Lighting Commentary: Adjustment of Perspective

 

While achieving the lighting conditions necessary to qualify for the Commercial Buildings Deduction can be related to good practice and available technology, working with the Deduction can require some adjustment of perspective.

Many lighting practitioners who perform retrofit services are used to thinking in terms of achieving desirable payback and return on investment numbers based on an existing system. While these numbers are important to the owner, the Commercial Buildings Deduction does not recognize their relevance.

For the purposes of qualifying for the deduction, the lighting practitioner must focus on achieving savings targets below ASHRAE/IES Standard 90.1-2001, which is the standard to beat, and otherwise complying with certain requirements of the Standard—such as the upgrades must be permanently installed, etc.

In addition, the savings target is based on exceeding the minimum requirements of Standard 90.1-2001’s interior lighting power allowances, but the controls provisions must also be met. Bi-level switching, while not required by the Standard, must also be installed in all occupancies, with few exceptions, and minimum light levels established by the Illuminating Engineering Society of North America (IESNA) and published in the 9th Edition of the IES Handbook must be achieved so that the users of the space will have minimum recommended light levels for performing their tasks efficiently, accurately and safely.

 

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