It is the objective of the present paper to investigate indoor environmental characteristics ofan office building with an underfloor air conditioning system. Thermal conditions in the roomwere monitored including horizontal and vertical temperature distributions, supply andexhaust air temperatures, and globe temperature. Indoor air quality was investigated bymeasuring carbon monoxide, carbon dioxide and airborne particulate. Velocity distributionsaround a floor air terminal, and thermal comfort around a supply air terminal were alsoinvestigated.
An efficient ventilation system is characterised by a well-organised and turbulence-controlled airstream that rapidly corrects disturbances in air quality and thermal comfort in the ventilated space.Air supply and exhaust conditions are investigated here in order to find stable flow conditions andan efficient elimination of both gas and solid phase contaminants. Heat and thermal comfortrequirements are also included.
The study was to test five units used in single house mechanical ventilation systems with heat recovery. Tests were made according to CEN project prepared by CEN TC 156/WG2/AH7 including air tightness, pressure-airflow's curves and temperature ratios. A full test on frost and condensation was also realised on one unit to determine the influence of these parameters on performances. Test results, influence of wet or dry conditions and main conclusions for using these results in dimensioning, will be given.
Surveys on repressurization-induced backdrafting and spillage were conducted in threedifferent areas of the United States using a common protocol, primarily to assess thecorrespondence between short-term tests and one week of continuous monitoring per house.The short-term tests, under induced conditions, can only indicate whether there is a possibilitythat backdrafting or spillage might occur, whereas real-time monitoring under naturalconditions can give a true indication of backdrafting and spillage events.
The main objective of this study was to determine the ventilation demand for a gymnasium inthe primary school based on verified metabolic rate.Norwegian guidelines recommend 6.0met as the activity level to be used when calculating the outdoor air flow rate in a gymnasium.Younger pupils have a lower body mass and metabolic capacity than adults, and their demandfor ventilation is therefore lower. The metabolic rate has been assessed by measuring thepupils emission of the dominating bioeffluent CO2 during intensive gymnastic activity.
This article briefly describes a research program undertaken by the National Institutes of Health Office of Research Services to investigate ventilation performance of different laboratory configurations, and their affect on the hood. It focuses on some specific recommendations identified by the work which should help designers optimise performance. The intent is to provide a basis for guidelines to maximise lab hood containment performance, while minimising the impact of the lab layout and ventilation system.
Scale model experiments give possibilities for analyses of the design conceptions of ventilation especially of air distribution in large enclosures. When simulating aerodynamic and thermal processes in scale models of room ventilation, the flow patterns are visualised and the air flow temperature and velocity are measured. The paper presents the results of experimental tests of the air mean velocity field in three different size models of the same ventilated room. The field maps of the air velocity mean value were analysed.
The purpose of this study was to evaluate the indoor air quality parameters in a residentialdwelling using information from the field. The subject was a typical example of the modernItalian dwelling stock, built in the 1980s in a residential area in the northernpart of Rome.The dwelling was constructed from pre-cast panels using industrial building techniques. Thewindows were steel-framed and painted. Airtightness was measured to obtain the ACH (airchanges per hour) at 50 Pa pressure difference, and ELA (equivalent leakage area).
The objective of this research is to investigate thermal comfort and air flow distribution insidea test room which is naturally ventilated. The test room is ventilated through adjustablelouvers. The air pressures and velocities across the openings together with indoor airtemperature and mean velocity at four locations and six different levels are measured. Thecollected data are used to predict thermal comfort parameters across the test room. Tests werecarried out over the winter and summer time.
An efficient numerical method for solving the Reynolds-Averaged Navier-Stokes (RANS)equations with turbulence models for complex geometry and high Reynolds number flows isused to perform a highly-resolved computation of the turbulent flow in a strongly curved partof a ventilation duct.The three-dimensional incompressible RANS equations and the isotropic k-w two-equationnear-wall turbulence closure are written in generalized curvilinear coordinates in the strongconservation form.