LEDs in Existing Recessed Cans – Advice to Homeowners
Recessed cans provide a big opportunity for homeowner energy saving with LEDs. Many US
homes have existing recessed can fixtures in the ceilings of kitchens, dining rooms and living areas.
These rooms typically use the recessed cans for contemporary, unobtrusive area lighting, and there may
be many recessed cans in the ceiling of each room. These fixtures were initially installed to use
incandescent or halogen reflector light bulbs with R30, PAR30 or PAR38 designations. The nature of the
rooms means that the lights are on for several hours each day. Suppose that a house has 10 such
recessed cans, that each is on for 8 hours a day, and that each now contains an energy saving “75W
equivalent” halogen light bulb which actually consumes 53W. At $0.15 a kilowatt-hour, this means that
the annual electric bill for the 10 recessed cans is $232. Changing the light bulbs in this example to a
11W directional LED light bulbs, such as PAR30LNs, will reduce the annual energy cost to $46.
While the analysis below applies to replacing a 53W halogen with a 11W LED, the concepts easily extend
to similar situations.
The economics of a change from halogen to LED must also consider the costs of the light
bulbs. The following chart shows how the payback depends on the cost of the light bulbs and the
amount of time the light bulbs are on each day.
The “payback” is the amount of time it takes for the initial cost of the LED light bulb to be compensated
by savings in electricity and in not having to replace halogen light bulbs. It is assumed that the halogen
light bulbs cost $8 each and have an average life of 1100 hours. The longer the light bulbs are on each
day, and the less expensive the LED light bulbs are initially, the quicker they pay for themselves.
Consider the following specific example based upon the ratings of actual products in the catalog of
a major home center retailer in March, 2015. In each case the product chosen is a premium lighting
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brand and a “75 W equivalent” product. The number of light bulbs is assumed to be 10, which is
representative of a modern up-scale kitchen or family room. While the payback time does not depend
on the number of bulbs, the total economic saving does.
Initial cost of 10 light bulbs
Wattage (1 light bulb)
Light output (1 light bulb, lumens)
Rated life (hours)
Dimmable
Warranty
Energy cost per year assuming 10
bulbs and $0.15/kW-hour
On 8 hours per day
On 3 hours per day
Financial payback time
On 8 hours per day
On 3 hours per day
Halogen PAR30LN
$80
53
920
1,100
yes
no
LED PAR30LN
$210
11
750
25,000
yes
3 year
$232
$87
$46
$17
0.3 years
0.9 years
At 3 hours per day, the halogen light bulbs need to be replaced after about the first year of operation,
when they reach their rated 1,100 hours. Very soon after that the total costs of the halogen light bulbs
(replacement + energy) begin to exceed those of the LED light bulbs.
This is shown graphically in the following figure, where the total costs of the two approaches are
compared as a function of time in years. The halogen costs continue to grow after the breakeven point,
with a step each year or so due to the costs of halogen replacement. The LED light bulbs do not need to
be replaced until 23 years out, when they have reached their rated 25,000 hours. By this time the
cumulative savings will have been substantial.
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This analysis, and especially the graph, assumes that all light bulbs fail or are replaced at the same time.
This is seldom the case. For the halogen light bulbs, the rated life represents the average – it is
reasonable to expect half to fail before the rated life, and half to fail after. If light bulbs are replaced as
they fail, then the replacement “steps” in the graph will disappear, and the true curve will be a
continuous smoothed version of what is shown. For the LED light bulbs, a small fraction might fail early
due to electronic component defects, but the majority of the LEDs are likely to live longer than the rated
life, becoming dimmer as they age. Irrespective of these details, the fundamental analysis stands. The
LED light bulbs are expected to pay for themselves quickly in energy costs in spite of their higher initial
cost.
An added LED benefit is less frequent light bulb replacement. In many cases, this is the intangible
benefit of not needing to get out the step ladder, unscrew the old light bulb, find a replacement light
bulb, screw in the replacement light bulb, put away the step ladder, dispose of the old light bulb, etc.
The simple act of finding a replacement light bulb can be a challenge – a trip to the hardware store,
finding the correct light bulb type, wattage, beam angle, etc. If there are 10 halogen light bulbs involved,
they are on 3 hours a day, and individual light bulbs are replaced when they fail, then on average one
light bulb will need to be replaced every month or two.
