Energy Efficient Room Research Articles

Developing a transition-metal-free green protocol for the electrophilic hydrazination of silyl enol ethers using diazo electrophiles with EtOH–H2O as a safe solvent

We report a metal catalyst-free, HF-free and open-flask green protocol for the electrophilic hydrazination of enoxy silanes at an energy-efficient room temperature, taking advantage of the eco-safe EtOH–H2O solvent.

AN ENGINEERING DESIGN PROJECT TO PROVIDE MULTI-DISCIPLINARY EXPERIENTIAL LEARNING

First year engineering students at the University of British Columbia Okanagan, take the Fundamentals of Sustainable Engineering Design course as part of the suite of common courses for all engineering students regardless of discipline. The largest assessment components of the course are the final exam (40%) and the design project (40%). 
 For the design project, teams of 4 – 6 students build a scaled-down prototype of a Well Ventilated yet Energy Efficient Room (WeVeyEER) that must be able to maintain its interior temperature at 10°C above ambient and at the same time continuously exchange stale air from within with fresh air from outside. It also has to meet load-bearing, size and power supply constraints. The energy consumption, rate of air exchange and weight are parameters for comparing performance of the prototypes.
 The majority of teams (55 out of 64) could achieve the requirements. Feedback about the project was mixed, with 57 positive and 56 negative comments.

Oriented synthesis of Co3O4 core-shell microspheres for high-performance asymmetric supercapacitor

Herein, Co3O4 core-shell microspheres are successfully designed and synthesized via a new rapid and energy-efficient room temperature interfacial-reaction and applied to supercapacitors for the first time. Morphological characterizations of the Co3O4 core-shell microspheres are carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), showing their microsphere shape with diameter approximately 1 μm. The unique structure not only provides abundant active sites but facilitates ions and electrons transitive process. As a consequence, the intriguing structural advantages endow Co3O4 core-shell microspheres with outstanding electrochemical performances: 261.1 F/g at a current density of 0.5 A/g; excellent cycle stability of 90.2% capacity retention over continuous 2000 cycles. When being paired with active carbon (AC), the resulting asymmetrical supercapacitor manifests a high energy density of 16.6 Wh/kg at a power density of 883 W/kg. Overall, this oriented approach provides a new and facile idea to fabricate core-shell or hollow-out structure as high-performance electrode for supercapacitors.

Energy efficient room temperature synthesis of cardanol-based novolac resin using acoustic cavitation

The present study deals with synthesis of cardanol-cased novolac (CBN) resin by the condensation reaction between cardanol and formaldehyde using acoustic cavitation. It is a step-growth polymerization which occurs in the presence of an acid catalyst such as adipic acid, citric acid, oxalic acid, sulphuric acid and hydrochloric acid. CBN was also synthesised by a conventional method for the sake of comparison of techniques. The effect of molar ratio, effect of catalyst, effect of different catalyst and effect of power on the conversion to CBN has been studied. The synthesised CBN was characterized using the Fourier Transform Infra Red Spectroscopy (FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance (NMR) Spectroscopy and Thermogravimetric Analysis (TGA). The reaction was monitored by the Acid value, free formaldehyde content and viscosity of the synthesised product. The reaction time required for the conventionally synthesised CBN was 5 h (300 min) with 120 °C as an operating temperature while sonochemically the time reduced to 30 min at room temperature. The amount of time and energy saved can be quantified. Ultrasound facilitated synthesis was found to be an energy efficient and time-saving method for the synthesis of novolac resin.

Synthesis of hollow and hollowed-out Co3O4 microspheres assembled by porous ultrathin nanosheets for ethanol gas sensors: Responding and recovering in one second

In this work, the hollow and hollowed-out Co3O4 microspheres (Co3O4-HHMSs) assembled by porous ultrathin nanosheets with thickness of about 3nm were synthesized via a new rapid and energy-efficient room temperature interfacial-reaction. The structure and morphology of the as-prepared products were characterized by various methods As expected, the gas sensor based on Co3O4-HHMSs exhibits high response and ultra-fast response/recovery speed when detecting ethanol. Especially, in our knowledge, both of the response and recovery time in 1s at the same time for one metal-oxide (MOX) semiconductor film gas sensor was the first time reported up to now. The formation mechanism of Co3O4-HHMSs and the gas sensing mechanism of high response and the ultra-fast response/recovery speed of the sensor are discussed in detail. Notably, the hollow and hollowed-out nanostructure assembled by porous ultrathin nanosheets with thickness of about 3nm is mainly responsible for the high response and ultra-fast response/recovery speed of the sensor.

Drivers of moderate increase in cooling energy use in residential buildings in Hong Kong

Increase in cooling energy usage of the residential sector in Hong Kong has been moderate in the most recent ten years (2004–2013). Factors and drivers responsible for this are of interest to policy makers in search of performance improvement but such information is not available in extant literature. This paper reviews the policy instruments introduced in Hong Kong during this period of time and examines the different engineering factors contributing to improvements in cooling energy efficiency. Whether the policy instruments have been instrumental in bringing about changes in engineering design and thus improvement in cooling energy efficiency is evaluated on the basis of the equipment and building envelope characteristics of 64 residential developments in Hong Kong. Different statistical analyses reveal that the use of more energy efficient room air-conditioning units (COP), smaller window-to-wall ratios (WWR) and walls with higher U-values are the engineering factors (WallU) that have contributed to moderation of growth of energy consumption; these were driven by policies introduced by the Hong Kong Government. Regarding the sensitivity of the three engineering factors, it was found that COP was the highest amounting to 0.455, followed in descending order by WallU and WWR. Their sensitivities were 0.289 and 0.006, respectively.

