A classroom 80’x60’ with a 11’ ceiling will be illuminated
for reading and transcribing handwriting in ink or medium pencil on
good-quality paper. Uniform lighting is required throughout the room. Desks in
the classroom are 3’ high. All ceilings and walls are to be painted medium-color
and soft 40 watt fluorescent lamps are selected for long-term eye comfort, 2-lamp-and-4’-long
luminaries are used, luminaries are to be ceiling mounted, and all luminaries
are to be cleaned every six months.
1) determine the numbers of lamps and luminaries
2) develop the light layout.
Name______________________________________________________________________ A classroom 80’x60’ with a 11’ ceiling will be illuminated for reading and transcribing handwriting in ink or medium pencil on good-quality paper. Uniform lighting is required throughout the room. Desks in the classroom are 3’ high. All ceilings and walls are to be painted medium-color and soft 40 watt fluorescent lamps are selected for long-term eye comfort, 2-lamp-and-4’-long luminaries are used, luminaries are to be ceiling mounted, and all luminaries are to be cleaned every six months. 1) determine the numbers of lamps and luminaries 2) develop the light layout. PAGE 1 MSU, Qingzhou Xu Chapter 5 ETM 430: Operations & Facilities Management Chapter 9: Facilities Systems Qingzhou Xu 105 LC Building Auxiliary Systems of Facilities 9.1 Introduction Chapter 9 introduces what basic information and general requirements that facility planners need to provide to specific engineers and facility builders to finish building auxiliary systems for a facility. 9.2 Structural System Performance 9.2.1 Column Spacing Basic point: The design of the spacing between columns and the column distribution needs to consider the function of a facility. 9.2 Structural System Performance 9.2.1 Column Spacing The most common structural types for industrial facilities are the steel skeleton frame or reinforced concrete skeleton frame. A facility’s structure and layout should be coordinated because the column configuration will impact the layout and the layout will affect the structure design. Ultimately, the structure design needs to follow the layout that guarantees the optimal operation efficiency of a facility. For example, in a warehouse, the column spacing should be determined by the rack dimensions and the access aisles between racks. That is, the clear spacing between columns must be compatible with the storage system. Clear height is important in the planning process because lower clear height may demand a larger foot print. Higher clearance can impact racking systems and be restricted by local zoning and ordinance requirements. 9.1 Structural System Performance 9.2.2 Design for Requirement Before designing a facility, it is essential to determine how the facility is to be used. Take a warehouse for example, pallet sizes affect the dimensions of racks, and rack dimensions affect column spacing. 9.1 Structural System Performance 9.2.3 Types of Column Heavy-wall round or square tubular columns should be used in warehouses. These types of columns eliminate rodent and vermin nesting places, ensure easy maintenance and cleanliness, provide the ability to place downspouts within the columns, and minimize the effect of denting on columns. They also eliminate the corners that can pull packages from pallets. In an all concrete structure, a square column is normally preferable. Because of their rectangular shape, tube columns provide a finished edge all around. 9.1 Structural System Performance 9.2.4 Consideration of Stability The building must exhibit stability under the following various loads: Dead load: Continuous, dead loads, such as roofs and floors Live load: Intermittent, live loads, such as snow, equipment and people Wind Seismic activities 9.3 Enclosure Systems The enclosure system provides a barrier against the effects of extreme cold or hot, lateral forces (wind), water, and undesirable entries (animals, insects). The enclosure elements are floor, walls and roof. 9.3 Enclosure Systems 9.3.1 Thermal Performance An enclosure system needs to minimize the heat absorption in the summer and the heat loss during winter. An efficient enclosure system needs also to be able to make smart use of sunlight and solar energy. 9.3 Enclosure Systems 9.3.2 Barrier Performance For all the facilities, keeping undesirables out is the most basic requirement. Water exclusion coupled with thermal performance is the basic for most of enclose systems. There are two areas of consideration: above the ground and below the ground. The primary performance need of a roof is water exclusion. In addition, adequate insulation, vapor migration and water barrier/removal are also important for an effective roof system. 