# Option 1:

The total annual hard-wired and plug-in lighting use for the Benchmark is determined using Equations 10–13. These equations were derived from detailed calculations using Option 2 for a cross-section of residential floor plans using typical fixtures and lamps.

Equation 10: Equation 11: Equation 12: Equation 13:

Interior hard-wired lighting = 0.8*(FFA × 0.737 + 467) kWh/yr, Interior plug-in lighting = 0.2*(FFA × 0.737 + 467) kWh/yr, Garage lighting = Garage Area × 0.3 + 29 kWh/yr, Exterior lighting = FFA × 0.17 kWh/yr

Month

Multiplier

January

0.116

February

0.092

March

0.086

April

0.068

May

0.061

June

0.055

A percentage of this hard-wired lighting energy use is associated with each month (Table 16). The total kWh/yr found in Equations 10–13 are multiplied by each of these numbers to find the kilowatt-hours used for a given month.

Month

Multiplier

July

0.058

August

0.065

September

0.076

October

0.094

November

0.108

December

0.120

Table 16. Monthly Multipliers for Hard-Wired Lighting

After dividing by the number of days in a month, one may obtain the kilowatt-hours per day. In Option 1, these numbers may then be applied to a normalized hourly profile (Figure 17 for interior, outdoor, and garage lighting) for a given day of that month and for an average city in the United States (St. Louis). The specific values for each month can be found online in the BA Analysis Spreadsheet.

0.18

# Fraction of Daily Energy

0.16

0.14

Jan Feb Mar Apr

0.12

May Jun

0.10

Jul Aug

0.08

Sep Oct

0.06

0.04

Nov Dec

0.02

0.00

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Hour of Day Figure 17. Normalized hourly lighting profile for a given month using Option 1

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