Energy Savings Escalations

Team OtisCOOL TOOLS Dallas, TX

January 27, 2007

Hypothesis

• There is substantial energy savings potential in an occupancy-controlled operation mode for Adams Mark Conference Center escalators

Definitions

• “Substantial” = 30% or greater• “Occupancy controlled” = motor goes

dormant when escalator not in use• “Not in use” = no one is on escalator

Constraints & Assumptions• Sample time was 20 minutes, on Saturday

27 January, starting at 12 noon

• Commercial building electrical rate is around $0.10 per kWh

• In a commercial building setting, cooling will dominate throughout the year, leading to 33% additional energy use for cooling caused by use of the motor

• Motor is conservatively estimated as 15 HP (48” width at 20’ rise)

MethodologyEquipment: stopwatch, MEEB,

pen, notepad, calculator, team of 3

1. Observers document interval times where passengers were not on the escalator.

2. Calculation of savings by motor power and decreased cooling load

3. Estimation of retrofit and total cost savings (give this to ASHRAE and Hotel).

Data

• UP escalator was not in use for7 minutes and 42 seconds of the20 minute sample period(= 37.1%)

• DOWN escalator was not in use for 7 minutes and 48 seconds of the 20 minute sample period(= 37.4 %)

Analysis – Motor Energy

•15 HP x 0.746 = 11.19 kW (conversion)

•11.19 kW x 1 hr x 0.10 = $ 1.12 / hr

At 37% off time,savings per hour = $ 0.414 per hour

Analysis – Cooling Energy

• 15 HP x 0.746 = 11.19 kW• 11.19 kW x 3412 = 38,180 Btu/h• 38,180 Btu/h x 1.33 = 50,780 Btu/h• 50,780 Btu/h x .0002931 = 14.88 kW

(conversion)

• 14.88 kW x 1 hr x 0.10 = $1.488/h

Summary: Projected Cost Savings

12-hour use interval[$1.488/h (cooling) + $0.414 (motor)] x 12 hours = $22.824 per dayOn a year$22.824 per day x 365 = $8,330.76

Estimated retrofit cost for user-activated sensors ??? Payback . . . .!

Walter Grondzik, gzik@polaris.netDaniel Faoro, faoro@ltu.eduAlison Kwok, akwok@uoregon.edu