Information inefficiency and willingness-to-pay for energy-efficient technology: A stated preference approach for China Energy Label

The paper examines the extent to which consumers' willingness-to-pay for energy-efficient room air conditioners may be altered by correcting the information inefficiency on the China Energy Label. The data are collected from a discrete choice experiment with two alternatives (variable-speed and constant-speed room air conditioners) characterized by attributes of brand, purchase price and energy grade. Three versions of the questionnaires with choice sets differing only in energy consumption indicators were distributed randomly to 1602 potential consumers in Nanjing, China and a sample of 1569 was obtained after dropping missing data. The analysis with multinomial and mixed logit models reveal that the price premium that consumers are willing to pay for a variable-speed room AC over a constant-speed room AC increases significantly when energy consumption information becomes comparable and additional energy-related information is provided. Furthermore, the impact of information on WTP varies under different energy-saving scenarios. It is suggested that China Energy Label should correct information inefficiency by adopting same energy indicators for room ACs with different technologies and providing energy consumption information based on different climate zones.

IO Standards based Energy Efficient Room Temperature Sensor Design

In this work energy efficient room temperature sensor is designed using various IO standards. This design is implemented on Kintex-7 FPGA, XC7K70T device and FBG676 package. The simulator used is Xilinx 14.6 and Verilog is used as the verification language. The power analysis is done using XPower estimator. The various IO standards implemented in the design are HSUL_12, Mobile_DDR, PCI33_3 and SSTL18_II. The temperature scaling is being done for analyzing the behavior of circuit at different temperature values. The temperature is scaled from 50 o C to 45 o C, 40 o C, 35 o C, 30 o C and 25 o C. There is reduction of 17.39%, 65.22% and 91.30% in IO power when we migrate our design from SSTL18_II to HSUL_12, Mobile_DDR and PCI33_3 IO standards respectively. The maximum reduction in total power is achieved when the design is migrated from SSTL18_II to PCI33_3 IO standard. The reduction in total power is 26.32%, 24.69%, 22.72%, 20.83%, 18.87% and 16.95% at 25 o C, 30 o C, 35 o C, 40 o C, 45 o C and 50 o C respectively when the IO standard is migrated from SSTL18_II to PCI33_3.

Cationic polymerization of isobutylene at room temperature

AbstractThis review highlights recent approaches toward polyisobutylene (PIB) by an energy efficient room temperature cationic polymerization. Special focus is laid on our own work using modified Lewis acids and nitrile‐ligated metal complexes associated with weakly coordinating anions. In both cases, suitable conditions have been found for efficient production of PIB characterized by medium to low molar masses and a high content of exo double bonds as end groups—the typical features of highly reactive PIB, an important commercial intermediate toward oil and gasoline additives. These and other approaches demonstrate that the cationic polymerization of isobutylene is still not fully explored, and new innovative catalyst systems can lead to surprising results of high commercial interest. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Predictions of thermal comfort in stratified room environment

Studies of thermal comfort of occupants started in the early part of the 20th century to describe the comfort level in terms of environmental variables. Field studies have indicated that many of the complaints about unsatisfactory indoor environment can be attributed to the thermal environment. Hence, heating, ventilation, and air conditioning (HVAC) systems are used in buildings to create thermal environments that are capable of providing comfort to the occupants. Among different ventilation systems, displacement ventilation (DV) systems have become popular as more energy efficient room air distribution systems compared with the other more common forms of air distribution systems, such as mixing ventilation. However, local cold discomfort at the lower extremities due to vertical temperature gradient is often reported with DV systems. Although many studies are reported in the literature that compare the performance of the DV systems with the other more conventional types of ventilation systems, the performance of different displacement ventilation types in providing thermal comfort need further investigation. The aim of the current work is to compare the ventilation performance, as predicted by an advanced thermal comfort model, of three commonly used DV air terminal devices (ATDs) for room ventilation: a flat wall diffuser (ATD1), semi-cylindrical wall diffuser (ATD2) and floor swirl diffusers (ATD3). The CBE (Center for the Built Environment at Berkeley) comfort model has been implemented in this study to compare the thermal comfort provided by the three ATDs due to its good performance in non-uniform thermal environments. Based on the test conditions and the results obtained from the comfort model, the predicted occupant’s local sensations for the case of ATD2 were better than those for ATD1 and ATD3 and it showed better overall thermal sensation. Since the local comfort of the CBE model is a function of both local and overall thermal sensations, the predicted occupant’s local comfort values for ATD2 were better than those for ATD1 and ATD3 and consequently it provided better overall thermal comfort.

Energy efficient room air distribution

An environmental chamber has been used to compare the effectiveness of mixing and displacement ventilation in terms of heat and contaminant removal. Results are presented for CFD simulations of the air movement in the chamber and for measurements using a heated mannequin with displacement ventilation. The CFD simulations and the measurements suggest that displacement ventilation is more energy efficient than a mixing system.

Creating an Energy Efficient Room

This document is FCS 3090, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: August 2002. First published: August 1988. Reviewed: August 2002.
 https://edis.ifas.ufl.edu/fy024