Ultraviolet germicidal irradiation (UVGI) systems are used to disinfect air, they consist in mounting shielded UVGI lamps at high level in an upper room zone, and the natural convection currents that occur in a room space carry airborne microorganisms through the UV field. This study demonstrates that the effectiveness of those systems is dependant on both the ventilation regime and the in-room air mixing.
The aim of that study is to establish characteristic building parameters and to analyse the night ventilation effect with these parameters. Measurements were made thanks to a parametric model and a building simulation programme.
The distribution of the humidity in a dwelling unit is the key factor determining the condensationrisk and the mold growth, as well as the dryness problem. As the first stage of the research project aiming at the understanding and the solutions of the above problems, the experiment on humidity distribution in multiple rooms with the simulated occupancy was carried out in a full-scale research house. The effects on the humidity distribution of the ventilation, etc. are described and compared with the numerical predictions.
A ventilated cavity wall is often proposed in the building envelope design as an alternative to thetraditional wall, mostly due to its ability in reducing the thermal load during the hot season. In order to be recommended as a solution for improving the thermal comfort, a thorough analysis of its performance under all possible scenarios is required. For assessing the thermal performance of the cavity wall, an experimental model has been built and tested at the DECivil of IST.
This paper provides information of energy efficiency potential of Personalised Ventilation (PV) systems used in conjunction with a secondary Mixing Volume (MV) air-conditioning system in the tropics. The energy consumption and the acceptability of PV at selected combinations of indoor ambient temperatures of 26 C and PV air supply temperatures of 20 or 23 C, is compared with that of sole mixing ventilation in which the indoor air temperature was controlled at 23 C.
Isolation rooms for airborne infectious agents requires special measures to prevent air from transporting agents from the patient to surrounding rooms. This paper presents measurements for two different solutions that demonstrate that good results could be obtained by selecting construction principles that prevents air leakages and by control of ventilation airflows interlocked to door positions. Further it is estimated how different parameters influences on the transfer of infectious agents from the patient room to the surroundings.
The object of this investigation is a marketplace in a cold winter and hot summer region. This survey provides some basic data for HAVC designing of marketplace and the improvement of existed HAVC system in cold winter and hot summer region, at the same time it is suggested:
1. Due to bad smell caused by fruit and vegetables, it is suitable for supermarket to adopt deterministic directional airflow.
Tracer gas sorption in and permeation through building materials influence tracer gas ventilation measurements. The permeation of the commonly used tracer SF6 through three different building materials (gypsum board, wood particle board and MDF-board) with and without paint has been experimentally investigated. The results show that the tracer diffuse through untreated boards and that gypsum board has the largest permeability towards SF6. However, the diffusion rate of tracer is effectively reduced when the boards are coated with two layers of latex paint.
We report on a series of measurements of the temperature at Houghton Hall, Luton,over the Spring and Summer of 2003. The data show that the building tracks the externaltemperature, but that the amplitude of diurnal temperature fluctuations typically lies within 2-6 C,while the external fluctuations may be as large as 15-25 C. This buffering of the internaltemperature is largely due to the thermal mass of the space which introduces a time-lag ofbetween 0.5-3.0 hours in the response time of the interior to the exterior space, over the periodof our survey.
This paper describes a study on the performance evaluation of a hybrid ventilation systemwith a heat exchanger. This system has two passive stacks and a heat exchange unit, which includes a heat exchange element, a supply fan, an exhaust fan and a bypass route with a damper. In order to evaluate the system performance, the experiments and numerical simulations using a full-scale test house have been performed in winter or mild seasons. In the result, the ventilation rate and the heat recovery rate under the various conditions of the fan and the damper operation were clear.
Login