ASHRAE Journal - August 2012 - 50

24-hour uses and spaces where automatic shutoff would endanger the safety or security of the room or occupants. This can be controlled based on time of day, occupancy sensors, or other control or alarm systems that indicate an area is unoccupied. This provision and those in Chapter 10 were included because it will be difficult to get close to the national goal of net zero if we don’t control the plug and equipment loads.

Lighting Requirements (Chapter 9)

The lighting power density (LPD) tables were adjusted. On average, the allowable lighting power densities dropped by about 10%. For healthcare facilities, the allowance for clinics dropped from 1 W/ft2 to 0.87 W/ft2 (10.7 W/m2 to 9.3 W/m2). For hospitals, it rose from 1.20 W/ft2 to 1.21 W/ft2 (12.9 W/m2 to 13 W/m2). The room geometry adjustment is a new provision that helps when designing lighting for spaces with unusual proportions and spaces with high ceilings such as those encountered when renovating older buildings. The LPD can be adjusted for individual spaces when the room cavity ratio (RCR) for the empty room is greater than the RCR threshold for that space type as shown in Table 9.6.1. Many addenda addressed lighting controls. The committee’s approach was that the lighting power densities Other Equipment (Chapter 10) have been reduced nearly as much as Domestic water booster systems possible, and the route to increased are now prohibited from including savings is to turn more lights off pressure reducing valves through or reduce the power used for lightwhich all of their discharge water ing when they aren’t needed or less passes. This does not prohibit using light is sufficient. This will result in PRVs in zones or individual floors, a significant increase in the number but does prohibit pumping all of the of occupancy and vacancy sensing water to a high pressure and then rePhoto 1: Installation of geothermal pond heat exdevices. ducing it at the booster pump. changer for a new hospital. A requirement for third-party funcBooster pump systems must also tional testing of these devices was added with the intent that include a pressure sensor to start and/or control their speed. owners are less likely to override controls if they function The sensor must be mounted remotely in the system, or logic properly. must be included in the package that senses flow and simuPrior to 2010, Standard 90.1 did not address daylighting. In lates a remote sensor input. When there is no domestic water the 2010 Standard, four addenda address daylighting and the demand, booster pumps must automatically stop. associated lighting controls. Daylighting includes windows Elevator lighting systems are required to have a minimum and overhead light from skylights and roof monitors. efficacy of 35 lumens/W. This can be averaged among the Parking garage lighting control is now specifically addressed fixtures so, for example, two T-8 lamps could be paired with and requires a 30% minimum automatic lighting power reduc- 4 MR (multifaceted reflector) lamps, as long as the total lution when no activity is detected for no more than 30 minutes. mens divided by the total input Watts equals 35 or greater. Lighting must be controlled in daylight transition zones (enElevator fans and lights must automatically shut off if the trances and exits) so that the lighting is on during daylight hours elevator is unused for over 15 minutes. This requirement was and turned off at sunset. Daylighting control of luminaires with- added because many elevators run their fans and lights 24/7. in 20 ft (6 m) of any perimeter wall structure with at least 40% net opening-to-wall ratio is also a requirement. Options for Additional Savings Exterior lighting was divided into five categories (undevelFor facilities up to 90,000 ft2 (8361 m2), the Advanced Enoped and developed areas in national and state parks and rural ergy Design Guide for Small Hospitals and Healthcare Faciliareas, residential and mixed used residential areas, other, and ties3 and the Advanced Energy Design Guide for Large Hosmajor metropolitan areas) with different lighting power allow- pitals provide additional guidance. The overall savings for ances for each. A requirement was added for exterior lights to small health-care facilities are similar to 90.1-2010. The large
50 ASHRAE Journal ashrae.org August 2012

be controlled by either astronomical timers or daylight sensors to shut off the lighting when sufficient daylight is available; and façade and landscape lighting between midnight or business closing, whichever is later, and 6 a.m. or business opening, whichever is earlier. Other exterior lighting, including signage, must be controlled to reduce power use by at least 30% from one hour after midnight and 6 a.m. or when businesses are closed and during any period when no activity is detected for no longer than 15 minutes. Whole-building shutoff (sweep) is now required for most buildings, with two of the exemptions being lighting in spaces where patient care is rendered and lighting required for 24hour operation. Internally illuminated exit sign power is limited to 5 W per face according to U.S. federal standards. More lighting alterations projects must now meet the lighting alteration requirements. Those that involve 10% or more of the connected lighting load in a space or an area must now meet the lighting alterations requirements. This includes lamp and ballast retrofits. Standard 90.1-2007 required compliance if 50% or more of the luminaires were replaced.

ASHRAE Journal - August 2012

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