Rastislav Menďan

The Influence of Thermal Bridges on the Energy Need for Heating after Renewal: A Case Study

The contribution deals with the influence of additional heat loss caused by thermal bridges of a building on the energy need for heating. Calculations and comparisons were carried out for a simple characteristic family house built in the sixties in the last century. The family house was evaluated in original state and in four variants of a renewal.

Renewal of Envelope Constructions of Panel Residential Houses as a Tool for Elimination of Hygienic Problems of Thermal Bridges

In a general sense, it is possible to say, that panel houses show considerable defects. Many of them results from insufficient thermal protection. At present, these buildings fail to meet the requirements from the point of view of neither thermal insulation properties nor hygienic criterion (Slovak Standard STN 73 0540-2:2012). This shortcoming manifests itself not only in large consumption of heat for space heating, but also in functional and hygienic shortcomings of envelope constructions (formation of moulds). The paper deals with a thermal technical analysis of selected critical details (thermal bridges) of envelope constructions of panel residential houses in original state and in state after adding thermal insulation.

Optimal Localisation of Window in External Wall of Different Material and Construction Design Considering Linear Loss Coefficient

The goal of the article is contribution to the topics analysing the optimal window position in external wall in order to get minimal value of linear loss coefficient.

Analysis of the Influence of Thermal Characteristics of Simple Family House on Heat Use for Heating

The contribution shows an application of results of previous research regarding new method for more exact calculation of increase of thermal transmittance due to thermal bridges (ΔU-value) on a simple family house. The calculations and evaluations of thermal properties were carried out on ten variants of the selected simple family house.

New Calculation Method for Determination of the Influence of Thermal Bridges on a Building

The contribution presents a new calculation method for more exact determination of increase of thermal transmittance due to thermal bridges ΔU. Since each building is three-dimensional, to get the objective and exact results, the calculation of heat losses of a building should be carried out using three-dimensional model. However, the 3D calculation is practically rather difficult and very hard realizable in building practice in Slovakia nowadays. It is much simpler to model and calculate a building as two-dimensional. The calculation method presented in this contribution is based on the modeling two-dimensional sections of the whole building taking into account the building as a whole.

Modification of Watters’ Formula for Simple Aerated Concrete Walls

The contribution presents a mathematical modification of Watters’ formula used in modified Watters’ method. This formula expresses a dependence of sound reduction index on surface mass (mass law). On the basis of the previous research which resulted in the finding that the Watters’ method do not give acceptable results for simple walls from aerated concrete, the mentioned formula was modified to be usable for theoretical determination of sound reduction index of simple aerated concrete walls. The contribution also presents a modification of this formula for calculation of sound reduction index of simple aerated concrete walls with a plaster on both sides.

Theoretical Determination of Sound Reduction Index of Simple Walls on Various Material Bases

The contribution deals with a comparison of measured and calculated values of sound reduction index R (dB) and weighted sound reduction index Rw (dB) of simple walls from various materials. In this way it verifies the exactness of a modified calculation-graphic method according to Watters and an appropriateness of its application for simple walls from various materials with the focus on the aerated concrete walls.

An Optimal Window Position in External Walls, of Different Materials and Construction Designs, in Relation to Critical Surface Temperature

In article analysis of optimal window position in external wall of different properties is provided, considering the highest surface temperature in contact area of window and its reveal.

Thermotechnical Properties of Unburnt Clay Wall in Historical Family House and Wall Reconstruction

Article describes the problem of heat cladding in family houses built from unburnt clay, that do not represent listed buildings and had already undergone various reconstructions (restorations). Presented are measurements of basic thermotechnical properties of clay wall in historical family house and analysed is fragment of clay wall in its original condition and after renovation, considering building heat engineering requirements.

The Influence of the Position of Windows on ΔU Value

The paper deals with the analysis of the influence of the position of windows on a value of increase of transmission heat loss coefficient because of thermal bridges (ΔU value) which contributes to total heat loss of the building. The calculation of exact ΔU value was realized using a new calculation method according to Menďan [1]. The calculation was carried out on a selected residential house with thermal insulation placed on external side of the external walls. The house was solved in three variants. The variants differed in position of the windows (i.e. in the middle of the wall thickness, aligned with the internal edge of thermal insulation and the position of the windows in thermal insulation). Each of the variants was calculated for seven various values of thermal resistance of the external wall.