance to the assumption of 15 years payback time.

scholarly journals Energy Monitoring in a Heating and Cooling System in a Building Based on the Example of the Turówka Hotel

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1968 ◽  
Author(s):  
Marek Borowski ◽  
Piotr Mazur ◽  
Sławosz Kleszcz ◽  
Klaudia Zwolińska
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Energy Demand ◽  
Cooling System ◽  
Energy Performance ◽  
High Energy ◽  
Building Envelope ◽  
Large Variability ◽  
Heating And Cooling ◽  
And Control

The energy consumption of buildings is very important for both economic and environmental reasons. Newly built buildings are characterized by higher insulation and airtightness of the building envelope, and are additionally equipped with technologies that minimize energy consumption in order to meet legal requirements. In existing buildings, the modernization process should be properly planned, taking into account available technologies and implementation possibilities. Hotel buildings are characterized by a large variability of energy demand, both on a daily and a yearly basis. Monitoring systems, therefore, provide the necessary information needed for proper energy management in the building. This article presents an energy analysis of the Turówka hotel located in Wieliczka (southern Poland). The historical hotel facility is being modernized as part of the project to adapt the building to the requirements of a sustainable building. The modernization proposal includes a trigeneration system with a multifunctional reverse regenerator and control module using neural algorithms. The main purpose is to improve the energy efficiency of the building and adapt it to the requirements of low-energy buildings. The implementation of a monitoring system enables energy consumption to be reduced and improves the energy performance of the building, especially through using energy management systems and control modules. The proposed retrofit solution considers the high energy consumption, structure of the energy demand, and limits of retrofit intervention on façades.

scholarly journals Energy performance modelling and heat recovery unit efficiency assessment of an office building

2015 ◽  
Vol 19 (3) ◽  
pp. 865-880 ◽  
Author(s):  
Norbert Harmati ◽  
Radomir Folic ◽  
Zoltán Magyar
Keyword(s):  
Energy Demand ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Building ◽  
Hvac System ◽  
Analysis Model ◽  
Case Scenario ◽  
Performance Modelling ◽  
Heating And Cooling ◽  
Simulation Engine

This paper investigates and analyzes a typical multi-zone office building?s annual energy performance for the location and climate data of central Belgrade. The aim is to evaluate the HVAC system?s and HR unit?s performance in order to conduct the most preferable heating and cooling solution for the typical climate of Belgrade city. The energy performance of four HVAC system types (heat pump - air to air, gas-electricity, electrical and fan coil system) was analyzed, compared and evaluated on a virtual office building model in order to assess the total annual energy performance and to determine the efficiency of the HR unit?s application. Further, the parameters of an energy efficient building envelope, HVAC system, internal loads, building operation schedules and occupancy intervals were implemented into the multi-zone analysis model. The investigation was conducted in EnergyPlus simulation engine using system thermodynamic algorithms and surface/air heat balance modules. The comparison and evaluation of the obtained results was achieved through the conversion of the calculated total energy demand into primary energy. The goal is conduct the most preferable heating and cooling solution (Best Case Scenario) for the climate of Belgrade city and outline major criteria in qualitative enhancement.

Comprehensive Analysis and Research on the Factors Influencing Energy Efficiency and Consumption of Public Buildings

2013 ◽  
Vol 848 ◽  
pp. 155-160 ◽  
Author(s):  
Yu Zhang ◽  
Lei Zhang
Keyword(s):  
Energy Efficiency ◽  
Natural Ventilation ◽  
Building Envelope ◽  
Design Parameters ◽  
Hvac System ◽  
Total Energy Consumption ◽  
Natural Lighting ◽  
Coupling Relationship ◽  
Heating And Cooling ◽  
Relationship Of

A public building of Jiangsu Province is analyzed by DeST software based on the coupling relationship of building envelope, natural ventilation, lighting and natural lighting, and HVAC system, and the annual heating and cooling loads and power consumption of design building and benchmark building are calculated. After fully taking into account coupling relationship of all factors, a reasonable choice of design parameters, the design of HVAC system is optimized, achieving the goal that total energy consumption of design building is less than 80% of specified value of energy efficiency by national and local standards.

