Lighting Research Center Lighting Research Center
    Volume 11 Issue 1
May 2010    
LED Residential Under-cabinet Luminaires
color rendering index (CRI) - A rating index commonly used to represent how well a light source renders the colors of objects that it illuminates. For a CRI value of 100, the maximum value, the colors of objects can be expected to be seen as they would appear under an incandescent or daylight spectrum of the same correlated color temperature (CCT). Sources with CRI values less than 50 are generally regarded as rendering colors poorly, that is, colors may appear unnatural. lamp rated life - The number of operating hours at which half of a large group of product samples are expected to fail. The rated life is a median value of life expectancy; individual lamp life may vary considerably from the published rated life and operating conditions (e.g., temperature, hours per start) may affect actual life because rated life is based on standard test conditions. In addition, the way a product fails can vary by technology. For example, incandescent lamps abruptly stop producing any light while LEDs are considered to have failed when their light output drops below a certain fraction of the initial level. luminaire - A complete lighting unit consisting of a lamp or lamps and the parts designed to distribute the light, to position and protect the lamp(s), and to connect the lamp(s) to the power supply. (Also referred to as fixture.) correlated color temperature (CCT) - A specification for white light sources used to describe the dominant color tone along the dimension from warm (yellows and reds) to cool (blue). Lamps with a CCT rating below 3200 K are usually considered warm sources, whereas those with a CCT above 4000 K usually considered cool in appearance. Temperatures in between are considered neutral in appearance. Technically, CCT extends the practice of using temperature, in kelvins (K), for specifying the spectrum of light sources other than blackbody radiators. Incandescent lamps and daylight closely approximate the spectra of black body radiators at different temperatures and can be designated by the corresponding temperature of a blackbody radiator. The spectra of fluorescent and LED sources, however, differ substantially from black body radiators yet they can have a color appearance similar to a blackbody radiator of a particular temperature as given by CCT. power - The power used by a device to produce useful work (also called input power or active power). In lighting, it is the system input power for a lamp and ballast or driver combination. Power is typically reported in the SI units of watts. luminous flux - Luminous radiant power, measured in lumens. The overall light output of a lamp or luminaire. uniformity - The degree of variation of illuminance over a given plane. Greater uniformity means less variation of illuminance. The uniformity ratio of illuminance is a measure of that variation expressed as either the ratio of the minimum to the maximum illuminance or the ratio of the minimum to the average illuminance. lux (lx) - A measure of illuminance in lumens per square meter. One lux equals 0.093 footcandle. efficacy - The ratio of light output (in lumens) to input power (in watts), expressed as lumens per watt (LPW). illuminance - The density of luminous flux incident upon a surface. Illuminance is measured in footcandles (lumens/square foot) or lux (lumens/square meter). One footcandle equals 10.76 lux. Models are listed first by light source, then alphabetically by brand, then by model number.

Abstract

Lighting Answers: LED Residential Under-cabinet Luminaires provides information about LED under-cabinet luminaires that were available in consumer-oriented retail stores in the Albany, New York, area in the spring of 2009. The four available linear under-cabinet luminaires intended for kitchen applications were tested to determine the amount of light each provides on countertop and backsplash areas, the uniformity and color of the light, and the efficacy of the luminaires. Traditional linear under-cabinet luminaires—two fluorescent and two incandescent xenon models—were tested for comparison. This report discusses the results of the performance testing, energy and financial savings, and other considerations such as warranties.

Introduction

In the spring of 2009, National Lighting Product Information Program (NLPIP) staff visited stores in the Albany, New York, area where people would typically buy lamps (commonly referred to as light bulbs) and luminaires for their homes to determine what LED products were available. These stores included discount retailers, wholesale clubs, supermarkets, drug stores, home improvement stores, and hardware stores. The results are described in the NLPIP document Lighting Answers: Availability of LED Lighting Products for Consumers.

One type of LED product found during the store survey was under-cabinet luminaires, which are mounted to the underside of upper cabinets in order to provide counter-top illumination or are mounted under upper shelves and in display cases. These luminaires have either linear or puck forms, and some can be “linked” or electrically connected together, so multiple luminaires can be installed more easily.

At the time of the spring 2009 survey, nine puck and six linear under-cabinet luminaires were identified through this survey, as shown in Table 1. Other under-cabinet luminaires were available through channels other than the stores visited for this survey. For example, some manufacturers produce LED under-cabinet luminaires intended for the commercial marketplace to illuminate office desks; these products were not surveyed or tested.

