Issue 5/2002

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The article puts forward the results obtained by investigation of micro-organism concentration in atmosphere and on solid surfaces and by measurement of dust particles in the hospital atmosphere. Five rooms with different requirements of environment qualities and outside atmosphere were monitored. A correlation was found between the number of particles and the number of bacteria in the atmosphere. The correlation was not found between the number of solid particles and the number of mildew in the atmosphere.

The article brings the description of electric energy reduction in the case of lighting the offices and manufacturing plants. The main emphasis is put on the possibility of lighting varying in dependence on the time of working places utilisation and on the influence of the daylight. By means of the perfect regulating equipment it is possible to reach a saving of more than 70 % of the electric energy consumption together with simultaneous improvement of the working atmosphere from the point of lighting view.

After the technical rules, designer must obligatory calculate the function of natural ventilation in gas-fired boiler house. The contribution deals with the procedure of airing calculation based on the analyse of condition for air flow through the boiler house. The calculation algorithm is written on spread sheet Microsoft Excel.

The article gives the practical procedure of making design of suspended radiant panels heating. It represents the next part of the common calculation procedure published in VVI No. 4/2002, p. 134–138.

The article documents appropriately and unambiguously the dynamic behaviour of panel radiators and compares the following types of connections: two-sided, from above downwards and from below upwards. However the results of experiment need not have strong ties only to by-pass connection with single-tube horizontal heating system (JHOS), but it can concern even the vertical or horizontal two-tube systems only with regard to inlet and outlet tubes connection to radiator.

The author gives an integral view of problems of fire ventilation of buildings. The author informs the readers about terminology used in legal regulations and the latest legislation. The stress is put on main principles of preliminary and final designs of fire ventilation for all types of fire sections.

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The carrying out the duty of securing the easy-accessibility design of buildings for physically handicapped persons has gradually become a part of our building law. The requirements of easy-access solution of sanitary technical installations (ZTI) in different types of buildings are indicated and commented.

Simple and cheap smoke visualization experiment renders primarily qualitative results. The method can contribute significantly to the understanding of mechanisms involved in flow fields. Moreover, it can be helpful in the selection of the flow parameters and regions of interest for local and detail point measurements. The visualization can be very beneficial for a precise adjustment of a chosen flow field pattern in a test section if alternative flow field modes are possible. Typical cases are unstable, bistable and hysteretic behavior of complex flows, when the boundary conditions are not sufficient for the flow field definition. Smoke visualization can be used as a recommendable initial step of various experimentations. The paper shows ten typical examples of „Smoke-Wire Visualisation“ of jet and wake flows, namely jets and impinging jets (including fluidic and acoustic control), and non-isothermal wake flows behind heated or cooled cylinders.