One of basic principles in designing treatment environments is to design air conditioning/ventilation system proportionate to environment. Essentially, appropriate air conditioner in treatment spaces must bear the following capabilities: providing healthy and clean air, reducing the concentration of pollutants produced in the atmosphere, emission of pollutants and impeding their spread in exter...

The objective of this paper is to estimate the potential for electricity savings with the use of daylighting integrated with the artificial lighting system and hybrid ventilation in commercial buildings located in Florianópolis, southern Brazil. Several models were analysed. Two cases were investigated: a reference case, operating only with air-conditioning system and another one with the use o...

One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with ...

The main objective of this work is to develop a method for sizing window area based on the consumption of electricity in commercial buildings, when integration of daylight and artificial light with hybrid ventilation is considered. The method allows the estimation of the potential for electricity savings and the evaluation of the daylighting performance. Models operating with artificial and nat...

Design and operation of an extended hybrid ventilation system are fully investigated in this study through an example building. Tools of genetic algorithm optimization, computer fluid dynamics and energy simulation are employed to assist the process. The objective is to maximize natural ventilation while maintain good indoor thermal and air quality. The dynamic operation of vents is based on wi...

Buildings and their related activities are responsible for a large portion of the energy consumed in China. It is therefore worthwhile to improve the energy efficiency of buildings. This paper describes a low energy building design in Hangzhou, south China. A hybrid ventilation system which employs both natural and mechanical ventilation was used for the building due to the severity of the clim...

A key component in low energy houses is the heat recovery from the ventilation air. Over recent years, the most frequently used ventilation type is the mechanical ventilation with heat recovery. This kind of ventilation results in high heat recovery but does unfortunately consume a considerable amount of electrical energy. Natural or hybrid ventilation has the potential to consume less electric...

The need for conventional mechanical ventilation (CMV) is a common one in the neonatal intensive care unit (NICU). The goals of CMV are to facilitate adequate gas exchange, minimize the risk of lung injury/damage, decrease the patient's work of breathing, and optimize the patient's comfort. Although time-cycled, pressure-limited ventilation remains the most common CMV modality, volume-cycled ve...

Ventilation barriers allowing simultaneous sound blocking and free airflow passage are of great challenge but necessary for particular scenarios calling sound-proofing ventilation. Previous works based on local resonance or Fano-like interference serve a narrow working range around the resonant destructive-interference frequency. Efforts made broadband designs show limited bandwidth typically s...

J. M. Wild, N. Woodhouse, K. Teh Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom Introduction: Measurement of the He gas ADC with pulsed gradient methods can identify empysematous changes in lung structure at the alveolar level [1]. Ventilated airspace volumes derived from segmentation of ventilation images are also of use in identifying and quantifying obstruc...