Displacement Ventilation approach is becomingan interesting alternative to mixing ventilationainong Canadian consulting engineers. Thispaper presents two recent DisplacementVentilation projects designed by two inajorCanadian engineering firms. The designapproach chosen by the mechanical engineers isreviewed and compared to European andAmerican existing Displacement Ventilationdesign guidelines. The paper shows that sometraditional mixing ventilation assumptions arestill prevailing which alter the expected benefitsof the Displacement Ventilation approach.
The paper presents the results of mold growthrislzs in a corner wall near an entrance door inan apartment house. The corner wall isrecognized as a trouble spot for condensationand mold risk in apartment buildings. Thisstudy analyses mold rislzs based on a mixedsimulation approach. This approach requires areliable aggregation method to arrive atquantified mold growth risk and extension ofstandard simulation capacity to account for additional mechanisms of the moldphenomenon.
Energy consumed in the Canadian residential sector for space cooling has more than doubled from 1990 to 2002. Cooling requirements, expressed by cooling degree-days have also increased. In parallel, there has also been a noticeable increase in the penetration rate of airconditioning systems: almost 45 percent of households were equipped with some type of air-conditioning system in 2003. A comprehensive ventilation approach requires not only air exchange but also indoor liuinidity control.
This paper presents a design method to definethe settings of HVAC systems in order toprovide thermal comfort in high MRTenvironment in hot climates. The method,firstly, discuss the use of simplified thermalload calculation methods, in face of thespecificities of the theme. Then, dynamic heat,air and moisture envelope simulations areperformed in order to define the surfaces'internal temperatures. The distribution system,including terminal sizing and positioning, flowrate and temperature, is defined based on CFDsimulations.
In the desiccant dehumidifier using adsorbentsuch as silica gel and zeolite, outdoor moist airis dehumidified in adsorbent. On the otherhands, it is necessary for the adsorbent whichbecomes moist by dehumidifying outdoor air tobe dried (regenerated).
This paper investigates the thermal effect of ceiling-mounted light fixtures for a displacement ventilation system. The influence of fluorescent lainps on a ceiling is examined by computational fluid dynamics and experimental methods. The test room is a 5.3m X 5.44m X 2.5m height office. Two supply air diffusers and two exhaust grilles are dimensioned bv 0.9m x 0.2ni each. A heat source is instailed at the center of the room. Supply air velocity is treated as a parameter from 0.1 to 0.5 mls. The finite volume method and low-Reynolds number k- ?
This paper describes some qf the thinking behind the thermal comfort provisions of the new European Standard EN1 525 1 (CEN:2007) for free-running buildings. This standard deals with all aspects on the indoor environment. The paper will presentthe evidence on which its provisions fortemperature in naturally ventilated buildingsin summer is based. It will discuss theadvantages they present jbr those concernedto design buildings which will minimise theuse of energy.
The aim of this paper is to have a generaldiscussion of the status regarding energybuilding codes in relation to TAQ concerns.First, there is a brief discussion of the trends inenergy regulations and in IAQ concerns. Thenthe objectives and outcome of a recentworkshop on trends in national buildingventilation markets and drivers for change aregiven. This is followed by a brief overview ofsome areas where there might be majoropportunities but at the same time threats.Finally, information about 2 informationplatforms is given as well as some overallconclusions
BEU accounting and assessment is a fundamental task for development of energy efficiency in buildings. The traditional methodology is based on caloric value of energy carriers, which is only relates to energy quantity. To address a comprehensive assessment, an exergy assessment methodology is put forward in this paper. Furthermore, in existing China's statistical yearbook, there is no specific item for building energy use. This paper processes analysis for statistical yearbook and acquires relevant rough data of building energy use.
According to the definition, passive houses inEurope meet a target energy demand for heatingof less than 15 kWh per square meter and peryear. This low level for the heating demand isbased on heating by a small post-heater in thehygienic ventilation system at 52 C maximum,while the ventilation system can be dimensionedpurely for ventilation purposes. In theory thusthe installed heating power is less thanapproximately 10 watts/m2.But what happens in practice?
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