Describes an analytical model for the prediction of ventilation rates and internal temperatures as influenced by the combined effects of heat dissipation inside industrial buildings and natural wind action. Applies this to a two span low building equipped with a natural ventilation system. Results emphasize the relative importance of thermal and dynamic variables including wind incidence, terrain roughness, and the role of the opening in the internal partition wall.
There are several reports on studies of wind tunnel experiments and calculations on the response of air flow at an opening against the periodic variation of wind velocity and pressure. In these studies, the fluctuating components of natural wind velocity have been treated definitely. In this paper, theoretically derives the probability density function from a probabilistic model of wind velocity around the buildings, the consequent wind pressure, and the resulting ventilation rate and contamination concentration.
Describes a wind tunnel investigation of wind pressure distributions over a 1:100 scale model of a single family house, surrounded by identical building models in various regular arrays. Measures time-mean pressures at 122 locations on walls and roofs in a 90 degree wind angle sector. Calculates air change rates and corresponding heat losses for a full-scale building of the same type for a range of wind speeds and outdoor air temperature. Uses the full number of local pressure coefficients for the building surfaces as input data.
Presents an analytical model for the prediction of ventilation rates, internal pressures and temperatures as influenced by the combined effects of heat dissipation inside industrial buildings and natural wind action. The model inputs are external pressure distribution, pressure drop coefficients of theopenings and thermal conductance of the walls and roof assumed to be knownfrom experimental data. A simple example is worked out. It consists of a two span long building, equipped with a natural ventilation system and divided into two internal spaces differently heated.
States that methods used by Swiss energy consultants in calculating air change rates are often inaccurate. Most consultants use the "observation method" utilising smoke pencils etc. and mistakes are made in calculating conditions causing air infiltration. Describes a new graphic method for estimating mean air change rates, which needs data on construction, pressurization values and window opening.
Studies the ventilation of 9 air-conditioned animal rooms used for both housing and experiments. Samples dust, measures ventilation rate by anemometers and by tracer gas decay, and uses settle plates to determine the number of airborne bacteria. Detects a high amount of pariculate matter emanating from the animals which might sensitize personnel working in these rooms. Previously, attention has been paid to the ventilation requirements of the animals but where people also spend several hours in animal rooms then safety conditions for staff must be considered.
Measures the air change rate in 2 atrium houses and in 6 terrace houses. Examines the possibility of allocating the air change to particular rooms by correctly placed and operated exhaust ventilation and ventilation openings. Concludes that in dwellings with mechanical exhaust the fresh air change rate only depends slightly on the ventilation openings being opened or closed, and that it is possible to direct fresh air flow into different rooms if the doors within the house are not tight.
Describes a computer program developed for the analysis of residential building thermal loads and space heating and cooling energy use. It is capable of modelling the simultaneous heat balances on multiple spaces, building air flows by infiltration and natural and forced ventilation, including thermostatically controlled through the house ventilation, detailed solar gain, part load performance of central and unitary heating and cooling systems, and thermostat droop and cycling characteristics.
Measures air change rates in a 2-storey detached house with operation of various types of mechanical fresh air ventilation systems. Studies 4 systems, including 2 balanced systems and 2 exhaust-only systems. The forced ventilation rate is controlled at 0.15, 0.25, 0.4, or 0.5 ach. Develops expressions for the test house relating the house air change rate under winter conditions to the forced ventilation rate and the infiltration rate due to wind and temperature difference.
Discusses the Hjortekar project of 6 low energy houses, built as part of the Danish Energy Research and Development Programme. Explains some of the construction details to avoid cold bridges and ensure airtightness. Test results of infiltration air change rates range from 0.02 to 0.12 ach, while other tests show less than 15% difference between calculated and measured transmission heat losses, which range from 70-155 w/degree C.
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