Issue 2/2012

The author specifies the total cooling factor (COP) analysis of the air conditioning system in his contribution. The total cooling factor includes the specific energy demand of the cold source as well energy demands of fans and pumps that have been the part of the air conditioning system and ensure the heat load exhaustion from the required building area. The total cooling factor (COP) is one of important indicators of economy during the air conditioning equipment operation. The contribution includes the total cooling factor of the air conditioning system in two buildings in addition to the theoretic analysis the results of which have been analyzed.

First part of the contribution “Methods for Design of WSW Reservoir was published in Magazine VVI, 2011, No. 3. There were described designs of the WSW reservoir pursuant to CSN 06 0320 or DIN 4708. The second part of the contribution deals with the detailed design of theWSWreservoir pursuant to ČSN EN 15316–3. It concerns of the comprehensive and exacting issues tightly connected with the building energy demand, which cannot be pressed in the content of one contribution. Therefore, it was divided in three parts. We shall expect with interest the third, i.e. the final part of the contribution in which the author shall assess and compare individual calculation methods with the application to family and dwelling houses.

Authors describe the application of solar systems in district heating systems and problems that may appear at the solar systems and district heating systems combined operation. Further, there are specified several acceptable categories of solar systems with various levels of heat demand coverage, in their contribution. They show the technical solution of the suburban town at the example. The technical solution is elaborated in the simulation environment and economically evaluated afterwards. The solar energy in district heating systems is utilizable, however the price of heat from this source is a negative factor.

The author of this article informs readers about a design of the biomass power and heating plant for Plzeňská teplárenská (Joint Stock Company). This power and heating plant secures at least 10 MWe electricity supply.

The author concentrated results obtained from the assessment of 38 objects (premises) with arrangements concerning the reduction of the energy demand after approximately 5 to 12 years of operation, in his article. There has been elaborated a uniform methodology for result assessments enabling the comparison of obtained results and their transformation in the standardized peripheral conditions.

Condensation of water vapor in regular heat recovery heat exchangers is not an exceptional state, but its influence is usually neglected. In the article is described possible efficiency increase due to rise of transferred heat flux between cooled and heated air stream caused by latent heat from condensation of water vapor contained in air.

The author introduces readers in a very comprehensible and transparent way with requirements for thermal insulations, applied in many new European standards. He brings very useful information resulting from EN 14303 to EN 14309, EN 14313 and EN 14314. At the same time, the author draws the attention to the fact that the existing practice of assessing pursuant to the Construction and Technical Certificates shall terminate after the transient period of time and the certification shall proceed upon the basis of new harmonized standards, only.

The article deals with calculation the economic thickness of heat insulation for plane walls and pipes. There is published the procedure to determine a magnification influence of the thermal insulation thickness for an economic thickness. The article does not deal with building thermal insulation. The calculation of the economic thickness of heat insulation concerns processing equipments, cooling boxes, storage tanks and technological pipes.