At present, the problem of energy efficiency remains extremely important. Modern building technologies allow you to create houses with the minimum power consumption, using energy efficient external protections, including plastic windows. This leads to a reduction in the heat loss of the room, but there is a danger of reducing the required air exchange.


In low-energy and passive houses, about 80 % of the total energy is consumed for fresh air heating or cooling, the reason being the improved thermal insulation and air tightness of such a building. In fact, actual trend of building construction is to keep the windows closed. A similar situation is already encountered in some means of transportation, i. e. air-conditioned trains. Ventilation of the passenger space is assured mainly by a mechanical ventilation and, when the train stops, by a natural ventilation through door opening.


Replacement of old wooden windows in a new plastic windows, in the old buildings, we achieve the massive reducing heat loss of the building. New windows are characterized by better tightness. The question is, how much more are reduce the uncontrolled ventilation. In the article is presented the experimental measurement indoor air quality in the room in two phases. In the first phase is in the room installed 55 year old wood window. In the second phase is in the same room installed new plastic window.

Influence of natural and mechanical ventilation on elimination of heat load in the loft space

A purpose of this submission is a dynamic analysis of indoor environment on the suitably chosen classrooms, which are situated in the loft spaces of Civil Engineering Faculty in Kosice. The evaluation was doing by using energy simulation tool and is oriented on evaluation of heat load during summer period. The subject of analysis is to consider influence of selected mode of natural and mechanical ventilation on a modification of operative temperature in classrooms.

Analysis of ventilation rate and concentrations of carbon dioxide in the office

The aim of the article is to establish the necessary air exchange rate in the room at the principal production carbon dioxide calculation and experiment. In order to determine the necessary volume the air flow was made more experimental measurements in selected rooms. From the measured data of concentration CO2 by combination of graphic method and mathematical formulas we can determinate the required air flow which meets the hygiene requirements. The entire computation we can see on the example.

Ventilation and indoor air quality in the classroom

his paper highlights the importance of environmental protection regarding the reduction of energy consumption while keeping the living standard. In low energy houses, up to 80 % of the total heat is consumed for the heating of fresh air for a comfortable environment. The aim of this article is to examine the effect of temperature, humidity, air velocity and concentration of carbon dioxide in regard to the human behaviour in indoor environment with natural ventilation, i.e. without a ventilation device, where ventilation is forced or an air conditioning.

Application of CFD for interior flow analysis influenced by exterior conditions

The aim of the paper is the presentation of application CFD analisys for interior flows in chimneys and flats in a building. It is a summary of a case study of fatal intoxication by carbon monoxide coming from a gas heater of flowing water at a bathroom. That kind of accidents mostly happens due to problems with ventilation and very popular old construction gas water heaters. Closed, airtight windows are the main causes of the production of carbon monoxide but sometimes wrong construction of the chimney outlets versus the roof shape causes the backdraught of combustion products.