DAYSIM

DAYSIM logo.

Free RADIANCE-based daylighting analysis software to predict the annual daylight availability and electric lighting use in arbitrary buildings for manual and automated lighting and blind controls. Screen Shots

Keywords

annual daylight simulations, electric lighting energy use, lighting controls

Validation/Testing

DAYSIM is based on LBNL�s validated RADIANCE software. A validation study of DAYSIM has been published under: Reinhart C F, Walkenhorst O, �Dynamic RADIANCE-based daylight simulations for a full-scale test office with outer venetian blinds.� Energy & Buildings, 33:7 pp. 683-697, 2001.

Expertise Required

DAYSIM is ideal for individuals who have experience using RADIANCE as it uses the same input files. For those who currently lack this expertise, the Lightswitch Wizard is a lighter online version of DAYSIM that allows to analyze sidelit peripheral offices.

Users

Between Mar 2002 and Nov 2003 over 330 individuals from more than 120 A & E firms and 95 research institutions downloaded the DAYSIM software.

Audience

Building designers to design buildings with �enough but not too much� annual daylight; lighting designers to assess the energy/cost benefits of lighting and window blinds controls.

Input

RADIANCE building scene files, a RADIANCE sensor point grid file, and EnergyPlus weather data.

Output

  • annual illuminance/luminance profile due to daylight at investigated sensor points
  • daylight autonomy distribution
  • daylight factor distribution
  • annual electric lighting energy use for different lighting control systems

Computer Platform

Windows 95, 98, 2000, and XP as well as Linux/Unix operating systems.

Programming Language

JAVA, C

Strengths

DAYSIM is the first program that provides reliable predictions of lighting energy use in offices by considering occupant control of lighting and blinds. The underlying user behavior model is based on field study data. The tool should be used to estimate the energy saving potential of automated compared to manual lighting controls. Annual daylight availability predictions are very accurate since they are based on RADIANCE simulations. The program comes with a tutorial and detailed online help functions.

Weaknesses

Since DAYSIM is based on RADIANCE, it requires the same amount of knowledge of how to properly set the RADIANCE simulation parameters.

Contact

Company:

National Research Council Canada

Address:

Institute for Research in Construction
1200 Montreal Road M24
Ottawa, Ontario K2P 0Z4
Canada

Telephone:

+1 (613) 993-9703

Facsimile:

+1 (613) 954-3733

E-mail:

christoph.reinhart@nrc-cnrc.gc.ca

Website:

http://www.daysim.com

Availability

DAYSIM can be downloaded at no charge from www.daysim.com. User manuals and detailed tutorial come with the download.