English

Experimental investigations and practical experiences in Europe have proved that hydronic cooled ceilings are able to remove high cooling loads without impairing thermal comfort. As hydronic cooled ceilings cannot remove latent loads and pollutants, e.g., C02, VOCs, odors, additional ventilation has to be applied. Often, displacement ventilation is used, which is able to provide lower pollutant levels in the occupation zone than mixing flow systems, if the occupants are causing most of the pollution.

An environmental chamber has been used to compare the effectiveness of mixing and displacement ventilation in terms of heat and contaminant removal. Results are presented for CFD simulations of the air movement in the chamber and for measurements using a heated mannequin with displacement ventilation. The CFD simulations and the measurements suggest that displacement ventilation is more energy efficient than a mixing system.

A new method for compensating the space discretization error introduced when the fixed flow field is considered for the dynamic models of temperature distribution is presented. It is proved that the method generally used in literature is a particular solution of the proposed one. Moreover, it results in a continuous-time model, for which the integrating method becomes a free choice and a state-space representation is possible.

This study focuses on the way to apply CEN test methods to a full range of air diffusers and is dedicated to the improvement of these methods proposed by the CEN TC l 56/WG4 of which both authors are members. Air terminals of different sizes have been tested on aerodynamic and acoustic aspects both in a Spanish and a French laboratory. The tests were made according to pr EN 12238 ''Air Terminal devices - Aerodynamic testing and rating for mixed flow applications" and to EN 25135 (ISO 5135).

General Dynamics Armament Systems was looking for a way to improve the performance of the ventilation system in their Lakeside Avenue industrial plant in Burlington, Vermont. By utilising adjustable speed drives (ASDs) and making other modifications to the system, they were able to improve the plant's overall operating efficiency, reduce costs, and improve the work environment and worker health and safety. This Motor Challenge Showcase Demonstration Project has resulted in annual savings of more than USD 68, 000, with a payback of just under one and a half years.

The Advanced House represents the next generation of energy-efficient housing. The total energy requirements of the house have been reduced to an estimated 31 % of the needs of a conventional home. This has been accomplished by incorporating such features, as a prototype, an Integrated Mechanical System (IMS), high-performance windows, energy-efficient lighting and appliances, high levels of insulation, airtight construction, and an energy-efficient fireplace.