Issue 3/1999

Author gives survey of the influence of wall recess, parapets, coverings, installation height of radiator and its distance from peripheral wall on radiator output.

Author deals with dynamic behavior of heating systems with heat pump. He presents in details the characteristic of the impact of control interventions at heat consumption side of heating system on heat pump running and its effectiveness measured by coefficient of heat pump performance. Author analyzes influence of building structure heat accommodation and defines conditions under which building structure heat accumulation is already not sufficient to observe the maximum admissible number of four switchings of heat pump in one hour. In such cases it is necessary to put an additional accumulator between heat pump and heating system.

The article is reaction to the paper published in VVI Joumal No. 1 and 2/99. The authors presents new progressive methods of steam heaters and steam to water heat exchangers, used in industrial halls heating.

The issue of heat costs proportioning indicators is discussed with focus on their location and design, and reading of indicated quantities.

The paper clears up problems of application of refrigerants R 134a and R 407c as environmentally friendly substitutes of refrigerant R 22. By results of refrigerating equipment measurements influences of new refrigerants are documented on compressor capacity parameters, heat transmission conditions in condenser, evaporator capacity and also refrigerating unit capacity and coefficient of pertormance.

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ln the paper the basic information is summed up on procedure and introduction of system EMAS in enterprises of the Czech Republic. Audit according to EMAS or according to ISO 14000 wHI be necessary in the near future especia/ly with those enterprises that want to export their products abroad, or it will be necessary to prove that inadequate viola­tion of environment is not taking place and in this way to stand up to accusation of environmental dumping.

Contribution deals with problems caused by insufficient apartment ventilation in cases when windows were replaced by more tight ones - without consideration of ventilation needs. ft refers to discrepancy between decrease of heat losses by infiltration and depreciation of indoor atmosphere. Suitable window designs enabling controlled ventilation are indicated. Results of ventilation intensity measurements are indicated by authoress.

Paper presents results of investigation of bacteria and mildews concentration in atmosphere. Concentration of microorganisms has been monitored in households, offices and schools, apartments with occurrence of mildews on walls, in hospitals, one gymnasium and at one workplace. Increased concentration of microorganisms was found in apart­ments with mildewed walls, old hospital buildings, during gymnastic exercises, in case of dehumidifier use and during work with molded grain. ft is referred to fact that installation of technical equipment without ordinary cleaning up will not secure low level of contamination of indoor atmosphere by bacteria and mildews.

The paper points out the drawback of the Czech market: sometimes offering products of doubtful quality but with massive sales promotion. Customers are usually unable to check the announced features of products. This information is concerning particularly the filters used above hydronic radiators.

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The paper deals with efficiency evaluation of air cleaners which were provided within the scope of project "Clean air for flooded Moravia" by power generation company ČEZ and installed through foundation "Fund for social and therapeutic help", registered office in Prague, in selected interiors of children's homes. For evaluation of effectiveness of chosen apparatuses on quality of indoor atmosphere the children's home in Ostrava-Hrabová was chosen. ft results from conclusions that air filters represent here efficient measure.

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