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.
In moderate climates, one promising feature to reduce the energy demand of office buildings for air conditioning without reducing comfort is passive cooling by night ventilation. An office building has been designed, realised and monitored for a long time period in the framework of the German research programme solar optimised buildings. The night cooling of the office building has been realised by natural ventilation.
In this work, experiments were carried out to estimate deposition rate of 5µm particles powder in large cylindrical straight ducts for different diameters. Two types of ducts were compared: rigid ducts and flexible ducts. Results are compared to theoretic
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
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.
In order to save energy for building cooling during hot days in regions with cool nights, air circulation throughout the interior of the building has been envisaged as a means to lower the temperature of the building structural mass. In this way, energy required for cooling the building interior is reduced, due to lowered temperature of the wall, ceiling and other structural elements mass, and a greater storage of heat resulting from various heat gains the following day when air-conditioning is on.
This theoretical paper studies of the interaction between air curtains system and purging dilution systems in a real urban underground railway station in order to find the best design to reduce concentration of polluting gas toward adjoining environments. Numerical computations are carried out with NIST package Fire Dynamics Simulator (FDS). The use of an approximate form of the Navier-Stokes equations for low Mach number application is appropriate. Polluted gasses flow towards safe space can be reduced of the 26-53% by operating air curtain systems.
Double skin façades may help combine a high degree of transparency with high thermal and solar performance. Advanced façades serve as filters and may be responsive to changes in environmental conditions and occupant requirements. Since the strategies for
The present paper aims to present a distant learning educational module that concerns the energy efficient integrated building design in the urban environment. The educational material of the module includes a handbook, computerized tools, examples of urban buildings, libraries on energy efficient products and materials and climatic documentation of climatic data measured in various European urban areas.
A condensing device allows to avoid condensation on cooling ceilings in rooms with humid air. It uses thermoelectric modules in contact with the cooling panels. The pumped heat is transferred into the cooling ceiling to keep its temperature above the dew point. Tests have been performed in a full-scale chamber. A set of condensing units was mounted on a standard hydraulic cooling ceiling. The control of temperature is achieved by regulating the mass flow of the water. By this method the loss of efficiency of the cooling panels is fully compensated.