If the light bulbs are in a high, vaulted ceiling, and require a very tall ladder or scaffolding for
replacement, then the benefit of less frequent replacement is magnified. There may even be a monetary
replacement cost associated with hiring an electrician with a tall ladder or scaffolding. There is also a
safety consideration. The analysis above assumes that there is no additional replacement cost beyond
the light bulb itself. The payback for switching to LED becomes shorter if there is additional replacement
cost.
Another LED benefit is less heat. For the same amount of light, the LED approach puts about 5X less
heat into the room. This effect is readily felt simply by standing directly under a 53W halogen and then
standing under a 11W LED. In the LED case your head feels significantly cooler. The reduced heat load
with LEDs is a significant comfort advantage in warm weather, and also reduces air conditioning costs.
Always choose an ENERGY STAR™ rated product. The ENERGY STAR™ program administered by the
U.S. Environmental Protection Agency maintains rigorous specifications for LED directional products
which are suitable for use in recessed cans. Areas covered include energy efficiency plus light bulb life,
color, electrical compatibility, etc. Only products which meet those specifications are permitted to carry
the ENERGY STAR™ logo. These products are further subject to field audits to ensure that products with
the logo continue to meet the specification. The program is widely known; products without the ENERGY
STAR™ logo are likely to be inferior in performance and/or life.
Keep the purchase receipt and warranty information. One of the requirements of the ENERGY
STAR™ specification is that the LED manufacturer provide a warranty for repair or replacement for a
minimum of three years from the date of purchase. Many manufacturers now offer longer warranties.
Longer is better. This warranty is very important to the customer because of the high purchase price and
the assumption of long life in the payback analysis. At 3 hours per day, in the above example, the
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breakeven point for payback is about one years. The customer would want to hold the manufacturer
accountable if the product falls short of its warranty life.
Be concerned about the temperature in the recessed can fixtures. Be sure to purchase an LED
light bulb that is explicitly rated for use in a recessed can. A light bulb in a recessed can inherently runs
hotter than a light bulb in open air. For any product involving electronics, and most certainly for LED
products, the product life is shortened by elevated temperature. The ENERGY STAR™ specification
accounts for this by requiring a life test condition which simulates a recessed can in a ceiling with
insulation. It is likely, however, that some residential recessed can situations run hotter than this. The
exact light bulb temperature is impacted by the can design, the temperatures in the rooms below and
above the can, insulation and air flow in the space surrounding the can, etc. It is unclear how much
design margins the LED light bulbs have relative to the ENERGY STAR™ temperature condition. The best
safeguard for the consumer is to purchase an LED product with 1) the ENERGY STAR™ logo, 2) a trusted
brand, and 3) a long warranty.
Another consideration is ceiling appearance. Recessed can fixtures typically have “baffle” trim
feature, often black or white, whereby the face of a halogen PAR30 or PAR30LN light bulb is recessed
back into the ceiling by several inches. The lens face is thus not visible if viewed obliquely from a
distance. If viewed directly from below, the lens face is indeed visible, and all halogen PAR30’s look
pretty much the same irrespective of manufacturer. The same can be said if halogen PAR38’s are in the
recessed fixtures, although their faces may not be recessed as deeply. Whether halogen PAR30’s or
PAR38’s, the ceiling has a neutral, uniform appearance even if the light bulbs come from different
manufacturers.
LED PAR lamps (PAR30, PAR38, BR30, etc.) can be much more conspicuous, with each different model
and manufacturer seemingly having a different facial look. In many earlier models the LED devices were
mounted near the PAR face, so the light appears to come from a plurality of bright points which are
arranged in some pattern. The resulting ceiling appearance is thus less neutral and uniform than with
the halogen approach. The lack of uniformity would be compounded if different models from different
manufacturers were mixed together in the same ceiling. If an LED PAR light bulb were to fail in the
future, say 3 years after installation, there is no guarantee that a replacement could be found with the
same facial appearance. Thus, it would make sense to buy a spare at the time of an initial large
installation.
Newer LED PAR models come with a diffusive front face and therefore no bright points of light. These
designs provide a more neutral appearance and may be aesthetically preferable. Even with these newer
models the aesthetic appearance may differ from model to model and manufacturer to manufacturer.
