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 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.
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.
The objective of PV-cooling project was to develop low electricity consumption cooling systems for dwellings and office building, powered through photovoltaic (PV) electricity. Two systems have been developed, one using PV and evaporative air-cooling, the other using PV and ground cooling through buried pipes.
Three flow regimes encountered in hybrid ventilation systems, depending on the external temperature along with the imposed heating and cooling loads, are investigated . A theoretical model is used and small-scale laboratory experiments are visualised. The transitions between those naturally ventilated flows may vary according the seasons.
The aim of this study was to define whether energy savings and comfortable conditions are achievable along with a reduction or even suppression of the mechanical cooling systems.Three different cooling systems (mechanical standard air conditioning, hybrid cooling, mechanical ventilation cooling) were simulated for a typical US office space under 40 different US climatic data, to calculate energy consumptions.
The coupled thermal/airflow simulation software CONTAM97R was used to evaluate the performance of a naturally ventilated office building recently build in Entschede (The Netherlands), for which detailed measurements results within the Natvent project had already been published.
Tests have been performed on several ceiling air diffusers supplied with low air temperatures (6 to 16°C - 90% humidity) to study water vapour condensation on diffusers surface. Results show that a supply air temperature of 11°C avoids most of condensatio
The subject of this study is the design of cooled ceiling and displacement ventilation systems in buildings. States that good design of CC/DV systems can lead to better indoor air quality and thermal comfort in comparison to widely used VAV mixing systems. A key design parameter is the cooling load removed by the displacement ventilation. Due to a small vertical temperature gradient, a low DV has a positive effect on thermal comfort, but also has a negative effect on indoor air quality because of the increased mixing of room air.
Proposes an HVAC system which combines chilled ceiling with desiccant cooling, to be used in hot and humid climates where air dehumidification is necessary in order to maintain the indoor air humidity within a comfort zone and to lessen the risk of condensation on chilled panels. The system decouples temperature and humidity control by using desiccant wheel for moisture removal and ceiling panels to control the temperature. Another three systems were viewed to evaluate the system performance and energy savings potential.