Issue 5/2010

Author introduces an issue of solar collector measurement and significance of measured figures for thermal performance description in the form of comprehensive review. Reference areas of solar collector are exactly defined and differences in determined efficiency due to discrepant interpretation have been shown in practical example. Theoretical analysis of solar collector efficiency and power related to mean fluid temperature has been introduced. Author also concentrates on performance of solar collector under skewed beams. Analysis of collector thermal power with use of experimentally determined incidence angle modifier (IAM) has been presented.

Article deals with parallel and series connection of boilers which are sequence controlled. There are given benefits and disadvantages of both connection manners and described their sequence control behaviour for the parallel connection example.

Article summarizes the possibilities of photovoltaic panel’s installation to block of flats, presents the advantages and disadvantages of various solutions, and compares energy gain at different positioning of PV panels

The presented paper deals with energy simulation of all-year operation of a ground heat exchanger GHE, which is used as a component of a warm-air heating/ventilating system in a low-energy family house in the North-Moravian region. Using the simplified model, created in the TRNSYS program, energy and economic savings resulting from exploitation of GHE in heating and summer seasons are evaluated.

Authors focused to visualization methods for the observation of the flowing air in ventilated and heated rooms, and their article includes contact methods; i.e. the smoke method above all that is used often in practical applications, method PIV (Particle Image Velocimetry) that is used in laboratory conditions and a relatively new method using thermovision for visualization of non-isothermal air flows. They focus also to non-contact methods, amongst which belong e.g. interferometric method and a large-field schlieren method for visualization of non-isothermal air flows. Samples of visualization records, which provide valuable and qualitative information on the flow shapes, their reach and interaction with surrounding is stated in the article. Further, there are mentioned possibilities of the quantitative evaluation of acquired records supplemented with examples of acquired results. They use their own software for the evaluation of records from the smoke method and interferometry.

The need of exact control of temperature, humidity and air velocity is main reason, why the application of different simulation methods is very suitable and progressive help for designers and researchers. This paper is focused on the numerical analyse of ventilation of building for broilers during the summer with the use of computer fluid dynamics (CFD) software Fluent. There are specific problems in the buildings for broilers, because they are growing in artificial conditions since the first day of their live (several grams of the weight) to the end of fattening (several kilograms). Especially summer period with highest outside temperatures at the end of fattening period and winter period for one day chickens with low outside temperatures are problematic.

The article includes the analysis of the regularity in the progression of the speed field and the temperature field in the non-isothermal jet of the cold air alongside a vertical wall. The air comes out from the horizontal slot linear outlet with the width of 0.05 m and 0.1 m and 4 m long, adjacent to the vertical wall with a low discharge speed of 0.2 m/s and 0.4 m/s and the air temperature by 3–10 K colder than surroundings. There is shown the impact of the uplift force to the speed course in the jet.

Authors report on thermal hygienic krepiny of sediment and describe this process both theoreticaly in detail and practicaly with presentation of chart and time behaviour by actual device. They are against legislative demands to this issues substituent in last part.

The author practically assesses experiences of specialized firm during its exercising the service activities in the field of air conditioning and HVAC in his article. Originally, it was a contribution that was heard within the accompanying program of the Society of Environmental Engineering during the exhibition of AQUATHERM 2009 that took place on 27 November 2009.

The Author deals in detail with the European legislation concerning the Czech legislation in the area of the central heating of buildings and preparation of warm service water above all, in his article. He engages in directive 93/76/EHS from the area of the district heating and the directive of the European Parliament and the Council 2006/32/ES on the energy effectiveness at final users (clients) and energy services and he assesses the achievement thereof in the conditions of the Czech Republic.