Table 1. LED under-cabinet luminaires available in the Albany, New York area
during the period from May 23 through June 4, 2009.*
Type Brand Model Store(s) Price (US$) Manufacturer's data on package Notes
Luminous flux (lumens) Power (W) Life
Puck Ace 3224037 Ace Hardware 34.99 NS 2.5/puck NS 3 pucks
Hampton Bay 403-144 The Home Depot 39.96 NS 2/puck NS 3 pucks, dimming
Hampton Bay 830-758 The Home Depot 33.97 NS 0.68/puck NS 3 pucks
Hampton Bay 834-355 The Home Depot 49.96 NS 0.23/puck NS 10 mini-pucks
Hampton Bay 957-254 The Home Depot 14.96 NS 2.6 20 yr 1 puck
Hampton Bay 980-984 The Home Depot 29.92 NS 2.6/puck 20 yr 3 pucks
Lights of America 7200 LED BN Ace Hardware 12.99 NS 2.5 NS 1 puck
Utilitech 283277 Lowe's 49.00 NS NS 50,000 hr 3 linked pucks
Utilitech 288741 Lowe's 21.98 NS 2.25 50,000 hr 4" rectangle
Linear GE 10408 The Home Depot 54.96 NS 5 NS 12" linkable strip
GE 10409 The Home Depot 64.98 NS 6 NS 18" linkable strip
GE 10432 The Home Depot 19.97 NS 1.5 NS Add-on 12" strip for GE model 10434
GE 10434 The Home Depot 39.97 NS 1.5 NS "Accent lighting," 12" strip
Utilitech 283278 Lowe's 59.00 NS 5.5 50,000 hr 18" strip
Utilitech 283520 Lowe's 24.98 NS NS NS 18" strip
* "NS" indicates information not supplied on package.

NLPIP staff purchased and tested four of the six available LED linear under-cabinet luminaires. Based upon the text and photographs on the packages of the GE 10434 and GE 10432, these two models are intended to provide accent lighting for bookshelves, rather than illumination on countertops. Because the intended use of these two models (and therefore their design goals and performance) is markedly different than those intended for kitchens, they were not included for performance testing. In addition to the four LED models, two fluorescent and two xenon incandescent luminaires were tested for further comparison. The eight models that NLPIP researchers tested are shown in Table 2. Bar coding stickers visible in the photographs were part of the NLPIP tracking methodology and were not found on the luminaires when they were purchased.

Table 2. Under-cabinet luminaires tested by NLPIP.
Light source Brand Model Store(s) Price (US$) Length given on package
[in. (cm)]
Photograph
LED GE 10408 The Home Depot 54.96 12 (30.5) GE model 10408 - click for larger image
GE 10409 The Home Depot 64.98 18 (45.7) GE model 10409 - click for larger image
Utilitech 283278 Lowe's 59.00 18 (45.7) Utilitech model 283278 - click for larger image
Utilitech 283520 Lowe's 24.98 18 (45.7) Utilitech model 283520 - click for larger image
Fluorescent GE 10113 The Home Depot 25.78 18 (45.7) GE model 10113 - click for larger image
Utilitech 069486 Lowe's 16.98 18.25 (46.4) Utilitech model 069486 - click for larger image
Xenon (incandescent) GE 10136 The Home Depot 46.97 18 (45.7) GE model 10136 - click for larger image
Utilitech 283542 Lowe's 34.98 17.6 (44.8) Utilitech model 283542 - click for larger image

NLPIP tested the under-cabinet fixtures based on ASSIST recommends testing procedures, described in the publication Volume 2, Issue 3: Recommendations for Testing and Evaluating Under-cabinet Luminaires. The ASSIST recommends test procedure defines an application area for under-cabinet fixtures (intended to simulate a kitchen counter and back splash) consisting of a horizontal area 24 inches (61.0 cm) deep and a vertical area 18 inches (45.7 cm) high, with a width extending 12 inches (30.5 cm) beyond the length of the luminaire on each side, as shown in Figure 1.

Figure 1. Under-cabinet luminaire test apparatus.

Test apparatus drawing

The ASSIST recommends program has published two documents to help select under-cabinet lighting:

1. Volume 2, Issue 1: A Homeowner's Guide to Residential Under-cabinet Lighting: Getting Good Lighting for Your Kitchen Counters

2. Volume 2, Issue 2: How to Select Residential LED Under-cabinet Lighting

NLPIP investigators tested the luminaires shown in Table 2 to evaluate important properties identified in these two documents.


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