Exceeding ASHRAE/ IESNA 90.1 Lighting Energy Study for ABC High School
Baseline Lighting Design estimated around ASHRAE/IESNA 90.1-2004/ 2007 Overall calculated building interior lighting density is 1.4 W/ft2. Exterior lighting connected load is 8.6 kw, and is controlled by combination schedule with photocell over-ride. Lighting equipment: Classrooms, offices, use T-8 lamps with electronic ballasts. The gymnasium uses MH-PS lamps with electronic ballasts. Outdoor lighting is provided by wall mounted MH luminaires for security and pole mounted MH parking and road luminaires. Controls: Classroom luminaires contain 3 lamps, and are switched in 3 levels (inner lamp, outer two lamps, all three lamps) from the classroom. Gym is controlled by zoned manual switching. Outdoor lighting is controlled by combination schedule with photocell over-ride.
Energy Efficient Lighting Design exceeding ASHRAE/IESNA 90.1-2004/ 2007 Overall calculated building interior lighting density is 1.1 W/ft2, exceeding by 22% the A/I 90.1-2004 Exterior lighting connected load is 3.9 kw, and is controlled by combination schedule with photocell over-ride. Lighting equipment: Classrooms, offices, use T-8 lamps with Hi-Ef, LBF electronic ballasts. The gymnasium uses T5HO high bay luminaires. Outdoor lighting is provided by wall mounted MH luminaires for security and pole mounted MH parking and road luminaires with reduced wattages Controls: Classrooms ceiling dual-technology occupancy sensors; luminaire mounted photosensors to control the window row. Shops and gym occupancy sensors.
Measure Name Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint. $ Cost Expectancy Simple Discounted efficient lighting (classes, corridors) 123,430 43 $5,281 $2,000 $72,000 16 9.9 13.5 $7,463 8.4% efficient lighting (Gym) 45,408 11 $2,497 $500 $4,000 8 1.3 1.4 $15,895 79.3% lighting control (classes, corridors) 69,652 - $2,566 -$300 $15,000 8 5.6 6.5 $4,895 79.3% lighting control (Gym) 7,920 - $3,002 -$50 $1,500 8 0.5 0.6 $17,655 202.7% efficient outdoor lighting 4,300 1 $237 $40 $1,000 16 3.6 4.0 $2,023 29.6% efficient parking lighting 6,880 2 $378 $70 $1,200 16 2.7 2.9 $3,689 39.8%
Indoor Lighting Baseline Studied area elem. Clas srm IES illum (lux) Bsl. illum. (lux) Luminaire type Luminaire input power (W) 500 730 2x4 3T8 fl. luminaire with acrylic lens and double switching IS-NBF el. Ballasts A/I 90.1-1999 LPD (W/ft 2 ) Baseline LPD (W/ft 2 ) Total Area (ft 2 ) Total Area % 90 1.6 1.3 20,000 17% sec. classrm 500 936 2x4 3T8 fl. luminaire with acrylic lens and double switching IS-NBF el. Ballast 90 1.6 1.6 25,320 21% shop 500 992 4 2T8 fl. strip luminaire with 10% up slotted reflector, IS-NBF el. Ballast 59 1.8 1.8 5,000 4% gym 300 607 350W MHPS lum with mixed distrib. Acrylic globe and MHPS mag. Bal. 400 1.6 1.6 14,000 12% corridor* 200 220 4 1T8 fl. cube wrapped lum., IS-NBF el. Ballast 31 0.7 1.2 8,850 7% Total 73,170 61%
Classroom 3T8- IS-NBF-90W Indoor Lighting Baseline
Gymnasium 350WPSMH-400W Indoor Lighting Baseline
Corridor 1T8- IS-NBF-31W Indoor Lighting Baseline
Outdoor Lighting Baseline Studied area IES illum (lux) Bsl. illum. (lux) Luminaire type Luminaire input power (W) A/I 90. 1-9 9 LPD (W/ft 2 ) Baseline LPD (W/ft 2 ) Total Area (ft 2 ) Total Area % perim. walkways 20 30 250W MH walpacks 300 N/A 2.3 5,000 100 Parking/ Parkade Lighting - Baseline Studied area IES illum (lux) Bsl. illum. (lux) Luminaire type Luminaire input power (W) A/I 90.1-99 LPD (W/ ft 2 ) Baseline LPD (W/ ft 2 ) Total Area (ft 2 ) Total Area % exterior parking 20 25 400W MH luminaires on 25-ft poles 450 N/A 1.8 8,000 100
Energy Efficient Design - Indoor Lighting Studied area IESNA av.illum. (lx) Design av.illum. (lx) Luminaire type and input power Luminaire input power (W) Baseline LPD (W/ft 2 ) Design LPD (W/ft 2 ) elementary classroom 500 600 4 - pendant 2T8 dir/indir, steel fl. luminaire, HiEf-IS-NBF el. Ballast (55W) in continuous row. Dimming row has same luminaires with dimming ballasts (66W) 55 66 1.3 0.9 secondary classroom 500 540 4 - pendant 2T8 dir/indir, steel fl. luminaire, HiEf-IS-NBF el. Ballast (55W) in continuous row. Dimming row has same luminaires with dimming ballasts (66W) 55 66 1.6 0.9 shop 500 735 4 2T8 fl. strip luminaire with 20% up slotted reflector, Hi-Ef IS-LBF el. Ballast 47 1.8 1.0 gym 300 520 4-T5HO high bay luminaires 230 1.6 1.2 corridor* 200 275 4 2T8 fl. cube wrapped lum. Hi-Ef IS-LBF el. Ballast 47 0.7 0.7
