The ASHRAE/IES 90.1 Standard

The ASHRAE/IES 90.1 Standard

Scope

ASHRAE/IES 90.1 deals only with commercial and high-rise residential buildings. It sets minimum performance standards for building systems and components which have an impact on building energy consumption, including the building envelope, heating, ventilation and air-conditioning (HVAC) systems, and lighting. For lighting systems,the standard defines a number of basic requirements, including: minimum number of lighting controls, ballast performance, and limits on installed lighting power. This chapter concentrates on the limits on installed lighting power. Table 1 shows the current typical installed lighting power for several applications [9], and typical guideline values for the same application from the standard.* In many cases the guideline value is significantly lower than the current typical value. However, the standard values were derived, by consensus of lighting experts, from technologies that can be adopted cost-effectively, and not from "state-of-the-art" technologies; the standard stops well short of what is technically feasible. The standard does recognize that certain applications might require more power than others to effectively light the space. For example, compare the standard guidelines for "retail display" and "lobby."

Table 1. Typical current lighting power densities for various applications, and typical guideline values from the standard

Application	Current (W/ft2)	ASHRAE/IES 90.1 (W/ft2)
Office tower	2 to 4	1.50
Lobby	2 to 5	1.00
Open-plan office	3 to 4	1.90
Drafting studio	?	2.60
Boardroom	3 to 6	1.80
Parking lot	0.1 to 0.2	0.18
Shopping mall
Concourse	3.6	1.40
Retail display	6 to 10	3.10
Car showroom	2.5 to 6	2.80
Operating theatre	7	7.00

* The ASHRAE/IES standard is published in imperial units only. For that reason, the normal NRC practice of publishing in metric units has not been followed in this chapter.