ABSTRACT Title : Occupant Comfort Relating to Lighting Strategies in the VeriFone WorldwideDistribution Center.Building Name :VeriFone Worldwide Distribution Center, Costa Mesa, CAAuthor: Swapna SundaramUniversity of California, Los AngelesSynopsis :The VeriFone Center near Los Angeles is designed for maximum daylightingfrom clerestory windows and diffusing skylights. These are integrated withfluorescent energy-efficient lighting fixtures, controlled by occupancy sensorsand photosensors..The open office area, the specific subject of analysis, is illuminated bydirect/indirect fluorescent fixtures, with daylighting provided by a deep spineclerestory. To determine illuminance levels, the study used an illuminancemeter, two Hobo Light Intensity loggers and a camera. Occupant visualcomfort was determined by the use of a questionnaire.Findings :Some of the occupants complain of glare in the mid-morning or mid-afternoon, depending on whether they sit facing the east or west. Sun-anglediagrams drawn for those times through a cross-section of the office spaceconfirmed the entry of direct beam radiation onto workstations in the springand summer.The illuminance levels are not constant across the space. The “maintained”peak level of 40fc was recorded only for office carrels enjoying both artificiallight and natural clerestory light. The carrels at the far end record much lowerpeaks of around 25fc.Other than these findings, the building is extremely pleasant visually, with anoverall highly positive reaction from the occupants. If the above problems areaddressed sensitively, the building could stand as a model of successfullighting strategies and occupant visual comfort in a predominantly industrialsetup.TABLE OF CONTENTSI. INTRODUCTION II. PERFORMANCE TOPICS AND HYPOTHESIS POSTULATIONIII. METHODSIV. RESULTSV. CONCLUSIONS APPENDIX - I CASE STUDY DOSSIER FORM APPENDIX - II SAMPLE SURVEY QUESTIONNAIREI. INTRODUCTIONOccupant Comfort Relating to Lighting Strategies in the VeriFone WorldwideDistribution Center.A. BUILDING INFORMATION AND PROJECT:VeriFone is an international corporation manufacturing electronic verification equipment. In 1991, thecompany decided to initiate a program to upgrade and expand their buildings worldwide in anenvironmentally responsible manner. The first building chosen was a 76,000 square foot tilt-up concretecommercial structure to the immediate south of its existing distribution center in Costa Mesa, SouthernCalifornia, both separated only by a shared parking lot (Fig.1). Located between the Costa Mesaairport and a busy highway, this tilt-up building had many problems, some of which were shared byits “twin”: only three roadway windows, no views, poor outside air quality, inefficient lightingsystems, minimal daylighting.VeriFone believed in combining the latest environmental technologies with sound business practices. Asa result, the company hired the prestigious environmental architectural firm of Croxton Collaborativesbased in New York as principal architects, with the local firm of Robert Borders and Associates asassociated architects on-site. The engineering firm was Newcomb Anderson and Associates from SanFrancisco. The inside of the concrete shell was completely redesigned, and new sustainable and energy-efficient features were incorporated, among which were included daylighting features and energy-Figure 1 - Building Planefficient lighting, and special double-glazed low-E glazing for skylights and clerestories. Acomputerized EMS (energy management system) controls the lighting as well as the HVAC. Thebuilding was completed in February 1993, and occupied soon after.B. CLIMATE INFORMATION:VeriFone is located in Costa Mesa, which is a small industrial community along the Pacific Coast. As aresult, the closest climate indicator would be the weather conditions for the coastal areas of LosAngeles County. The climate is normally pleasant and mild throughout the year, not only due to themoderating influence of the Pacific Ocean, but also due to the fact that north and east coastal mountainranges act as buffers against extremes of summer heat and winter cold.The average daily temperature ranges on the coast are about 15 degrees in summer and 20 degrees inwinter. The yearly maximum is approximately 75 deg.F and the yearly minimum is approximately 55deg.F. January is the coldest month, with a monthly average of 57 deg.F. August is the hottest month,with a monthly average of 75deg.F.The relative humidity is highest in the late night and early morning, with values of approximately72%. In the late morning and early evening, it may go down to 53%. Most of the rainfall comes in thewinter with nearly 85% of the annual total occurring from November through March. Summers arepractically dry. The yearly total is around 12 inches in the coastal areas. Thunderstorms are infrequent.The prevailing winds are westerly during the spring, summer and early autumn. North-easterly windspredominate the rest of the year.Low clouds are common at night and in the morning along the coast during spring and summer. Therefore,average annual cloudiness and fog frequencies are greatest near the ocean. Dense fog is more likely tooccur during the night and early morning hours of the winter months. The yearly percentage of possiblesunshine is approximately 73%, with a high of 83% in August, and a high of 70% in January.II. PERFORMANCE TOPICS AND HYPOTHESIS POSTULATIONA. SPECIFIC BUILDING PERFORMANCE TOPICS:The key strategy developed, however, in the building retrofit design was the maximum utilization ofdaylighting strategies integrated with energy-efficient fluorescent lighting fixtures. Direct andindirect beam and diffusing skylights and clerestory windows work in combination with artificialfixtures controlled by photosensors as well as occupancy sensors.B. HYPOTHESIS FORMULATION AND POSTULATION:The open office area balances natural light from a spine clerestory (Fig.2) running along its lengthwhich was designed specifically so as not to allow distracting direct sunlight onto the workstations, aswell as artificial light from a variety of direct/indirect fluorescent fixtures. The illuminance from thecombined lighting in the open office is maintained at approximately 40 footcandles through the EMS.The electric lights are controlled by occupancy sensors and photosensors. The questions arose: are thesefunctioning as intended? Is the lighting really maintained at 40fc at all