Choose the color that you want. As with all LED products a range of different colors is available. On the
Lighting Facts label look for the “Light Appearance” in degrees K which is also called color temperature.
A “warm” value of 2700 K has the same appearance as the familiar old incandescent. Be sure that all of
your LED light bulbs in the ceiling have the same Light Appearance, and the value that you want.
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If you plan to operate the light bulbs on dimmers, then make sure the light bulbs are
dimmable. If the LED light bulb is rated as dimmable, the ENERGY STAR™ specification requires that the
manufacturer provide a web page providing dimmer compatibility information. If an existing dimmer is
not compatible with the LED light bulb, then it would be easy and inexpensive to replace it with one that
is.
Make sure you have enough light. Available LED PAR products typically provide slightly less light
than the halogen products they are intended to replace. In the example above, the halogen PAR30LNs
are rated at 920 lumens whereas the LED PARLNs are rated at 750. In some situations, if there was more
than enough light to begin with, this might be acceptable. In other situations, the LED light bulbs may
appear marginally too dim.
Are Integrated LED fixture products an alternative? There are products available now in which the
“light bulb” and the recessed “fixture” are integrated into a single unit. Integrated unit advantages: This
approach might provide lower cost for new construction. An integrated unit would also explicitly be
designed to manage the electronic and LED system thermals. Integrated unit disadvantages: If recessed
can fixtures are already in place, however, converting to integrated units would cost more and require
much more effort than simply putting LED PAR light bulbs into the existing cans. There is also the
question of ceiling hole size. If you are considering replacing existing cans with an integrated LED unit,
you should make sure that the ceiling hole sizes match, or be prepared to alter the hole. The integrated
fixture reduces the ability of the homeowner to troubleshoot a failed light bulb.
Someplace in between an LED light bulb in an existing recessed can and an integrated LED fixture is a
third alternative – the LED trim kit. Here an LED unit with its electronics replaces some of the trim
features on an existing can as well as the light bulb. With this approach the homeowner needs to be
sure that the LED trim kit is dimensionally compatible with the existing fixture, which is not always the
case.
With the primary approach considered here, an LED light bulb in an existing recessed can, the light bulb
and the can do not need to come from the same manufacturer. There is more opportunity to shop
around for light bulb price and performance, and it is easier to make the switch. Simply unscrew the
halogen and screw in the LED light bulb.
What about directional CFL’s as an alternative? Compact Fluorescent Light bulbs (CFL’s) are also an
energy saving alternative for existing recessed cans. Many of the things said above for LED directional
products in existing recessed cans are also true of CFL R30 and BR30 products. There are, however,
significant differences when compared to LEDs . CFL advantage: Because the CFL purchase prices are 2
to 3X lower, the payback for CFL’s is shorter than for LEDs. CFL disadvantages: Unlike LEDs, CFL’s do not
provide instant light when turned on. Further, CFL life is shortened by frequent on-off switching. Also,
LEDs have 2 to 3X shorter life than LEDs; so, over time, the lower CFL cost is offset by the shorter CFL
life. Finally, LED products generally create better directional flood and spot beams than CFL beams. CFL’s
are basically incapable of creating spot beam patterns.
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What if the light bulbs in a room are not on very much? If the incandescent or halogen light bulbs
being considered for replacement are not on very much, say less than 1 hour per day, then it is hard to
justify replacing them with expensive LED light bulbs. The less the light bulbs are on, the longer the
payback time. In such situations it might be better to leave the existing light bulbs in place and wait for
the LED replacements to become less expensive.
LED light bulbs in recessed can fixtures do make good sense today. This is especially true in
rooms with many recessed can fixtures where the light bulbs are turned on for longer than 1 hours per
day. This assumes that the existing bulbs are “75W equivalent” , and the LEDs cost less than $20 each.
The more the light bulbs are turned on, the better the economic payback to replacing inexpensive and
energy inefficient halogen light bulbs with more expensive and more energy efficient LED light bulbs.
The existence of ENERGY STAR™ ratings and multi-year warranties make this a very safe change for
homeowners. Many of the nuances of the halogen to LED conversion are discussed above.
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