Article published in Journal of Automation in Construction about “assessing the energy and daylighting impacts of human behavior with window shades”

Capture.JPG

Abstract

Manual and automated blind controls are typically not included in energy and daylight simulation in part because there is no consensus in the research or practice communities about the way users operate manual blinds or override automated blinds. In order for blind use patterns to become part of energy and daylight simulation best practices, the range of annual energy and daylighting impacts associated with blind use must be understood. This paper addresses these aspects by comparing four leading candidates of manually-controlled blinds plus two automated blind control algorithms using a high-rise office building located in Boise, ID. This study revealed that all four current “manual” blind use algorithm choices perform relatively similarly to automated systems, and surprisingly sometimes even more efficiently. LM-83 currently has the lowest average occlusion during regularly occupied hours, followed by Lightswitch-2002, while Blindswith-A and -B have the highest average occlusion. The IES-recommended manual blind algorithm resulted even in lower average blind occlusion and lighting energy consumption than automated systems. Finally, life-cycle cost analysis was calculated. The results show that the cost savings from interior automated shading system are substantial over a 30-year time horizon, when compared with common passive manual blinds ($25 versus $7.6 Net Present Value per SF glazing area).

Highlights

  • Annual energy and daylight impacts of six manual and automated blind algorithms are provided.
  • Manual blind use patterns have considerable impact on energy end-use consumption.
  • Current “manual” blind use algorithm choices perform relatively similar to automated systems.
  • Current manual blind use algorithms are not adequately representative of actual user behavior.
  • Cost savings from interior automated shading system are substantial over 30-year time horizon.

Keywords

Manual blind use
Automated blind operation
LM-83
Lightswitch
Blindswitch
Spatial daylight autonomy
Annual sunlight exposure
Life-cycle analysis

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s