This paper presents a conceptual design of a multizone hvac controller based on a wireless sensor network that aims to optimize energy consumption while maintaining the comfort level of users. The proposed system is capable of learning the occupancy pattern of the residents in the building. Moreover, it is transparent (requires no manual configuration). Wireless sensor network technology is used to collect the required measurements for the control system. simulation results are used to demonstrate the system performance in terms of power consumption and comfort level. Additionally, a comparison between the proposed system and other hvac control systems is presented. The results show that the proposed system is capable of providing a major energy savings.I. INTRODUCTION There is an increasing demand for Heat Ventilating and Air Conditioning (HVAC) systems due to the increasing population and global warming and many other serious reasons. Energy conservation becomes a very important problem to be addressed as it affects the local and global quality of life.Researches have made efforts to improve air quality produced by HVAC units [1][2][3]. However, to date there is no cost efficient commercial utilization of this technology. HVAC systems are large consumers of energy, resulting in high electricity bills. HVAC systems consume around 5000 of the total electrical energy generated in the world [4]. Hence, it is very important to optimize the energy consumption of the HVAC system by maximizing energy utilization. Recent studies showed that commercial buildings could reduce energy usage between 15% and 400O by closer monitoring and managing its energy usage [5]. The centralized control of HVAC system has an inherited weakness by allowing the energy to be distributed equally around the serviced zones. This causes a considerable amount of energy to be wasted. Therefore, an intelligent HVAC control is required to minimize the energy consumption and optimize the comfort level.Several studies have been conducted to optimize the energy consumption of HVAC systems [6][7][8][9]. However, these systems are not adaptive to user behaviors [6,7] or they are too complicated to be implemented in a simple embedded system if they are used for multizone buildings [8,9].Although there are some advanced control solutions that provides programmable configuration such as operation time and multiple set points, these systems fail to achieve their main purpose, energy saving, for several reasons. First, these programmable controllers require product education. The limited interface associated with these systems drives the customers to read the product operating manual to figure out how to configure the system to work according to their preferences. Moreover, these controllers are not adaptive. They adhere to the manufacturer's configuration and do not adapt to the customers changing schedule or other new activities that require reconfiguring the system to accommodate these updates. Therefore, many people end up using these programmable system...

Transparent, conductive indium-tin oxide (ITO) and tin oxide thin films were deposited on soda-lime-silicate (SLS) float glass and silica glass substrates by an RF aerosol plasma technique in an atmospheric environment. The ITO films were deposited from solutions with various In: Sn ratios. The dependence of the film properties on the substrate temperature, deposition time, and tin concentration has been studied. The films were characterized by several techniques including XRD, EDS, electrical resistivity, SEM, optical (IR-UV-Vis transmission), Mössbauer, and infrared spectroscopy. The results showed that film phase, morphology, thickness, crystallite size, and conductivity depend on the solution composition and deposition parameters. XRD revealed that In2O3 was present in the film when a In: Sn ratio of 5: 5 or higher was used; otherwise only SnO2 shown. SEM analysis showed that dense and uniform films were formed with particle sizes ranging from approximately 50 nm to 150 nm. The resistivity of the ITO films ranged from 0.12 to 5.0 ohm-cm at room temperature. Optical transmission of the ITO-coated glasses was not different from the uncoated samples. Infrared results indicated that the structure of the near surface of the glasses was significantly modified with a higher indium concentration. The advantages of the atmospheric, RF aerosol plasma deposition process over other techniques are discussed.

No abstract

The discovery of high Tc superconductivity in layered cuprate ceramics has so far led to the identification of about 35 distinct superconducting cuprate systems, the latest of which is the 133 K superconducting system Hg-Ba-Ca-Cu-O. For most of their proposed applications, high Tc ceramics have to be resistant to environmental degradation both with respect to atmospheric water vapor, e.g., in storage, and to liquid water (produced by condensation on warm-up from cryogenic conditions). The presence of CO2 is an important factor in both environments. Increasing environmental stability involves improving the processing methods to eliminate pores, cracks, and other macroscopic defects (e.g., highly leachable impurity phases) which are prevalent in materials prepared by solid-state sintering. Furthermore, protective coatings and hermetic seals are necessary in many applications involving films because of small film thickness. (Wires are usually drawn inside metal tubes, which provide protection.)

No abstract