9.3 Enclosure Systems 9.3.2 Barrier Performance Another alternative is a green roof. This roof is similar in construction to a typical ballasted roof but only the ballast is replaced with a layer vegetation. This roof alternative has advantages in reducing heating and cooling requirements, protecting roof components from UV rays, dealing with wind and temperature fluctuations, and reducing a site’s impervious surface area. 9.3 Enclosure Systems 9.3.2 Barrier Performance The ground and below-ground barrier for industrial facilities is typically a concrete slab sitting directly on the ground. The primary concern is water penetration and vapor migration. Typical, it can take 12’’ or more of concrete to prevent vapor penetration inward from the surrounding wet soil. Membranes have the potential to be 100% effective in handling vapor and water penetration, but poor design and shoddy installation can make them ineffective. 9.3 Enclosure Systems 9.3.3 Floor Performance In the most manufacturing and warehouse facilities, the floor is second only to the roof in performance requirements. Over time, concrete slab floors tend to crack, dust, and generally deteriorate. Steel fibers, synthetic fibers and post-tension reinforcements can be used to prevent cracking, while metallic or mineral hardeners can be used to improve the wear characteristics and reduce concrete dust. 9.4 Atmospheric Systems Atmospheric systems provide for the health and comfort of occupants. This gives rise to the need of building equipment and machinery for atmospheric systems. 9.4 Atmospheric Systems 9.4.1 Maintaining the Work Environment The major air quality problem in most building is the building up of odor and air-borne particles, which need to be removed by air exchange. The air exchange rate is stipulated by local code requirements as it pertains to the building use. The following table shows the typical air exchange rates for several types of building. 9.4 Atmospheric Systems 9.4.1 Maintaining the Work Environment The equipment that brings in fresh air and remove stale air is a primary consideration in planning a facility. The size of the equipment room can be decided by the following table. 9.4 Atmospheric Systems 9.4.1 Maintaining the Work Environment Duct sizes can be estimated from air quantities and air speeds in ducts. 9.4 Atmospheric Systems 9.4.1 Maintaining the Work Environment Although the air dilution method is prevalent and widely accepted, it has some drawbacks. The major drawback is that when you exhaust the air, you are removing heat. Therefore, there is a substantial loss of energy. To reduce the volume of makeup air, many operations use filters. The cleaned air is returned to the room. 9.5 Electrical and Lighting Systems The responsibility of facility planners is to specify what level of service is required and where it is required. In general, there must be sufficient capacity to satisfy the use of a facility, plus spare capacity to meet anticipated growth. 9.5 Electrical and Lighting Systems 9.5.1 Future Planning The growth in electricity need is probably the most neglected consideration in the planning and design an electrical system. The facility planners must ensure that major load requirements, both present and future, are included in the initial plan so that the electrical engineers can adequately size mains, switch gears, transformers, feeders, panel boards and circuits. The average load requirement for several building types is given in Table 9.4. 9.5 Electrical and Lighting Systems 9.5.1 Future Planning The point of service, service voltage, and metering location are then estimated with the local utility company. In addition, facility planners should determine the type and rating of all equipment to be used in the facility. The spaces required for electrical equipment and electrical closets are then determined. 9.5 Electrical and Lighting Systems 9.5.2 Lighting Lighting systems are designed using the following eight steps. Step 1: Determine the level of illumination The minimum levels of illumination for specific tasks are given in the following table (Table 9.5). 9.5 Electrical and Lighting Systems 9.5.2 Lighting After the level of illumination for a particular workstation is selected, the following factors must be considered: The nature of the tasks. The amount of reflectivity of the workstation, components, and surrounding areas. The current levels of natural or general lighting. The need for natural illumination. The worker’s age and visual acuity. 