The applicability of natural ventilation depends strongly on climate. The potential of natural ventilation represents a measure of the feasibility of natural ventilation in a specific climate. A quantitative measure of this potential, expressed in degree-hours, may be estimated based on adaptive thermal comfort and monthly mean temperature. Degree-hours for natural ventilation represent the sum of the degree-hours for cooling saved by using natural ventilation when adaptive thermal comfort is considered.
Nowadays the awareness concerning the environmental pollution and the demand of transparent facades in architecture, lead research in finding new solutions to increase the energy performances of the building and the installations as well. Among those, different kind of Double Skin Facades have been studied and several laboratories are still working on them to find a suitable way to apply this technology in buildings.
This paper considers an ideal naturally ventilated building model that allows a theoretical study of the effect of thermal mass associating with the non-linear coupling between the airflow rate and the indoor air temperature.The thermal mass number and the convective heat transfer air change parameter are suggested to account for the effect of thermal mass heat storage and convective heat transfer at the thermal mass surfaces. The new thermal mass number measures the capacity of heat storage, rather than the amount of thermal mass.
Studies on buildings have shown that airtightness and insulation increased in family buildings and detached houses too, due to new thermal regulations. In the same time, studies concerning health and indoor air quality have shown that the need of fresh air will increase too.
This paper describes the results of a collaboration study between ENTPE-LASH and LEPTAB within the framework of the IEA Annex 35 “Hybrid Ventilation in New and Retrofitted Buildings”. The aim of the work is to carry out a cross-simulation study and identi
Ventilation is one of the most important measures to dilute indoor air pollutants. In order to maintain a clean indoor air environment, not only the total ventilation rate of the building but also the distribution of outdoor air to each area must be taken into consideration. A performance evaluation of the combined system of air supply from the crawl space and hybrid exhaust ventilation with a small fan and damper has been investigated. This investigation was undertaken over a heating season using a full-scale test house.
To evaluate the impact of the natural ventilation of the air cavity in the prototype of the glazing system being studied in the frame of the project SOLVENT, funded in part by the Commission of the European Union, a prototype of a reversible naturally ventilated glazing system. The system consists of a double (clear and tinted) glazing. In the summer position the tinted glazing is in the outer position and the cavity is open to the outside air at both top and bottom extremes.
In the present communication, a psychometric model has been presented to evaluate the performance of rotary desiccant wheels based on different kind of desiccants e.g. silica gel and LiCl. The developed psychometric model is based on simple correlations between the relative humidity and enthalpy of supply and regeneration air streams. The model is used to predict the performance of three type of desiccant rotors (Type-I, II and III). The model is tested corresponding to a wide range of measurement data.
The combination of an open wet cooling tower with chilled ceilings is a CFC free, cheap and low energy cooling solution. The efficiency of this alternative to mechanical cooling is very dependent on climate. There is a need for specific tools to help designers to size the system and to estimate its energy and water consumption. A building simulation tool, called ConsoClim, has been used to predict the performance of this system for different French climatic locations, thermal inertia, internal loads and solar gains.
To evaluate innovations and efficiency as regards air-conditioning, it is necessary to know for how long and in which conditions the equipment functions, an indication related with the COOLING LOAD and which is their effectiveness - EER - on average (or Seasonal) known as SEER. We extended the concept of SEER to include all sources of electricity consumption, namely the secondary equipment, and we called this extended concept the SYSTEM SEER.