This article presents a comparison of commercial and model based predictive control strategies aimed at optimizing efficiency of classical heating systems used in greenhouse temperature control. Two kind of heating systems are considered: aerial pipes with hot water and air-fan heaters. By using simple linearized models of the system around the predefined setpoints and a generalized predictive ...

We examine the control of air pollution caused by households burning wood for heating and cooking in the developing world. Since the problem is one of controlling emissions from nonpoint sources, regulations are likely to be directed at household choices of wood consumption and combustion technologies. Moreover, these choices are subtractions from, or contributions to, the pure public good of a...

It is shown that ac discharges propagating at an air / dielectric interface, though of planar structure, behave, till a critical voltage Vcrit, as corona discharges in an air gap, with similar propagation fields for the filamentary discharge components and similar glow components. This leads to consider the surface discharges as gas discharges propagating above the dielectric surface. Beyond Vc...

Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for house...

Building occupancy is an important basic factor in building energy simulation but it is hard to represent due to its temporal and spatial stochastic nature. This paper presents a novel approach for building occupancy simulation based on the Markov chain. In this study, occupancy is handled as the straightforward result of occupant movement processes which occur among the spaces inside and outsi...

A hydrodynamic vortex separator (HDVS) has been modelled using computational fluid dynamics (CFD) in order to accurately determine the residence time of the fluid at the two outlets of the HDVS using a technique that was developed for use in heating, ventilation, and air conditioning (HVAC). The results have been compared with experimental data [1]. It is shown that, in using CFD, it is possibl...

BACKGROUND Several studies demonstrated a short-term association between ambient temperature and blood pressure. However, few studies have assessed the long-term effect of ambient temperature on children's blood pressure. The present study aimed to investigate the association between long-term exposure to local ambient temperature and children's blood pressure in China. METHODS We analyzed th...

A significant step in the design of Heating, Ventilating, Air Conditioning, and Refrigeration (HVAC-R) systems is to calculate the room thermal loads which often vary dynamically. A self-adjusting method is proposed for real-time calculation of heating/cooling loads in HVAC-R applications. In this method, the heat balance calculations are improved by realtime temperature data to achieve more ac...

As much as half of the energy used in home goes to heating and cooling. So making smart decisions about heating, ventilating, and air conditioning system can have a big effect on utility bills. Saving energy at home also can help to protect the environment. It is at this critical moment that semiconductor suppliers are playing an important role in developing technologies that improve energy eff...

The microstructural analysis of Thermal Barrier Coatings, deposited according to the Air Plasma Spray technology, furnishes information according which a strong orthotropic thermal conductivity is expected to be measured for such a material. Pulsed experiment with a localized heating source and thermographic temperature recording, permit to evaluate both the in-depth and in-plane components of ...