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 2: Determine the room cavity ratio (RCR) The RCR is an index of the shape of a room to be lighted. The higher and narrower a room, the larger the RCR and the more illumination needed to achieve the required level of lighting. The RCR is calculated as: (Height from the working surface to the luminary) x (Room length + Room width) (Room length) x (Room width) RCR = (5)x 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 3: Determine the ceiling cavity ratio (CCR) The greater the distance from the luminaries to the ceiling, the greater will be the CCR and the reduction in ceiling reflectance. The CCR is calculated as: (Height from luminaries to ceiling) x (RCR) (Height from the working surface to the luminaries) CCR = If luminaries are ceiling mounted or recessed into the ceiling, the reflective property of the ceiling will not be impacted by the luminaries’ mounting height, so the CCR need not be considered. 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 4: Determine the wall reflections (WR) and the effective ceiling reflectance (ECR) The WR and a base ceiling reflectance (BCR) value can be obtained from the following table (Table 9.6). 9.5 Electrical and Lighting Systems 9.5.2 Lighting If the luminaries are to be ceiling mounted or recessed into the ceiling, the ECR is equal to the BCR. If the luminaries are to be suspended, the ECR is determined from CCR, WR, and BCR using Table 9.7. 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 5: Determine the coefficient of utilization (CU) The CU is the ratio of lumens reaching the work place to those emitted by the lamp. It is function of the luminaries used, the RCR, the WR, and the ECR. The CU for the standard luminaries are given in Table 9.8 (in next slide). 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 6: Determine the light loss factor (LLF) The two most significant light loss factors are lamp lumen depreciation and luminary dirt depreciation. Lamp lumen depreciation is a gradual reduction in lumen output over the life of the lamp. Typically, lamp lumen depreciation factors are expressed as the ratio of the lumen output of the lamp at 70% of rated life to the initial value (Table 9.9). 9.5 Electrical and Lighting Systems 9.5.2 Lighting Luminary dirt depreciation is the light loss associated with the condition under which the luminary operates. The luminary dirt depreciation varies with conditions and the length of time between cleanings. A lamp luminary dirt depreciation factor is given by Table 9.10. 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 7: Calculate the number of lamps and luminaries (Required level of illumination) x (Area to be lit) (CU) x (LLF) x (Lamp output at 70% of rated life) Number of lamps = (Number of lamps) (Lamps per luminary) Number of luminaries = 9.5 Electrical and Lighting Systems 9.5.2 Lighting Step 8: Determine the location of the luminaries The number of luminaries calculated will result in the correct quantity of light. In addition to the quantity of light, the quality of light must be considered. The most important factors affecting the quality of light are glare and diffusion. To lessen glaring, overly bright luminaries should not be used, light sources should be mounted above the normal line of vision, ceilings and walls should be painted with light color to reduce contrast, background lighting should be provided if supplementary lighting is used. Diffusion of light indicates that illumination results from light coming from many directions. Fluorescent luminaries provide more diffuse light than incandescent luminaries. Also, light will not diffuse properly if luminaries are spaced too far apart. 9.5 Electrical and Lighting Systems 9.5.2 Lighting: Example 9.4 Example 9.4: A machine shop 100’x40’ with a 13’ ceiling will be illuminated for automatic machining and rough grinding. Uniform lighting is required throughout the machine shop. If the luminaries are to be ceiling mounted, all ceilings and walls are to be painted white, and all luminaries are to be cleaned every 24 months, what lighting should be specified. Solution: Step 1: Determine the level of illumination by Table 9.5 The minimum illumination level of 100 footcandles is required. 9.5 Electrical and Lighting Systems 9.5.2 Lighting: Example 9.4 Step 2: Determine the room cavity ratio Assume all working surface are 3’ from the floor. The height from the working surface to the luminary is (13 -3) = 10 foot. (5) x (10) x (100+40) (100) x (40) = = 1.75 (Height from the working surface to the luminary) x (Room length + Room width) (Room length) x (Room width) RCR = (5)x 9.5 Electrical and Lighting Systems 9.5.2 Lighting: Example 9.4 Step 3: Determine the ceiling cavity ratio The CCR need not be considered because the luminaries are ceiling mounted. Step 4: Determine the wall reflection and the effective ceiling reflectance According to Table 9.6, the wall reflectance and the base ceiling reflectance are 80%. The effective ceiling reflectance is also 80% because the luminaries are ceiling mounted. 9.5 Electrical and Lighting Systems 9