Hybrid ventilation - Development of design methods and control strategies. Phase 3
This project is phase 3 of the Danish contribution to the international project IEA-ECBCS Annex 35: HybVent - Control Strategies for Hybrid Ventilation in New and Retrofitted Office Buildings.
Design of energy-efficient ventilation systems in office buildings is often turned into a question of using either natural ventilation and passive cooling or mechanical ventilation and cooling. This prevents a widespread use of sustainable technologies because a certain performance cannot be guaranteed under all conditions. In fact in the large majority of the cases a combination of systems would be beneficial depending on outdoor climate, building design, building use, and the main purpose of the ventilation system. Suitable design tools are not available for sustainable ventilation systems as it is the case with mechanical systems. Valid design tools would give architects and engineers the necessary confidence in system performance which in many cases is the decisive factor for choice of system design. The present project is the third phase of the Danish contribution to IEA ECB and CS Annex 35 HybVent - Control Strategies for Hybrid Ventilation in New and Retrofitted Office Buildings, which will be carried out from 1/8-1998 to 31/7-2002. Annex 35 will have the Department of Building Technology and Structural Engineering, Aalborg University, as Operating Agent. The research project aims at a better knowledge of the use of sustainable ventilation technologies and is focusing on development of control strategies and design tools for hybrid ventilation in new and retrofitted office buildings and promotion of energy and cost-effective hybrid ventilation systems in office and educational buildings. Hybrid ventilation is ventilation systems where mechanical and natural forces are combined in the ventilation of buildings. Control strategies are ways to control hybrid ventilation dependent on building design, internal loads, natural driving forces, outdoor conditions and season to fulfil the immediate demands to the indoor environment in the most energy-efficient manner. The project approach includes in the third phase an analysis of hybrid ventilation control strategies with focus on both IAQ and night cooling. It also includes monitoring of the B&O headquarters building of both short term indoor climate measurements and long term measurements of the energy consumption. Finally, a guide for hybrid ventilation will be produced. Information about Annex 35 can be found in the web-site http://hybvent.civil.auc.dk
Annex 35 started with a one year preparation phase August 1, 1997, followed by a four year working phase from August 1, 1998 to July 31, 2002. the project objective is to promote the application of hybrid ventilation in office buildings in Denmark, to improve existing design methods, to develop a new probabilistic analysis method for prediction of potential and capacity of hybrid ventilation on a yearly basis, and to develop control principles and strategies for hybrid ventilation in office buildings, which ensure optimal use of natural driving forces and which at the same time ensure fulfillment of indoor air quality demands, thermal comfort demands and energy and environmental demands. The project is divided in a number of parts, each with a specific objective. Phase 3 contains the following parts: Development of control strategies and principles for hybrid ventilation in office buildings, which has focused on development of principles and strategies for fan-assisted natural ventilation. The results are described in the publication: 'Hybrid ventilation i kontorer og institutioner', which is published by By og Byg in 2004; Demonstration of hybrid ventilation performance in office buildings in Denmark, where energy consumption and indoor climate has been investigated for a whole year in an office bilding. The result shows a very good indoor climate. However, the energy consumption for heating is at the level of the requirements in the Danish Building Regulations (BR95). The results shows, that it is impossible to separate the performance of the hybrid ventilation system and the building, because of the integration of the systems; Guidebook on hybrid ventilation in office buildings, which based onthe results of the international project Annex 35, focuses on the specific conditions in Denmark. The book contains the following subjects: Description on the basis for application of hybrid ventilation, description of suitable system solutions and -characteristics for Danish conditions, calculation methods for air flow rates, pressure levels and stability, description of hybrid ventilnation components, description of suitable control strategies as well as description of a number of relevant case studies. The guidebook will be published by By og Byg in 2004
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| By og Byg | ||
| ESBENSEN RÅDGIVENDE INGENIØRER A/S |
Contact
Sohngårdsholmsvej 57
DK-9000 Aalborg, Denmark
Heiselberg, Per (lektor), 96358080, ph@civil.auc.dk
Øvr. Partnere: By og Byg (Statens Byggeforskningsinstitut); Esbensen Rådgivende Ingeniører
