Issue 1/2005

The article informs about the course and character of heating period 2003/2004 in Prague. On the basis of climatic elements measured at the Praha-Karlov observatory the values of quantities necessary for the calculation of heat demand for heating were determined by the degree-days methods for the indicated period and its energy demandingness was evaluated in comparison with the previous heating period and with the fifty-year averages. Further selected data illustrate the climatic conditions in Prague and outline also the weather character in the course of this period in the whole Czech republic.

At the present a few types of radiant panels are available at the market at the field of electric radiant heating. The object of this technical article is the presentation of experimental operation measuring of electric radiant panel manufactured of dielectric plate of 2 mm thickness. The aim of this measuring was to determine the following 5 physical parameters: temperature-voltage relation, characteristic wave length, surface emissivity (coefficient of emissivity determination), radiant output in dependence on voltage and current characteristics, radiation-convection relation. With regard to the extensiveness of the results of experimental measuring, only those results are presented that are oriented to determination of emissivity coefficient and also to determination of radiant output in dependence on voltage and current characteristics [9].

The presented article brings the intricate problems of the design of ventilation equipment for health service to the reader. In the Czech republic the adequate legislation is not at designer’s disposal, in existing legal documents the requirements are defined insufficiently and sometimes also antagonistically. The author summed up some problems that have to be solved by the designer and draws the attention to risks connected with the designing of ventilation equipment for health service. The communication represents the introduction to the series of articles dealing with the given subject.

-

-

Recent laboratory and field experiments show that improving indoor air quality improves the performance of office work and thus productivity at the workplace. In the laboratory studies recruited subjects performed office work in offices where the air quality was improved by reducing the pollution load and increasing outdoor air supply rate. For each 10%reduction in percentage dissatisfied with air quality a 1% increase in performance of office work was observed. In the field studies the talk-time of operators was registered in call-centres where the air quality was improved by increasing outdoor air supply rate or replacing a used ventilation particle filter with new one. These interventions improved work performance by 5 to 10 %. To examine whether the observed benefits from improved worker performance exceed the costs required to improve air quality, life-cycle costs analysis was carried out. Although it showed that the air quality upgrades increase energy and maintenance costs, first costs of a HVAC system and building construction costs, they were shown to be highly cost-effective: productivity benefits were many times higher than the increased costs, pay-back times were < 2 years and the annual rates of return were several times higher than theminimum interest rate. These results constitute a strong incentive for providing indoor air of a quality that is better than the minimum levels required by present standards.

-

-

The article is focused on a topic of ventilation in dwellings and methodology of ventilation measurements in naturally ventilated buildings. The attention is paid to a possibility of using carbon dioxide produced by people as a cheap tracer gas. This paper deals with the first part of the study, which covers the initial problem analysis and distribution of CO2 produced by people in a room without mixing fans.

The article presents common characteristics, that affect dynamics of heating systems. There are described used methods of analysis and evaluation of heat dynamics in the world.

The article describes the reconstruction of Kamenice nad Lipou castle, and namely those parts of reconstruction concerning construction and heating. The heating equipment is equipped with roof boiler room, upper distribution system and with single-pipe horizontal distribution systems for the most part.