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15 minute quiz - PowerPoint Presentation

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Uploaded On 2019-11-28

15 minute quiz - PPT Presentation

15 minute quiz Objectives Finish with lighting design Work on HW5 or project 2 Illumination Calculation E N F LLF LOF CU A E selected illuminance fc lx N number of fixtures ID: 768399

lamp reflectance building design reflectance lamp design building fixture light lof factor llf table ceiling figure par calculate number

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15 minute quiz

Objectives Finish with lighting design Work on HW5 (or project 2)

Illumination Calculation E = N × F × LLF × LOF × CU / A E = selected illuminance [fc, lx] N = number of fixtures F = installed lumens per fixture [lm] LLF = Light loss factor depreciation, position (dust deposit) LOF = lamp operating factor Ballast, voltage CU = coefficient of utilization Fraction of light that meets the work surface A = room area [ft 2 , m 2 ]

Zonal Cavity Method Purpose is to get CU “fixture efficiency” What parameters do you need?

Figure 16-1 Ref: Tao and Janis (2001)

Calculate Cavity Ratios CR = 2.5 × PAR × h PAR = perimeter to area ratio = P/A PAR = 2 × (L+ W)/(L × W) h = height of cavity CR = 5 × (L+ W)/(L × W) × h What about CR for non-rectangular rooms?

Reflectance Experience White ceiling, R c = 70 – 80 % = ρ c White walls, R w = 60 - 70 % = ρ w Medium to light colored walls, R w = 50 % = ρ w Dark wood paneling, R w = 25 % = ρ w Floor, R f = 10-30 % = ρ f Convert to effective reflectance ( ρ cc , ρ w , ρ fc ) Tables in Tao and Janis (Table 16-6) or from manufacturer

Calculation Procedure Goal is to get CU (how much light from the fixture gets to the work surface) Data collection Room geometry Surface reflectance Fixture tables Preliminary calculations CR for room, floor, and ceiling

Calculations (continued) Table 16.6 ρ cc and ρ fc (assume ρ fc = 20% if no other information given) Table 16.7 CU Correction if ρ fc ≠ 20% Fixture table (Figure 16-6, or manufacturer) CU based on ρ cc , ρ w , RCR Use CU by multiplier from step 4.

Example Classroom (30 × 30 × 9) White ceiling, Medium colored walls , Light floor Students working on desks Fluorescent fixtures at ceiling level Use standard tables

Solution PAR = 2 × (L+ W)/(L × W) = 120ft/900ft 2 CCR = 2.5 × PAR × h c = 0 RCR = 2.5 × PAR × h r = 2.17 FCR = 2.5 × PAR × h f = 0.83 Ceiling reflectance 70% (white ceiling) Wall reflectance 50% ( medium colored walls ) Floor reflectance 30% (light color - 30 % is maximum)

Solution Use Table 16-6 Effective ceiling cavity reflectance: CCR =0, Ceiling reflectance 70% , Wall reflectance 50% → (table) → 70 % (because CRC=0) ρ CC = 70% Effective floor cavity reflectance: FCR =0.83 , Floor reflectance 30%, Wall reflectance 50% → (table) → 29% ρ FC = 28% Effective wall cavity reflectance (does not change) ρ W = 50%

Illumination Calculation E = N × F × LLF × LOF × CU / A N = number of fixtures F = Installed lamp lumens per fixture LLF = Light loss factor Depreciation, Dirt LOF = lamp operating factor Ballast, voltage CU = coefficient of utilization Fraction of light that meets the work surface

Design E = N × F × LLF × LOF × CU / A or N = E × A / (F × LLF × LOF × CU) Instilled lamp lumens per fixture F=? Light loss factor LLF=? lamp operating factor LOF=?

Lamp operating factor LOF LOF= VF × BF VF – Voltage factor Table 16-4 BF - Ballast factor Table 16.5

Lamp Loss factor LLF LLF= LLD × LDD LLD – Lamp lumen deprecation (manufacturer or Figure 15-9. When you use Figure 15-9 use values for 40% of rated lamp life.) LDD – Luminarie Dirt Depreciation Figure 16.2 (from Figure 16- 6 find maintenance category and then use Figure 16.2 )

LLD Data for fluorescent lamps

LDD Ref: Tao and Janis (2001)

Rated lamp lumens per fixture F F = Number of lamps per fixture × Lumens per lamp Number of lamps per fixture – from Figure 16- 6 Lumens per lamp – from manufacturer Finally calculate N (number of luminarie)

Summary Calculate number of fixtures need for a specific space Calculate CU Calculate: F, LLF, LOF

Grades Your course grades are in the grade book not complete; I will updated the grade book till Tuesday based on quiz and second project grades If you feel that you deserve better than what your grade shows, you can take the final exam.

Course Summary Course Objectives: 1 ) Describe the role of building environmental systems in building planning and design, 2) Research and critically analyze claims about building environmental systems made by salespeople, subcontractors, and building designers, 3) Calculate building heating, ventilating, and air conditioning loads and specify HVAC equipment for residential and light commercial construction, 4) Acquire design requirements for building electrical systems and design basic systems, 5) List characteristics of different lamps, describe building lighting designs and their consequences and demonstrate knowledge of lighting design principles.

Other Courses HVAC Design Energy Simulation in Building Design Building Energy Systems Indoor Air Quality Sustainable Building Design Smart Buildings and Cities Design of Energy Efficient and Healthy Buildings Airflow Modeling in Building Design