analysis of the influences of solar radiation and façade glazing ...

4.1 Summary 100
and determine the most important factors, especially solar radiation, affecting energy
consumption was carried out.
Special attention was focused on the heat transfer through windows. One of the main goals
of the current work was the determination and comparison of the gain and loss of thermal
energy through the building fenestration. Glazed openings are very important elements in
building design. Windows provide natural day-light into rooms to reduce the use of electric
lights and allow heat gain from solar radiation. The type of glazing materials used in a
building construction makes a significant contribution to the annual energy consumption.
For this reason, it was decided to examine twelve cases of fenestration products with
different types of low-e coatings and different configurations of optical filters on a glass
surface. The parameters of the developed glazing systems such as visible transmittances,
U-factor, solar heat gain and shading coefficients were determined with help of the
computer program WINDOW 5.2. The simulation results as indexes of building energy
consumption, heating and cooling energy demand were used to select the optimal window
performance. Combinations of thermal and optical properties of the recommended glazing
system should provide low energy consumption throughout the winter months due to the
highest passive solar transmission.
Large areas of glazing in each facade of the developed buildings may result both in the
increase of heat losses in winter and the deterioration of thermal comfort conditions for the
occupants by overheating during the summer. So, that is why the optimization procedure
was presented and an optimal value of window-to-wall ratio that leads to a minimum
energy consumption for space heating was determined.
The current work reports energy balance of glazing system for north, south, west and east
face of the developed building. Simulations were conducted for the following five
locations in Germany: Hannover, Berlin, Düsseldorf, Frankfurt and Hamburg with
different weather conditions.
The variability of passive solar gains connected to the windows height above the ground
level for heating and warm periods separately was the next problem resolved by the author.
The research results concerning an analysis of the thermal environment in the living
apartments during the warm period were presented as well. The building indoor
environment was described by using an operative temperature and a PMV index.
A reduction of gains from solar radiation during the summer was performed by different
combinations of protection shields made by movable glass parts printed with various
patterns and internal alternatively external window shades with highly reflective
parameters. In order to reduce the internal air temperature, we used intensive mechanical
ventilation when the outdoor temperature was lower than the air temperature in rooms. The
next series of calculations were performed to investigate how variable air volume system
influences the thermal environment in living spaces.