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The Lowdown on

Downlights

Bob Davis

Pacific Northwest National Laboratory February 16-18, 2015

2015 Grainger Show

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Downlights in the US

• 700 million downlights installed

< 1% are LED

• Current technology

10-40 lms/Watt; 1-10k hours life

• LED technology

50-75 lms/Watt; 20k+ hours life?

• Energy & cost saving potential

BUT . . . First cost? Color? Dimming? Light distribution? Reliability? Other unknowns?

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Downlighting: Incandescent / Halogen

• Low initial cost

• Shapes & sizes

• Easy to dim

• Good optical control

• Excellent color rendering

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Downlighting: Incandescent / Halogen

• Low lumens per watt

• Short life / Frequent replacement

• High operating costs

• Banned?

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Downlighting: Compact Fluorescent Lamps

• Higher lumens per watt

• Much longer life

• Reduced operating costs

(energy + maintenance)

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Downlighting: Compact Fluorescent Lamps

• Higher initial cost

• Color quality?

• Instant on / full output?

• Dimmable?

• User satisfaction?

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Downlighting: What about LEDs?

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LED options for downlights

1) Replacement lamps

2) Retrofit kits

3) Dedicated luminaires

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Replacement lamps: St. Anthony Hospital

Gig Harbor, Washington – opened 2009

5 floors, 80 beds

Daily operating hours: 15 (at least)

CFL downlights

• 4-pin CFLs, mainly 32 W

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Replacement lamps: St. Anthony Hospital

> 1,200 LED lamps installed to replace CFLs

• 2-pin/4-pin replacement lamp

• Fits into existing sockets & runs on existing ballast

• > 50% power reduction

• 4 times greater expected life

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Replacement lamps: St. Anthony Hospital

PROS

• Low labor costs (Installed by in-house facilities staff )

• <1% initial failure rate (any failures were replaced by mfr)

• Payback within 3 years based on energy & maintenance

CONS

• Legacy ballasts remain potential causes of failure

• Not dimmable

• Different distribution from fixture

• Long-term performance unknown

• Snap-back potential?

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Replacement lamps: IT Building, MGM Resorts

• IT Office Building in Las Vegas

• Three-story core-and-shell leased building, occupied April 2014

• All LED system in tenant spaces

• CFL downlights in core areas

• LED replacement lamps did not work due to ballast / fixture incompatibility

SO . . . Be sure to get samples and test them before ordering!

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Retrofit kits: Princeton’s Carl Icahn Laboratory

• Opened in Jan 2003

• 35,000 sq-ft of labs

• CFL downlights, originally lamped with 2 - 42W CFLs

• Converted to LED retrofit kits (rated for 16-18 W)

• About 80% energy savings

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Retrofit kits: Princeton’s Carl Icahn Laboratory

PROS

• Huge energy & maintenance savings

• No snap-back risk

• Possible to dim / control

• No ceiling impacts

CONS

• Higher product & install costs

• Still have old housing

• Long-term performance unknown

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Dedicated LED Luminaires: Hilton Columbus Downtown

• 450,000 square feet

• LEED Gold

• Greater Columbus Convention Center

• 484 guest rooms

• 48 suites

• Occupancy in Oct 2012

> 3700 LED Downlights!!

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Dedicated LED Luminaires: Hilton Columbus Downtown

“Though dimming is a persistent problem with

CFLs, Gonzalez notes that major hospitality

chains have standardized using switches instead

of dimmers in their rooms. Dimmability has

been an acceptable sacrifice for energy savings.”

“Meet the replacements”

Architectural Lighting, March/April 2013

- citing Domingo Gonzalez of Domingo Gonzalez Associates

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Dedicated LED Luminaires: Hilton Columbus Downtown

• Energy efficient / LEED goals

• Long life & low maintenance

– Life not affected by switching / controls

• Dimmable w/ familiar functionality

• Full output without warm-up

• Single light source appearance

• Excellent color consistency

– Downlights visible from atrium

Type GA1

15 Watt LED

Millwork uplight

Mirror lighting

Bed light

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Dedicated LED Luminaires: Hilton Columbus Downtown

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Energy Savings & Economics

6” Downlights

LED CFL: vertical CFL: horizontal

Lamp output (lms) N/A 2,400 2,400

Luminaire output

(lms) 928 1,173 981

Input power (W) 15 29 31

Luminaire efficacy

(lm/W) 62 40 32

Annual electricity

use (kWh) 203,330 377,986 406,661

Average illuminance

in entry (lx) 190 191 175

Illuminance on face

at mirror (lx) 68 101 82

Cost: 10% less to 20% more

than dimmable CFL at “book”

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Dedicated fixtures: Alston & Bird, LLP

Law Offices, Atlanta, GA

• 365,000 sq-ft, 16 floors

• LEED-CI Gold status

• Remodeled using over 2,000 recessed LED downlights, wallwashers, and accent lights

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Dedicated fixtures: Alston & Bird, LLP

Aperture

(dia.)

CCT

(K)

Luminaire Light

Output (lm)

Luminaire Power

(W)

Luminaire Efficacy (lm/W)

CFL 4.5” 3,500 980 35.3 27.8

LED 4.5” 3,500 1,316 16.0 82.3

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Dedicated fixtures: Alston & Bird, LLP

Higher initial cost

• 17% higher than equivalent CFL downlight with dimming

Energy savings:

• 22-37% savings/sq-ft (tracked, season-dependent)

Performance benefits:

• Dimmable

• Appropriate for use in video conference spaces

• Implemented controls:

– Networked lighting control system throughout

– Scene-based interface for videoconferencing

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LED options for downlights

1) Replacement lamps

2) Retrofit kits

3) Dedicated luminaires

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The Lowdown on

Downlights

New Fact Sheet coming!

Bob Davis

Pacific Northwest National Laboratory February 16-18, 2015

2015 Grainger Show