Issue 3/2003

The article informs about knowledge based on measuring one-pipe heating system with connections with radiators bypasses. On basis of experiments the author recommends the optimum water velocity in basic pipe and informs about dynamic behaviour of the system due to regulation interventions.

The article presents the properties of dark and light gas radiators and the rules of correct designing. Further, the typical properties and parameters of particular radiators delivered by author’s firm are indicated.

The author presents analysis of the temperature difference proposal influence on heat output of radiators. The dependencies of heat output changes on heat transfer medium flow changes are indicated in charts. As a result of analysis the temperatures of water supplied to radiator were supplemented by 50 up to 65 oC and the water cooling down in radiators by 20 K.

The article presents relations enabling to create mathematical model of solar liquid collector. The procedure is described from two point of views; external absorber energy balance and internal energy transfer by fluid.

The article deals with experimental research results of reinforced exhaust system formed by combination of two types of flow. By balanced combination of momentum flows of the supplied and exhausted airs there is possible to change markedly the form and the size of exhausting effective area in front of the reinforced exhaust hood, which is markedly longer effective exhaust area than with the traditional flanged exhaust hood. The results of the research may be utilised for example at welding plants of automobile industry, where the largeness, diversity of forms and use of welding technologies often prevents from optimum exhausting harmful substances dangerous for health.

The contribution deals with the most widespread stationary fire-fighting equipment avoiding fire spreading already on its beginning. Its use is connected with high requirements of water supply, quality and professional design and even erection proper. Sprinkler equipment is active already on the beginning of the fire broken out when it is started automatically without human factor intervention and in this way decreases the damages caused by fire to minimum.

The aim of the article is to contribute to more precise use of terms „hygienic equipment“ and „social equipment“. Architects, civil engineering and other specialists working in the sphere of designing, authorising and executing constructions often confuse these terms and are not aware of the fact of their substantial difference.

The article presents common rules for pumping heat out of vertical earth drill holes with heat exchangers and for the reverse process – storing the heat from these drill holes back into the earth’s half-massif. The description of the equipment, implemented at the Czech Technical University in Prague, Faculty of Mechanical Engineering, enabling these both functions is presented.

The article deals with a brief description of the road tunnel Mrázovka in Prague ventilation and composition of operation ventilation simulation. Without detailed analysis of the calculation algorithm it presents important simulation results and draws the attention to the importance of the composition importance of optimisation and simulation algorithms for economy evaluation of the operation system and for making the tunnel ventilation draft design more precise. The results of computer simulation of the aerodynamics of the proposed longitudinal ventilation are indicated that should prevent the escape of harmful substances through the portals. The results are utilisable for composition of control algorithms of ventilation system with continuously controllable fans in three machine rooms and jet fans with supporting or braking impact on air flow in tunnel body. The calculation was elaborated in Microsoft Excell with the support of Visual Basic.

The project includes 23 low energy multiple row family houses. Primary heat source will be boiler for biomass burning. There is an integrated greenhouse at the south facade of each house. Linear Fresnel lenses solar collector SOLARGLAS 1 will glaze the sloped surface of greenhouse. This system eliminates the solar insulation peeks, facilitates TUV heating and provides comfortable lighting of the interior.

The article informs about using of perfumes in the history of people. Formerly perfume was used for masking unpleasant smells, as substitution of personal hygiene, by religious ceremonies and by treatment of illnesses. Today pleasant odour is factor of environmental comfort and complement of daily hygienic measures.

The contribution deals with the study of low/frequency electromagnetic field emission (ELF ELM F) generated by the wall air conditioning equipment of the firm Hitachi VRV type. The emission ELF ELM F intensity of the ceiling air conditioning units of the firms Heizbösch, Carrier, Toshiba and KVKA 315MTW has been measured. The emission level has been compared to ELF ELM F reference values indicated in the decree of the government 480/2000. By means of magnetometer EFA 300 the under-limit value of low-frequency electromagnetic field emission was detected and that as far as the magnetic induction magnitude and also electric field intensity magnitude concern.