ASHRAE/IES 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings is published every three years to provide states and other jurisdictions with a model commercial building energy code. The 2010 version, published November 2010, represents the most dramatic revision of the standard since 1999. In this two-part series of special reports by the Lighting Controls Association, we will examine the new energy standard in detail. Part one, presented here, focuses on changes to the prescriptive lighting power requirements as well as changes to scope and administrative requirements. Part two, to be published next month, will focus on the standard’s extensive list of new mandatory and optional lighting control requirements.

The big news is that ASHRAE 90.1-2010 has been published. It represents a major leap in evolution of the energy standard; it’s basically almost an entirely new standard. Lighting controls play a starring role. Here is a summary of lighting control-related changes that caught my eye at first glance.

Code authorities are considering approaches to energy codes that are performance based instead of mainly prescriptive. In a performance-based code, the building would be designed so that it would operate within a target limit for energy consumption—using annual kWh/sq.ft. instead of W/sq.ft. as the primary metric.

Green construction codes and standards are beginning to emerge on the national code stage. The standards go beyond energy standards such as 90.1 and the International Energy Conservation Code (IECC) to cover additional areas such as site sustainability, water efficiency, indoor environmental quality and materials and resources. The first is ASHRAE Standard 189.1, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, published by ASHRAE in January 2010 in conjunction with the USGBC and the Illuminating Engineering Society.

ASHRAE/IES 90.1 Energy-Efficient Design of New Buildings Except Low-Rise Residential Buildings was first published in 1975 and updated in 1980, 1989, 1999, 2001, 2004 and 2007. After 2001, the intention is to update the Standard every three years. Applicability: Today, most states have adopted either 90.1 or the International Energy Conservation Code (IECC) as their […]

IECC 2009 contains a number of changes impacting lighting for commercial buildings, including:

• Forced choice of compliance with entirety of IECC or 90.1
• Required circuiting for independent control of lighting in “daylight zones”
• Revision of additional retail display allowances
• Added exemptions to interior lighting wattage that must be counted for compliance
• Splitting the exterior power allowance using a system of outdoor lighting zones
• Clarifications and practical application language changes

In terms of lighting, ASHRAE 90.1-2007 clarifies the Standard’s intent and enacts several refinements but otherwise doesn’t revise the lighting power density (W/sq.ft.) limits from the 2004 version, which itself was 20-25 percent more stringent than the 1991/2001 versions.