scholarly journals Correlation of Ventilative Cooling Potentials and Building Energy Savings in Various Climatic Zones

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 968 ◽  
Author(s):  
Haolia Rahman ◽  
Hwataik Han
Keyword(s):  
Energy Savings ◽  
Cooling System ◽  
Thermal Characteristics ◽  
Temperature Shift ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Climatic Zones ◽  
Adaptive Thermal Comfort ◽  
Temperature Ranges ◽  
Computer Based

The introduction of cool outdoor air can help in reducing the energy consumption for cooling during summer. Ventilative cooling potentials (VCPs) have been defined in various ways in the literature to represent potential cooling hours in specified outdoor temperature ranges. However, the energy-saving potential of ventilative cooling can differ between buildings in the same climatic zone depending on the buildings’ thermal characteristics and system operations. In this study, new VCPs are introduced with an index of temperature shift based on adaptive thermal comfort. This index can be determined based on the balance temperature difference of the buildings, which is defined as the heat gain in the building divided by the thermal transmission and air exchange characteristics of the building envelope under quasi-steady state conditions. The proposed method was also compared with those reported in the literature, including a computer-based VCP tool. It is the objective of the present study to investigate the correlation between VCPs and actual energy savings via ventilative cooling. Simulations were conducted in an office building for a four-month period during summer to calculate the energy saved via ventilative cooling in comparison with that achieved with a mechanical cooling system. Eight cities representing four different climatic conditions were considered: tropical, dry, temperate, and continental. Our results revealed a strong correlation between the energy savings and the proposed VCPs in the case of a proper temperature shift estimation in all climatic zones. The computerized VCP tool also exhibited good correlation with the calculated energy savings and with the VCPs proposed herein.

Thermal performance of a radiant wall heating and cooling system with pipes attached to thermally insulating bricks

2021 ◽  
pp. 111122
Author(s):  
Michal Krajčík ◽  
Martin Šimko ◽  
Ondřej Šikula ◽  
Daniel Szabó ◽  
Dušan Petráš
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Heating And Cooling ◽  
Wall Heating

Thermal analysis method of electromagnetic linear actuator based on multiphysics coupling model

2021 ◽  
pp. 1-17
Author(s):  
Geng Wang ◽  
Renjing Gao ◽  
Qi Wang ◽  
Shutian Liu
Keyword(s):  
Thermal Analysis ◽  
Thermal Characteristics ◽  
Coupling Model ◽  
Analysis Method ◽  
Thermal Analysis Method ◽  
Performance Requirements ◽  
Wide Range ◽  
Multiphysics Coupling ◽  
Simulation And Experiment ◽  
Electromagnetic Linear Actuator

Electromagnetic linear actuators (ELAs) may be confronted with unsatisfactory performance when subjected to overheating. Therefore, it is significant to clarify its thermal characteristics and design the thermal performance requirements. A thermal analysis method based on multiphysics coupling model was presented, which uses the non-simplified loss distribution as the heat source to calculate the temperature field, adjusts the material properties by temperature, and considers the interaction between motion (including impact) and loss. More importantly, an improved universal equivalent winding to satisfy the condition of real compact concentrated winding was developed. Finally, the validity of this approach was verified through the experiment, and the regularity of temperature was summarized. The results show that the error of simulation and experiment is less than 6% and the permissible continuous operation frequency is no more than 30 Hz. The approach proposed in this paper can be employed not only to the ELA, but also to the design and analysis a wide range of electromagnetic machines.

scholarly journals Design and thermal characteristic analysis of motorized spindle cooling system

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110208
Author(s):  
Yuan Zhang ◽  
Lifeng Wang ◽  
Yaodong Zhang ◽  
Yongde Zhang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Thermal Deformation ◽  
Cooling System ◽  
Thermal Characteristic ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Characteristic Analysis ◽  
Motorized Spindle ◽  
Experiment And Simulation

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.

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