Thermal analysis of rooms with diurnal periodic heat gain.

Temperature and cooling demand in a room summertime are influenced by numerous factors,like internal gains, ventilation, solar gain, behaviour of occupants, thermal inertia of the roomand outdoor conditions (climate).The thermal environment and cooling demand summertime are often analysed using detailedcomputer programs, which take into account the factors mentioned above (among others).Often the overview, transparency and some of the physical insight is lost using these advancedcomputer programs.In a predesign phase of a project it is preferable to do simple calculations of the thermalbeha

On the ventilation and daylight efficiency of various solar shading devices.

Solar control devices placed in front of large building openings disturb air flow and theradiation transfer. Although solar radiation transfer through obstructed openings is arelatively well researched area, very little information is available regarding the air flowperturbations and daylighting alterations created by external solar control devices. Thepresent paper reports a series of experiments aiming at investigating natural ventilationand daylight phenomena associated with the use of specific shading devices.

Office night ventilation pre-design tool.

NiteCool was developed under the Energy Related Environmental Issues in Buildings(EnREI) DOE Programme and is designed especially for the assessment of a range of nightcooling ventilation strategies. The program is based on a single zone ventilation model and isconfigured to analyse a 10m x 6m x3m cell of an office building. It is intended to be used atthe early stages in the design process to help the designer to make informed decisions on theconstruction, opening configuration and operation of the building.

Predicting envelope air leakage in large commercial buildings before construction.

The concept of 'build tight - ventilate right' requires minimising air infiltration through theenvelope of a building and then providing adequate ventilation in a controlled manner tosatisfy the fresh air requirements of occupants. This paper describes a simple-to-use designtool (PC based and in spreadsheet format) for predicting the airtightness of office buildingenvelopes either at the design stage or before a major refurbishment.

Deterministic and non deterministic methodologies for the prediction of the air velocity in single sided natural ventilation configurations.

An extensive experimental program on single sided natural ventilation was carried out within the frame of PASCOOL EC research project. Within the frame of these activities, four single sided natural ventilation experiments were carried out in a cell test, a full scale outdoor facility. Experimental data were used as input for numerical simulations that were carried out using air flow calculation tools based on network modeling as well as computational fluid dynamics (CFD). Finally, fuzzy logic techniques were used to predict the air velocity profile in the middle of the opening.

Heat pipe heat recovery for passive stack ventilation.

Four types of heat-pipe heat recovery systems were tested for application in passive stackventilation. The effects of fin shape, pipe arrangement and air velocity on the heat recoveryeffectiveness were investigated. The air velocity was found to have a significant effect on theeffectiveness of heat recovery; the effectiveness decreasing with increasing air velocity.The pressure loss coefficient for heat pipe units was also determined.

Passive cooling by natural ventilation, salt bath modelling of combined wind and buoyancy forces.

We examine conditions under which the natural forces of wind and buoyancy may beharnessed in order to provide ventilation for cooling. Steady-state, displacement flows drivenby combined buoyancy and wind forces are simulated at small scale in the laboratory using aPerspex box to represent a generic room or single-spaced building. Density differencesnecessary to simulate the stack effect are produced using fresh and salt water solutions. Windflow is simulated by placing the box in a flume tank; the flume produces a flow of water pastthe box and this flow is used to represent the wind.

A design tool for natural ventilation.

A difficulty when designing natural ventilation in office buildings is the lack of simple designtools.In order to be able to predict natural ventilation air flow rates and indoor air temperatures atthe design stage, a computer model has been developed within the EU-JOULE projectNatvent (TM). The program is an integrated model with a thermal and an air flow modelcoupled together.

Controlling ventilation and space depressurization in restaurants in hot and humid climates.

Testing was performed in 9 restaurants to identify uncontrolled air flows and pressureimbalances, building and duct system airtightness, building air barrier location, pressuredifferentials, building air flow balance, and ventilation rates. All restaurants are depressurizedunder normal operating conditions, ranging from -1.0 to -43 pascals. Space depressurizationis a function of exhaust fan flow rates, missing or undersized make-up air, intermittentoutdoor air caused by the cycling of air handlers, dirty outdoor air and make-up air filters, andbuilding airtightness.

Airtightness of new Belgian dwellings - an overview picture.

In the framework of the Flemish Impulse Programme on Energy Technology (VLIET), the project called SENVIVV is running from January 1995 till September 1997. The major objective is to obtain a detailed picture of various characteristics of dwellings constructed during the period 1990-1995. To achieve this, a representative sample of 200 dwellings is analysed in detail. The final report of this project is expected to be available at the end of 1997.

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