Issue 2/2008

In the article the basic data are summed up about temperature conditions and heat requirements for heating in heating periods 2000/01 up to 2006/07 in Prague – Karlov. The order evaluation of their energy demandingness is completed by data about the course and extremes of selected meteorological elements influencing the final heat consumption and putting the finishing touches to the character of each period.

In the comprehensive article the author deals with new trends at air conditioning and heating systems designing leading necessarily to non-traditional solutions. The main aim of the GreenWay programme is the economic and ecological operating of buildings at minimum energy consumption, on condition that the optimum microclimate conditions were attained. The author further indicates the main items of the GreenWay programme and explains in detail the programme utilization for the concrete administrative building.

The author continues the article dealing with sound transmission of circular cross-section ducts manufactured of relatively thin sheet metal. The noise generated from duct systems surfaces, where the high level of acoustic pressure is caused first of all by the high acoustic output of fans, or frequently by noise related to gases combustion at combustion equipment, is very frequently left out on the ground of the unfamiliarity with the mechanism of its radiation. The article deals with cases when the duct of rectangular cross-section was manufactured of steel sheet.

An investigation of outer boundary conditions of ventilation was carried out using wind tunnel with atmospheric boundary layer simulation. Dilution factor of ventilation system was obtained for four typical positions of inlet and outlet with two values of outgoing air momentum. Time records of concentration were evaluated to mean values and variances expressed in dimensionless shape as a function of wind angle for single main building and the same supplemented by outbuilding.

Thermal comfort of persons working in buildings is the basic requirement of the building and ventilation, heating and eventually air conditioning systems design. With regard to the individual thermal comfort perceiving its objective assessment is relatively difficult. The design of the common air conditioning systems insists on the thermal comfort assessment resulting from human activity. However some research works advert to human ability to cope with changes of outside conditions. The adaptive thermal comfort model, which is suitable first of all for passive and low energy buildings, results from this principle.

The article deals with zinc emissions reducing at heat zinc coating technology. Emission limit according to Atmosphere protection law and expected tighter limit are satisfied, according to measuring executed by authors, by the use of textile filters with quality textile.

-

-

Standard chiller and chiller with ice storage are discussed and energy and economical comparison of both systems is carried out on a real plant.

The paper deals with a new approach, which eliminates moisture accumulation in cold pipe insulation by using of the wick-concept insulation. It is based on capillary suction of a fibre fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket the water will evaporate to the ambient air. This will prevent long termaccumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance during the whole durability of insulation. Experiments proved that the wick-concept insulation works for pipes with temperature above 0 °C and for ambient conditions within common ranges for industrial applications.

The article describes the communication possibilities of the present regulation components accessible on the market and Ethernet nets connection. It indicates what kinds of ways enable to solve the technology net accouplement to distribution frames in the building and it illustrates these ways on some examples. The contributions and hazards of individual models are described namely both from the point of view of the user and from the point of view of implementation and service firms, first of all as far as concerns safety, system function and investment and operation costs. Not even experience from implemented actions is missing in the article.