Energy Efficient Design - Indoor Lighting Classroom 2T8 IS-HE-LBF
Energy Efficient Design - Indoor Lighting Gymnasium 4T5HO 230W
Corridor 2T8 IS-HE-LBF Energy Efficient Design - Indoor Lighting
Energy Efficient Design - Outdoor Lighting Studied area perim. walkways IESNA av.illum. (lx) Design av.illum. (lx) Luminaire type and input power Luminaire input power (W) Baseline LPD (W/ft 2 ) Design LPD (W/ ft 2 ) 20 20 150W MH walpacks 300 2.3 2.1 Energy Efficient Design - Parking Lighting Studied area exterior parking IESNA av.illum. (lx) Design av.illum. (lx) Luminaire type and input power 20 25 400W MH luminaires on 25-ft poles (better design) Luminaire input power (W) Baseline LPD (W/ft 2 ) Design LPD (W/ft 2 ) 450 1.8 1.6
ECM #1: Efficient Indoor Lighting Design (classes, shops and corridors) Description: Upgraded fluorescent systems in classrooms, shops and corridors. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 123,430 43 $ 5,281 $ 2,000 $ 72,000 16 9.9 13.5 $ 7,463 8.4% Discussion: This was modelled with an overall LPD reduction of 26% according to the detailed lighting study.
ECM #2: Efficient Indoor Lighting Design (Gym) Description: Upgraded suspended T5HO high-bay fixtures in the gym. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 45,408 11 $ 2,497 $ 500 $ 4,000 16 1.3 1.4 $ 15,895 79% Discussion: This was modelled with an overall LPD reduction of 26% according to the detailed lighting study.
ECM #3: Automated Controls in classrooms, shops and corridors Description: Ceiling mounted occupancy sensors in classrooms; photosensors for window areas; wall mounted sensors/ switch combinations for small offices. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 69,652 - $2,566 -$300 $15,000 8 5.6 6.5 $4,895 79.3% Discussion: The overall savings for time of use reductions represent 39% of the total energy savings.
ECM #4: Automated Controls in the Gym Description: Occupancy sensors (Manual ON, Auto OFF) in the Gym. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 7,920 - $3,002 -$50 $1,500 8 0.5 0.6 $17,655 202.7% Discussion: This was modelled with an overall LPD reduction of 6% according to the detailed lighting study.
ECM #5: Efficient Outdoor Lighting Design Description: Upgraded (lower wattage) MH perimeter outdoor system with reduced wattage luminaires. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 4,300 1 $237 $40 $1,000 16 3.6 4.0 $2,023 29.6% Discussion: This was modelled with an overall LPD reduction of 10% according to the detailed lighting study.
ECM #6: Efficient Parking Lighting Design Description: Improved efficiency area lighting luminaire. Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 6,880 2 $378 $70 $1,200 16 2.7 2.9 $3,689 39.8% Discussion: This was modelled with an overall LPD reduction of 10% according to the detailed lighting study.
Conservative Design Measures (Simple Payback < 3 yrs) The following bundle incorporates all measures that have a simple payback of less than 3 years: ECM #2: Efficient Indoor Lighting Design (Gym) ECM #4: Automated Controls in the Gym ECM #6: Efficient Parking Lighting Design The economic analysis and energy savings (relative to the baseline) of the bundle, incorporating interactive effects is shown below: Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 60,208 13 5,877 520 6,700 14 1.0 1.1 $57,020 99.4%
Aggressive Design Measures (Simple Payback < 10 yrs) The following bundle incorporates all electrical measures (i.e. lighting) that have a simple payback of less than 10 years: ECM #1: Efficient Indoor Lighting Design (classes, shops and corridors) ECM #2: Efficient Indoor Lighting Design (Gym) ECM #3: Automated Controls in classrooms, shops and corridors ECM #4: Automated Controls in the Gym ECM #5: Efficient Outdoor Lighting Design ECM #6: Efficient Parking Lighting Design The energy cost of the proposed building incorporating this bundle of measures is outlined in the following table and associated graph: Annual Savings Capital Life Payback NPV IRR kwh kw $ Maint $ Cost Expectancy Simple Discounted 257,590 57 13,961 2,260 94,700 14 5.8 6.9 $ 66,877 16.9%