For added ambient light, homeowners rely on recessed downlights or cans in their kitchens, offices, or other gathering places. With these lights in continuous use for four hours or more, opting to switch to a more energy-efficient lighting source presents ample opportunities to save money and reduce air pollution. Compared to downlights, high-efficiency halogen lamps, at less than 65 watts, not only beat CFLs, but offer superior lighting value.
For many homeowners, especially those with children, the kitchen is the
most lived-in room in the house. It's a gathering place, a workspace, a
study area, an entertainment venue and of course, a room in which to
enjoy meals together. Thus, it's not uncommon for kitchen lights to be
switched on for four or more hours per day. This presents a legitimate
opportunity to save money and reduce air pollution and landfill waste by
switching to energy-efficient lighting solutions.
As a source of both ambient and task light, recessed downlights ("cans")
are widely used in American kitchens. These fixtures push light down
and away to light an area and a work surface at the same time. To
enable the homeowner to add ambience, they're often controlled by a
dimmer switch.
For homeowners motivated to make a small investment to reduce their
electricity use and/or carbon footprint, a simple light bulb retrofit in
their existing kitchen fixtures is a smart and easy strategy. Simply
remove the existing high wattage (commonly 65-90 watts) bulbs, and
insert lower wattage eco-friendly lamps which yield equivalent light
output (lumens). But since there are two types of lower cost
energy-efficient lighting options from which to choose, which is
preferable in this application?
We've looked at this question from many angles and have concluded that
screw-in (self-ballasted) CFL reflector lamps, for many the obvious
choice, are an inferior, energy-efficient lighting solution. Very few
consumers are familiar with the new high-efficiency halogen lamps
("HEH") which have hit the market in the last few years. The best of
these models already exceed the energy efficiency requirements for
incandescent reflector lamps scheduled to take effect in July 2012.
Here, we cite nine reasons why we believe high-efficiency halogen lamps,
controlled by a pre-set dimmer switch, offer overall superior,
energy-efficient lighting value to CFLs starting with the most important
factor for electric light sources, whether energy efficient or not:
light characteristics.
Reason 1 - Great Light:
Halogen light is legendary for being white, bright, crisp,
and punchy and making colors appear vivid.
The light cast by CFL reflectors, while typically warm white,
is average at best.
Reason 2 - Superior Illuminance:
"Illuminance" describes the amount of light on a horizontal
surface, measured in "foot candles."
High-efficiency halogen lamps, especially those with a PAR
(Parabolic Aluminized Reflector) configuration, throw concentrated light
downwards measurably better than CFL reflectors.
The result? Much more artificial light where it's needed.
Reason 3 - Effortless Dimming:
No artificial light source dims better than an incandescent
lamp. High-efficiency halogen lamps use improved incandescent
technology and don't require special dimmer switches.
Dimmable CFLs cost more than non-dimmable versions. But
dimmable doesn't translate into impressive dimming performance.
Reason 4 - Dimming = Longer Lamp Life:
Dimming any lamp is an energy-efficient lighting strategy
because it reduces electricity consumption and harmful gas emissions.
There's an added green benefit when dimming high-efficiency halogen
lamps: it extends the lifetime of the lamp.
For example, constant dimming by just 15% (a pre-set dimmer
enables this) will triple the life of the bulb, thereby reducing
landfill waste and replacement costs.
For premium high-efficiency halogen lamps, this translates into
9,000 to 12,000 hours, roughly the same as the average rated life of an
Energy Star rated CFL reflector (whose projected life is static even if
dimmed).
Reason 5 - Instant On:
Just like non-halogen incandescent bulbs, halogen lamps reach
full brightness with the flick of a switch.
State-of-the-art CFL reflectors will start instantly but take
30 seconds to a minute's time to reach full brightness (depending on the
ambient room temperature).
Reason 6 - Mercury-Free:
High-efficiency halogen lamps operate without the use of
mercury.
