VC

New buildings have to satisfy ever-tightening standards regarding energy efficiency and consumption. This results in higher insulation levels and lower air leakages that reduce heating demands. However, even at moderate outdoor temperatures these buildings are easily warmed up to such a degree that in order to ensure acceptable indoor environment quality, removal of excess heat becomes unavoidable. Use of electric energy related to mechanical cooling is considered incompatible with achieving zero energy buildings (ZEB).

The purpose of this paper is to enhance the importance of ventilation regarding energy use and stablishing methods in order to obtain as much data as possible about the behavior patterns of ventilation and infiltration in buildings.

Using solar heat energy has been paid attention to as effective natural energy use. In this study, we deal with air-based solar heat system, which is used for not only ventilation but heating and hot water supply by hot air.

Open joint ventilated façade (OJVF) is a passive constructive system widely used to ameliorate envelop of buildings, improving their energy efficiency. A laboratory model of a ventilated façade with horizontal and vertical open joints was used to study thermal and fluid-dynamic behaviour of this system. Experimental Stereo Particle Image Velocimetry (Stereo-PIV 2D-3C) was applied to study the fluid dynamic performance of this model. In addition, thermal analyses were performed applying infrared thermography and air temperature monitoring inside the ventilated cavity.

Typical heat sources in indoor environments include humans, electrical devices, and computers. The number of such sources in operating room environments is even higher due to the presence of surgical staff members and medical equipment. The exchange of thermal energy between indoor surfaces and air is usually modelled by considering contributions from both radiation and convection. Complete heat transfer simulations in indoor environments are normally difficult since radiation models have a tendency to generate numerical instability and, hence, problems with convergent solutions.

Lecture rooms with their high, quickly fluctuating internal gains, e.g. changing from no occupation to full occupation within some minutes, are quite challenging when good indoor air-quality and thermal comfort is required in an extremely low energy building context.
One essential aspect is the perfect control of air flow and temperature based on reliable, continuous measurement in all relevant parts of the ventilation system.

Aim of this work has been to determine the effectiveness of evaporative cooling and ventilation control strategies on a case study to ensure an adequate combination between energy efficiency and high levels of indoor comfort.
The case study has been a kindergarten, situated in the context of the climate continental Mediterranean area (Cerignola, Italy, 41°16'00"N, 15°54'00"E, 120 m asl), oriented on an east/west axis, classrooms south faced, and the services zone to north.

Natural ventilation is increasingly considered one of the most efficient passive solutions to improve thermal comfort in buildings. However in order to support its planning and implementation, quantitative analysis on airflow paths and heat-airflow building interactions are needed. This requires an adequate accounting of both internal effects, from building layout and structure, and external forcings from atmospheric factors.
This paper has dealt to analyze the potential of building automation systems for ventilative cooling of residential buildings.

This work presents the thermal behavior of a stand-alone experimental solar chimney during one year. The dimensions of the solar chimney are 5.60 m high, 1.0 m width, and 0.52 m depth. The absorber plate is made of a common reinforced concrete wall of 4.5 m high, 1.0 m width and 0.15 m depth. This system was designed and constructed in 2003, and it is located in the “Laboratorio de Ensayos Energéticos para Componentes de la Edificación (LECE)” at the “Plataforma Solar de Almería (PSA)” in Spain.

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.