energy performance

Over the last three years the understanding, adoption and use of BIM has gained international momentum.

This article introduces two system models to simulate the energy performance of the temperature and humidity independent control air-conditioning system (THICS) and the conventional air-conditioning system (CAS). The energy performance comparison includes three parts of cooling resource, transportation system and terminal devices. A typical office building with these two different systems is numerically analyzed. Beijing and Guangzhou, two major cities in China, are chosen, which lay in temperate zone and tropical zone respectively.

Based on the generic dynamic building energy simulation environment, EnergyPlus, the simulation model of energy recovery ventilator (ERV) is built in this paper. With different indoor temperature setpoints, the energy performance of ERV along with the availability of ERV is investigated both for Beijing and Shanghai weathers in China in terms of the ratio of heat recovery to energy supply by HVAC devices and ERV. Simulation results show that the seasonal average of the ratio is linear with indoor temperature set-points.

This paper discuss about characteristics and energy performance of personal air-conditioning system for a general multi-bed patient’s room. Two types of personal air-conditioning systems are evaluated by the laboratory experiment. Energy performance of a peri-counter FCU (a conventional) air-conditioning system is simulated by CFD to compare with that of personal systems. Compared with the conventional system, personal air-conditioning system has an advantage from the viewpoint of amenity improvement, but may consume more energy for cooling in the system.

Double-skin facade (DSF) is an additional glass skin on the outside wall of the building. In this study a mechanically ventilated and equipped with solar protections (venetian blinds) facade was studied. The airflow inside the facade as well as opening/closing degree of the blinds was controlled in order to increase annual energy performance for both heating and cooling. Numerical simulations for climatic data of Lyon (France) showed good performance of studied DSF compared to a traditional façade.

The EPBD directive (91/2002/EU) paved the way for the European Union member states to develop and apply a holistic approach on the building’s energy performance. It is documented that buildings’ energy consumption represents 40% of the total energy consumption in Europe, a significant figure when compared to the industry and transportation sector. Respectively the CO2 emissions are calculated to be around 30%.  A series of published data indicates that the uninsulated or poorly insulated roofs account for up to 25% of energy losses.

Low energy buildings, being highly insulated, are subject to important overheating risks. Thermal simulation as well as experimental studies have shown the large potential of ventilative cooling. One barrier against this approach is the difficulty of evaluating air flows. Appropriate calculation methods and characterization of openings are needed, so that these systems can be dealt with in design, regulation and certification tools.

BR10 requires that all new residential constructions should be built as low energy housing. In order to meet these requirements residential buildings must be equipped with far more complex technology, than conventional housing. This, for example, could be a combination of mechanical balanced ventilation, natural ventilation, heat pumps, solar heating, solar cells or automatic sunscreens.

Starting January 1st, 2013 the French thermal regulation will impose a minimum requirement for residential buildings air-tightness. However, nothing is planed for non-residential building, for two reasons:

This study presents some results from a monitoring project with night ventilation and earthto- air heat exchanger. Both techniques refer to air-based low-energy cooling. As these technologies are limited to specific boundary conditions (e.g. moderate summer climate, low temperatures during night, or low ground temperatures, respectively), water-based low energy cooling may be preferred in many projects. A comparison of the night-ventilated building with a ground-cooled building shows major differences in both concepts.