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How Maintenance Jobs Can Make Your Business Profitable
Add Value to Your Business by Meeting Indoor LPD Standards

Add Value to Your Business by Meeting Indoor LPD Standards

When you meet Lighting Power Density (LPD) standards, you’re not just fulfilling another code; you’re putting your company in a position to grow. This article will show you how simply meeting LPD standards can save your customers money and actually add value to your business.

For more insight on how to properly light an office, check out Rules for Office Lighting Success.

How can meeting LPD standards add value to your business?
Many municipalities already require contractors to meet LPD standards for all indoor lighting jobs. In the near future, most municipalities will adopt this policy. The next time you’re lighting an office, tell your customers that even though meeting these standards is a requirement, it can actually save them money, too. The Energy Policy Act (EPAct) of 2005 allows a tax deduction up to $.60 per square foot for lighting that reduces energy use by 25% to greater than 40% over the ASHREA/IES 90-2001 recommended LPD. The deduction is available through December 31, 2008 (see your local electrical utility for more details). By simply following LPD standards and telling your customers about the EPAct tax deduction, you can get more jobs, earn more profits, and add value to your business.

LPD codes based on ASHRAE
Office lighting must comply with energy power consumption limits of ANSI, ASHRAE, IESNA and local codes. Many office lighting codes reference LPD requirements and standards, including California Title 24, LEED and other state and local codes. The ASHRAE standard is the most common benchmark included in LPD codes. If you haven’t dealt with this standard in the past, you will eventually. For office spaces, the ASHRAE/IES 90.1-2004 standard is 1.0 watt per square foot. The 2001 ASHRAE/IES 90.1 standard is still current for EPAct at 1.3 watts per square foot.
 
How do you measure a building’s LPD?
LPD or interior lighting power allowance is measured using two methods, the Building Area Method and Space by Space Method. The Building Area Method multiplies the gross lighted floor area in square feet by the allowed power density for the space type listed in 2001 ASHRAE/IES 90.1. Refer to Table 9.3.1.1 to determine the LPD/interior power allowance.

The Space by Space Method uses the building type’s allowed power density for the space type listed in 2001 ASHRAE/IES 90.1, Table 9.3.1.2 multiplied by the gross floor area. This area is measured to the center of partition walls for each space enclosed by partitions greater than 80% of ceiling height. Add the interior power allowances for all of the space types to calculate the interior power allowance for the building. More information about both these methods is available in links at the bottom of this article.

Calculating the LPD of your fixture
Regardless of method of calculation, you’ll need to find out the LPD of your lighting fixtures before they’re installed. When calculating a lighting fixture’s electrical power consumption and LPD, remember that total system wattage of a lighting fixture includes the fixture’s lamp wattage and any ballast losses. Use the manufacturer's spec sheet for the ballast to determine the fixture’s total system’s power consumption. Then multiply the total system watts by the number of fixtures in the building. Divide that by the number of square feet for the space where the lights are installed to calculate the LPD/interior lighting power allowance.

The most common office lighting fixtures include recessed linear fluorescent lensed troffers, deepcell parabolic and direct/indirect fixtures. Ruud’s RG, PG, ID Series linear fluorescent fixtures are ideal for office space applications where LPD standards apply. Click here for a chart of the total system wattages for Ruud RG, PG and ID Series products. Knowing this information will help you order the correct type and number of fixtures to meet LPD standards.

Use the following links to read more specific information regarding EPAct 2005.
http://www.lightingtaxdeduction.org/s10.html http://www.lightingtaxdeduction.org/standard.html
http://www.aboutlightingcontrols.org/education/papers/tax_deduction_2005.shtml

For more information about office lighting, see our Rules for Office Lighting Success article in the May issues of E-luminations.