Energy and comfort control for building management systems
Project leader: Nicolas Morel
Project participants (EPFL): David Lindeloef
Project participants (external):
Fraunhofer Institute for Solar Energy Systems, (Freiburg, D, coordinator at the European level), DBUR (Copenhagen, DK), Ingélux (Lyon, F), Hüppelux (Oldenburg, D), Technoteam (D), Bug Alu-Technik (A), Servodan (DK)
Duration and funding: November 2002 to February 2006, funding by Swiss Federal Office of Education and Science
The objective is to develop a new generation of control devices for solar shading, glare control, electric lighting and HVAC systems for the simultaneous optimisation of building energy consumption and comfort: they can considerably reduce the peak cooling load and the total annual building energy consumption. Another goal is the development of glare criteria for windows and daylighting systems, which can be used for control purposes and the development of a new multipoints luminancemeter. A design tool will be developed to predict the energy impact of different control strategies. It will contain a rating scheme for visually and/or thermally uncomfortable situations.
The work is split into 7 work packages with a number of subtasks: Coordination (WP1), User assessment (WP2, develop new criteria for glare rating to be used as input for building management systems), Measurement facility (WP3, design and construct a device for luminance measurements), Control device (WP4, develop new control algorithms and construct a prototype controller), Design tool (WP5, develop an information package for building planners and scientific software tools), Pilot buildings (WP6, test the algorithms developed in occupied multi-room buildings) and Dissemination (WP7, transfer results to scientists, standardisation bodies, component and facade manufacturers, architects and building planners).
The project has been extended until end of February 2006, but is nevertheless suffering an important delay. The most important work packages of the project are summarized below:
- User assessment (WP2) gives interesting results. Numerous measurements with a double test cell (one test cell for the test person, one test cell with measuring sensors, both cells being submitted to exactly the same conditions) have been carried out, both in Germany and in Denmark, with various position of the person relative to the window, and with various window size and solar protection types. It has been shown that the vertical illuminance in the eye plane can be considered as an adequate index for glare assessment.
- For the control algorithm (WP4), an original control scheme has been used, based on the use of a Bayesian probability estimator for adapting the control parameters to the user preferences, and a cost function taking into account several inconveniences to minimize (energy consumption, thermal discomfort, visual discomfort when user is present, and outside view loss due to solar protection when user is present).
- For the experimental tests (WP6), unfortunately only short operational tests will be possible until the end of the project; the tests are carried out on the LESO building, on a building of the ISE/Freiburg, and on a building of the DBUR/Copenhagen. The long term energy savings will be assessed through simulation instead of measurements. For that aim, a simulation tool, based on Matlab/Simulink and connected with the real implementation of the controller, is used.