PR2015

An advanced heat and electricity saving strategy for the regulation of hybrid ventilation systems with automatic night cooling (ventilative cooling), mechanical compressor cooling, natural ventilation and exterior solar shading by the inclusion of MPC (Model Predictive Control) has been developed in this project. The focus is on the optimization of the total energy cost (cost function) as compared to indoor climate requirements and variations in the outdoor climate. During the test period, the test persons could override the automatic control of the natural ventilation and solar shading.

According to the International Energy Agency, buildings represent over one-third of total final energy consumption. Thus, a more sustainable future begins with low energy buildings which must combine comfort and function using passive systems and new evolving technologies. Policies to reduce building energy consumption and carbon emissions have been developed worldwide during the last decades.

In recent years, as an alternative to continuous control with the use of standard analog automation signals (voltage or current), the Pulse Width Modulation (PWM) control was introduced. Although, it is often considered as the equivalent of a continuous control, in practice this continuous control strategy is not feasible with the use of simple electrothermal actuators. The paper presents the investigation results of selected electrothermal actuators operation under ON-OFF and PWM control.

Comfort and energy saving are two important concepts treated in current buildings in order to maintain a good air quality reducing the energy consumption. According to International Energy Agency (IEA) buildings represent 32% of total final energy consumption, and the need for reduction of CO2 emission leads to pay attention to the energy demand in buildings. On the other hand maintaining a good-quality environment helps to improve the productivity and effectiveness of workers.

Thermal comfort improvement at the lowest energy consumption is a key issue when dealing with sustainability in buildings. An appropriate passive design is mandatory under those circumstances. Prior to construction, simulation tools help to make designs more sustainable. However, it is recognized a gap between real performance and the predicted one. This article presents the comfort methodology applied in an office building located in the north of Spain, characterized by a continental Mediterranean climate.

The most representative typology of residential buildings of Catalonia has been simulated in TRNSYS to evaluate the impact of both infiltration and natural ventilation. The typology is a block of apartments constructed during 1950-1980. 

The transformation of the building energy sector to a highly efficient, clean, decentralised and intelligent system requires innovative technologies like microscale trigeneration and thermally activated building structures (TABS) to pave the way ahead. The combination of such technologies however presents a scientific and engineering challenge. Scientific challenge in terms of developing optimal thermo-electric load management strategies based on overall energy system analysis and an engineering challenge in terms of implementing these strategies through process planning and control.

The control of heat losses, inwards/out, in nearly zero energy buildings is of high importance. The transmission losses through the building envelope are easily reduced using larger amounts of insulation. Calculation of the impact of this action on the total energy demand of the building, is quite standard. It’s however much more difficult to determine the efficiency of actions to increase the airtightness of the building and the influence of the ventilation system.

We conducted observations of wind velocity profiles above a high-density area in Tokyo, Japan, using a Doppler LIDAR system. Obtained data of the exponent index for the power law, which is commonly used to describe the wind velocity profile, displayed diurnal variation, decreasing in the daytime, which is expected in unstable atmospheric conditions. This paper provides information on the uncertainty in the calculated ventilation airflow rate due to the use of a constant value for the exponent index.

With a tighter building envelope more minimal influences come into consideration. As how the thermal and hygrothermal properties of the materials may improve the ventilation or whether the dust distribution is altered with the new surface temperatures and flows and of course how all other new chemicals which we introduce to living environments affects the IAQ. Preferably the in situ measurement data from the filed campaigns and case studies will be defined as ST5 in Annex 68.