Issue 4/2008

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Energy savings necessity and demands on providing the air quality by sufficient ventilation rate in ventilated and air conditioned rooms are contrary requirements. A new product (AirQ) for air quality and temperature control enables to bring into accord both requirements and meets as well the request on individual control in each zone. In variable air volume systems, it enables to achieve considerable energy savings. There are examples of AirQ utilization and accomplished results given in the article.

Description of a method of time course calculation of a cooling capacity in dependence on required indoor air temperature. The principle of the solution is a synthesis of a load quantity in the dynamic model. A heat nodal model comprehends relevant heat capacities and resistances. An example of a cooling capacity calculation in an air-conditioned room in a building with light siding is given. Described approach yields to the maximum capacity and energy consumption determination. The example is replenished with figures demonstrating the maximum source output dependence on different values of heat capacities included in the model.

Air-conditioning equipment is more and more fitted with different types of rotary compressors, mostly the l type. Piston compressors – namely hermetic compressors are step by step fully displaced and often are not further included in production schedule of many air-conditioning producers. The Copeland Company as a one of the biggest refrigerant compressors’ producers offers in its program of rotary l compressors several type series suitable especially for the air-conditioning equipment. Digital l with a continuous output control is an important contribution to energy savings in the air-conditioning equipment.

New possibilities of approaching the optimal and reliable evaluation of boilers operation are investigated in connection with increasing heating expenses. While the boiler efficiency quantity is obtained at exactly defined nominal boiler parameters in ideal laboratory conditions, from the standardized and annual boiler utilisation factor we expected a reflection of the real operational conditions. However, contrary to Germany and Austria, the standardized utilisation factor has not become commonly used in our country. The aim of the text is thus to draw the attention to individual evaluative parameters of boiler operation and certain difficulties of standardized utilisation factor determination including the impact of variable water flow through the boiler.

In this article, which freely reassumes another authors' article "HVAC Equipment Design for Cultural Buildings" published in VVI no.4 and 5/2007, the author apprises readers with HVAC design solution in some of the Prague theatres. The topic was a reconstruction of several theatre halls in historical and modern buildings, which naturally yielded some difficulties or even serious limitations during the ventilation equipment modernizing process. Therefore, the proposed solutions can be directions for other reconstructions design, even though each reconstruction typically requires its own inventive solution.

A system with capillary mats is one of the radiant conditioning systems without high demands on energy consumption. The capillary system can be used in almost any building for both heating and cooling. The low height of a construction with capillary system enables its broad utilization in new buildings as well as in building reconstructions. The author describes different possibilities of capillary mats utilization in practical applications and gives examples of implementation.

The author apprises professional public with an amended and extensively revised Czech technical standard. Some of the new and important changes of the design, realization and control of chimneys and flue-gas ducting, coming into force on 1st February 2008, are pointed out. The article is supplemented with a number of important pictures. The standard itself can be evaluated as a very detailed and well understandable one. This arise a prerequisite, that the new technical document can become an efficient and first-rate helper in design, realization and control process of such important construction elements, as chimneys and flue-gas ducting are.