norhayati mat wajid

PurposeCommercial buildings, which include office buildings, are one of the three major energy-consuming sectors, alongside industrial and transportation sectors. The vast increase in the number of buildings is a positive sign of the rapid development of Malaysia. However, most Malaysian government office buildings tend to consume energy inefficiently due to lack of energy optimization. Most of the previous studies focused on the performance of green buildings in fulfilling the green development guidelines. As such, it is essential to study the energy performance of existing government office buildings that were constructed before most energy-efficient standards were implemented to mitigate energy wastage due to the lack of energy optimization. This study aims to analyse the energy performance of existing non-green Malaysian government office buildings and the factors that influence building energy consumption, as well as to evaluate the efficacy of the existing energy conservation ...

The high energy demand to accommodate heating and cooling in buildings has put tremendous pressure on research to develop more ‘greener’ heating and cooling systems. The conventional vapour compression systems became desirable for new and existing buildings for heating and cooling application because the system is well developed and commercially available. However, these conventional systems consume high energy and are considered not environmentally friendly with the usage of hydrofluorocarbons as refrigerants. On the other hand, thermochemical adsorption heat pumps are thought to be alternative solutions. However, some limitations such as low thermal conductivity in the adsorbent bed is one of the problems that this new technology would face in competing with the conventional heating and cooling systems. Thus, this review would emphasize on various techniques investigated by many researchers on solving low thermal conductivity and the various methods on enhancing heat and mass tran...

Heating and cooling account nearly 60% of world total energy consumption and highly depending of conventional energy sources generated by fossils fuels. As the scarcity of oil reserves becomes the jargon issues in all part of the world today, researchers have to look into a robust investigation on finding the alternative energy to alleviate the dependency of conventional energy. Furthermore, if the phenomenon of using fossil fuel remain as the primary energy sources, it would affect adversely on the greenhouse gas emission. In 2008, The Climate Change Act by the UK Government had targeted that 34% cut in 1990 greenhouse gas emissions by 2020 and, at least, an 80% cut in emissions by 2050. Therefore, to achieve this target, more low carbon technology needed to realise the future reduction of emission. Renewable energy technologies such as solar, wind, geothermal and such thought to become the solution to reducing the demand for conventional energy. However, their instability consider...

One of the areas that present an opportunity to reduce the national carbon emission is the energy management of public buildings. To our present knowledge, there is no easy-to-use and centralized mechanism that enables the government to monitor the overall energy performance, as well as the carbon footprint, of Malaysia’s public buildings. Therefore, the Public Works Department Malaysia, or PWD, has developed a web-based energy performance reporting tool called JENOSYS (JKR Energy Online System), which incorporates a database of utility account numbers acquired from the utility service provider for analysis and reporting. For test case purposes, 23 buildings under PWD were selected and monitored for their monthly energy performance (in kWh), carbon emission reduction (in tCO2eq) and utility cost (in MYR), against the baseline. This paper demonstrates the simplicity with which buildings without energy metering can be monitored centrally and the benefits that can be accrued by the gov...

Novel EVM/SrBr2 composite sorbents with different salt contents were developed for low-temperature thermal energy storage (TES). Simulative sorption experiment was conducted to obtain the sorption kinetics diagram and identify threshold salt content that composite sorbents can hold without solution leakage. Distribution of salt embedded in EVM was observed by extreme-resolution scanning electron microscopy (ER-SEM). Thermochemical characterizations including desorption performance and desorption heat were fully investigated by analyzing simultaneous thermal analyzer (STA) results. Results reveal that sorption process of composite sorbents is divided into three parts: water adsorption of EVM, water adsorption of SrBr2 crystal and liquid-gas absorption of SrBr2 solution. Since SrBr2 solution can be hold in macrospores of EVM, water uptake and energy storage density are greatly increased. It appears that the composite sorbent of EVMSrBr240 is a promising material for thermal energy storage, with water uptake of 0.53 g/g, mass energy storage density of 0.46 kWh/kg and volume energy storage density of 105.36 kWh/m3.

ABSTRACT This paper presents the results of experiments conducted to investigate the performance of a novel thermochemical energy storage pumping pipe system (TESPP), using two different synthesised composite adsorbent materials. A laboratory test rig pipe system comprising of two sections namely ; adsorption and evaporation sections, sepated by a valve, was designed and constructed. The test rig was experimentally tested using composite adsorbents ; vermiculite and calcium chloride, and silica gel and calcium chloride. Experimental results showed a high temperature lift in adsorbents due to moisture adsorption in the test rig system, up to 67-72°C from an initial temperature of 20°C, when both adsorbents were used. The TESPP system could utilise off peak power or other low grade thermal energy sources for charging/adsorbent regeneration. The results also indicated that the novel system has the potential for high thermal energy storage and could be used for building heating and hot water application.

... All rights reserved rergamon Printed in Great Britajn PII: S0734-743X(98)00018-9 0734-743X/98 S - see front matter AN EXPERIMENTAL STUDY ON THE SCALING OF PLATE CUTTING WQ SHEN*, KW FUNG, P. TRIANTAFYLLOS, NM WAJID and N. NORDIN Department ...

Adsorption heating/cooling became an alternative to vapour compression system due to low ozone depletion potential (ODP) and global warming potential (GWP). However, more investigation is required due their low efficiency when compared to conventional heating/cooling systems. This review emphasizes on the mathematical modelling simplification and heat transfer enhancement method that applied by many researchers to improve the performance of adsorption heating and cooling technologies. Various techniques investigated by many researchers on solving low thermal conductivity and the different methods for enhancing heat and mass transfer in the adsorbed bed/pipe also discussed. Common techniques used to enhance heat and mass transfer in the adsorbed bed/pipe include the fin type adsorbent tube/ heat exchanger, amalgamated adsorbent bed with a metal foam, consolidated adsorbent, adsorbent coating and adsorbent with multi cooling tubes. Other than that, recent advancements in adsorption co...