Issue 2/1994

The paper deals with evaluation of function of 11 abroad made filtration apparatuses determinated for indoor air cleaness and IAQ improvement. Dust collection efficiencies of the apparatuses have been evaluated. Air f1-ws (air capacities), noise levels, ozone concentrations and Iight negative ions concentrations in the air have been investigated too.

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The method favourable to air flow determination from the balance equation of non-stationary ventilation is presented in the paper there. The method of the interative calculation is after modification of the basic equation demonstrated on the example of the circulation air fi/ter there. The paper completes the analysis of problems of in- time-variable ventilation which have been published in VVI3/93.

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Requirements and angles of view for choice of suitable venti/ation systems for stable of agriculture in the Czech Republic are discussed in the paper. Representative ways of na tura I and mechanical venti/ation systems suitable as for reconstructed stable bui/dings as for new ones are presented there. The systems consider energy savings need and the ways of venti/ating with the best environmental results for the shedding cattle are accented. Perspectives in the branch of technics of stable environment are discussed in the paper there.

Methods of average equivalent volume radon activity (radon daughters products) estimation and results of an application of one of the mostly used method (track detectors) are described in the paper. Measurement of the instantaneous values of this quantity (air sampling through a filter and filter activity measurement) is losing importance nowadays with regard to ascertained variability of values in the majority of the cases. The method of determination of the instantaneous value of the radon concentration by means of scintillation chambers is mentioned there with respect to its importance for determination of soil radon and radon in water. Causes of concentrations higher than average are commented together with the possibilities of their reduction there (although experience in this field is not extensive in the Czech Republic).

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Ways of capacity control of steam-water heat exchangers are described in the article, asset and drawback of their insta/lation in central heat supply systems are discussed there too. Experience with operation and control of the heat exchangers is presented there.

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