Issue 2/2010

Central air conditioning equipments, taking out heat gains merely by the air, are often designed with a partial circulation of reversing (recuperative) air. The conception that the reversal heat gain is achieved by such an action is disproved in the contribution and it is evidenced in the example that circulation is more demanding from the energy point of view than treatment of the ventilating air, only. It is stated therein that volume of circulation during a summer extreme is decided by maximally allowable under-cooling of the distributed air limited with dimensioning of outlets. Efficiencies of methods using the reverse air as concerns rotational recovery heat exchangers installed in front of and behind the exchanger, are compared in the second part of the contribution.

The average daily air temperature is insufficient for precise simulation of technology processes in many cases and hourly air temperatures are necessary. If they are not available, two methods of their derivation from published climate data are presented and discussed.

The Author engages in his article in the technical and normative conditions with respect to fire-stopping insulations for ducts, which unfortunately are not enough known and experienced in practice. He synoptically and understandably introduces the principles and rules of the said problems and describes important design details, as well. Certain critical places fire-stopping insulation systems and their assemblies are correctly emphasized.

The author compares two types of water air conditioning systems on the basis of their characteristic properties in the article. Hemutually evaluates cooling ceilings with the system equipped with fan-coil units from the viewpoint of the energy consumption and purchase costs in published analyses. The energy consumption in both systems was determined on the basis of a simple simulation model. Results indicate to the suitability of usage cooling ceilings that are generally considered to be more advantageous from the energy point of view.

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The author specifies requirements regarding the structures and products, acts and any other legal regulations in the second part of the serial on technical standards and legal relationship of such standards with the Czech Republic legislation by which they are determined. Those are, above all, represented with Act no. 22/1997 Coll., and 102/2001 Coll. He explains personal responsibility of the designer with respect to the correctness of the designed solution in the process of the pre-designing and designing preparation of the construction, in the article. Whichever material, structure or technology, designed and used in the construction must satisfy the fundamental requirements, stipulated in legal regulations. Whereas such requirements are specified in the design, the construction company, which is authorized to carry out the building, has to supply applicable certificates on conformity attached with the final approval of the building as the evidence satisfying conditions specified in the design. Author explains significance of standards with respect to designing construction structures and buildings, in which case standards shall serve above all, but not to rule, in the subsequent part of the article. Exercising legally non-biding requirements through technical standards meet this access. The relationship between legal regulations and technical standards is determined in accordance with a legal presumption that if the requirement of technical specification included in the technical standard is met, consequently there reasonably can be assumed that a fundamental safety or hygienic requirement of applicable legal regulation is met, as well.

Passive smoking causes diseases and premature death. Smoke-free indoor public spaces should be basic condition. Both health insurance companies and hospitality industry profit from such legislation – except of cigarette manufacturers.

Authors reject concerns about using economic fluorescent tubes in apartments in their article on the basis of measurements. Economic fluorescent tubes used in apartments do not present any health risk from the viewpoint of UV radiation, electromagnetic field and the mercury presence in economic bulb lamps.

The radon program information, the third decade of which is commencing this year is provided. The information campaign proposes to motivate the interest of proprietors of private buildings with respect to curative arrangements in areas with the increased risk of occurrence.

Calculation models are of great importance in designing buildings. They support our decisions and enable problem optimization. On the other hand, optimization engines are still not a standard part of software packages. This paper deals with optimization of building performance by genetic algorithms (GA). Three sample optimization problems are solved by developed GA, increasing the number of optimization objectives and thus decreasing the chance to guess the combination of input parameters leading to optimal solution. It is finally proved that optimization by GA is a method generally applicable and easy-to-implement.