All CFLs contain mercury which must be vaporized to create
ultraviolet energy and subsequently, visible light.
Since mercury is a toxic substance, this necessitates proper
recycling at the end of a CFL's life.
Further, while breakage in a recessed can is a low probability
risk, an accident would cause mercury to contaminate the area below.
Reason 7 - Reliability:
High-efficiency halogen lamps don't contain any electronic
components.
Unlike a screw-in CFL, which contains a precise electronic
component called a ballast, neither frequent on/off switching, nor
trapped heat will affect the performance or lifespan of these
energy-efficient lighting solutions.
Reason 8 - Lumen Maintenance:
Lumens are the measure of the amount of light emitted by a light
source. High-efficiency halogen lamps maintain their initial lumens
for as long as they operate.
CFLs, using different technology, will gradually dim by about
25% over their lifetime.
Why does this matter? Studies have shown that at age 65, the
eyes need three times more light to see as well as at age 20.
With CFLs in a kitchen, vision needs and light output are
moving in opposite directions as time passes.
The Rest of the Story - High-Efficiency Halogen Lamps Are Greener
Reason 9 - Better, REAL Energy-Efficient Lighting:
The commonly used metric for comparing energy-efficient
lighting is lumens of output per watt of electrical input. This method
is appropriate for omni-directional bulbs such as traditional A-shape
lamps and spiral CFLs.
Directional lamps (floodlights, spotlights) are different.
Their job is not to glow, but to throw light
into a defined area or onto a specific surface.
Compare the measured light (illuminance) on a horizontal
surface from two floodlights, a 16 watt CFL BR30 (630 lumens) and a 34
watt HEH PAR30 (1) (612 lumens).
The CFL has 39 lumens per watt vs. 18 for the HEH. Thus, by
conventional measures the CFL is more than twice as energy efficient.
Measured illuminance tells a very different story: the CFL
floodlight casts just 15 foot candles of light onto the work surface in
this demonstration. The HEH? 51 foot candles.(2)
Therefore, at 1.5 foot candles per watt, the HEH bulb is 60% more
efficient in real terms than the CFL (0.9 foot candles per
watt).
Or viewed another way, using typical recessed downlight
fixtures, to produce an equivalent amount of light on a kitchen
countertop or table, where important tasks such as food preparation and
schoolwork are performed, a 54 watt CFL floodlight would be needed.
Not only would such a lamp be more expensive to purchase, it
would cost 36% more to operate and generate 36% more air pollution than
the high-efficiency halogen lamp.
Notes for Previous Example
1. A 40 watt model was dimmed by 15% to reduce lumen output from 720 to
612.
2. Measured distance of each light source to the surface of the light
meter instrument was 50 inches.
Illuminating the Perks of Energy-Efficient Lighting
Impressive consumer value is sometimes found where it's least expected.
We're all for selectively installing energy-efficient lighting around
the home and place of business because it leverages the fact that the
cheapest and cleanest kilowatt of electricity is the one that's never
produced in the first place. But if light bulb buyers only paid
attention to the popular media or followed Energy Star prescriptions,
they would only know to consider CFL reflectors as an affordable,
energy-efficient lighting solution for their oft-used recessed
downlights.
As we've argued here, the exciting new high-efficiency halogen lamps
(spot and floodlights), which are generally priced on par with premium
quality dimmable CFL reflectors, are superior energy-efficient lighting
solutions for consumers who value great light characteristics, thrift,
dimming performance and environmental sustainability for their lighting
dollar.
Peter Ellinwood is the founder and owner of GreenPoma, an online retailer of
hard-to-find, best-in-breed, environmentally-friendly lighting options.
During the 25 years he spent in the insurance industry in Boston,
Baltimore, and Annapolis, he acquired an extensive background in product
management and marketing, but decided to use this knowledge for a
greater purpose - selling energy-efficient
light bulb, LED, halogen, and CFL products along with great advice.
To make a purchase or learn more about going green, please visit www.greenpoma.com.