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Stairwell Lighting: An Area of Opportunity to Reduce Energy Costs
NATIONAL
REPORT—When looking for ways to green your hotel, one of the first
things you should focus on is energy efficiency. Pure economics show it
is cheaper to save a kilowatt hour then it is to produce it. Couple
this with reduced carbon emissions, and efficiency is one of the first
things a property should consider, even before looking at renewable
energy sources.
The first energy conservation measure that
should be evaluated in hospitality, whether it is a small 100-room
property or a large destination resort, is lighting. Common lighting
opportunities include T-12 to T-8 or super T-8 linear fluorescent
lighting retrofits in back-of-house applications, compact fluorescents
in guestrooms and downlight cans, and cold cathode lamps for ballroom
lighting. Until recently, stairwell lighting wasn’t looked at as an
energy conservation measure by energy services companies and facilities
managers alike.
Stairwells never represented a significant
opportunity because they are required to be lit 24 hours a day, 7 days
a week. Typically the solution for these types of areas would be a
simple T12 to T8 retrofit. Occupancy sensors that would completely shut
off the lights when the space was empty were not a consideration as
this would violate safety and fire codes. As a result, stairwell
lighting was bypassed when evaluating energy savings opportunities.
Significant Energy Savings
The
solution to this unique application is bi-level lighting which
maintains minimum illumination requirements when the stairwells are
empty, thereby maximizing energy savings. Bi-level lighting fixtures
have an ultrasonic sensor integrated into the fixture that dims the
lighting down to minimum standards—as low as 10 percent of normal
output—when no one is present. When the fixture detects someone in the
area, the lighting is restored to full brightness. This can result in
50 to 80 percent energy savings per fixture replaced. Most occupants
don’t even realize that the lights are motion sensor controlled, or
that the light levels have changed.
The significance of the
savings potential coupled with high energy costs in Hawaii make this an
attractive market for bi-level lighting. Six installations were
analyzed to determine savings potential. These installations consisted
of two high-rise office buildings, three hotels, and one hospital. In
most of these installations, the standby light levels were reduced to
10 percent in non-occupied mode to maximize the savings.
The
stairwells in the hotel proved to be the least occupied, averaging
between 1 to 3 percent. This varied based on the number of floors at
the hotel as well as what floor was being monitored. Lower floors of
the hotel had slightly more occupancy than the higher floors. The
hospital had the highest occupancy of about 7 percent, mainly because
many of the nurses used the stairs when traveling only one floor. The
two office buildings were in the middle, averaging 2 percent occupancy.
The
most significant savings was realized in one of the hotel applications
where existing 2 lamp 40-watt T 12 lamps and magnetic ballasts were
replaced with a 2 lamp bi-level fixture containing 2 lamp T8s. With 50
fixtures replaced, this amounted to an annual energy reduction of
around 37,000 kilowatt hours for an annual energy savings of just over
$5,000 or about $100 per fixture. This represents a 78 percent savings
from the installation of the bi-level lighting fixtures.
Guests Not Impacted
This
data proves the hospitality market is a prime candidate for this
technology. Because stairwells are seldom used by guests, this
technology doesn’t affect the guest experience, especially because the
fixtures return to full brightness when the space is occupied.
In
addition to the significant energy savings realized from the
implementation of bi-level lighting, this type of project can qualify
for a rebate from the local utility. The Energy Policy Act of 2005
allows for a tax deduction on these installations. One installation at
a hotel on Waikiki Beach that combined this technology with other
energy conservation measures was awarded the Energy Star Building Label
from the EPA. The Energy Star Label can provide up to 10 points for
Leadership in Energy and Environmental Design certification.
By
including the battery backup in these fixtures, it also ensures that
the emergency lighting will be available if there is a power outage
even if the fixtures were not on an emergency circuit. After the
October 2006 earthquakes in Hawaii, many hotels quickly discovered that
some of the stairwell lighting was not on emergency circuits as
previously believed. Hotel employees used glow sticks to help guests
through the stairwells while the elevators were not operable during the
power outage. The battery backup feature has increased the interest in
these bi-level fixtures as it is now not only providing energy savings
but also curing health and safety issues.
Given the success of
the technology and Hawaii’s high energy costs, bi-level lighting will
soon become the standard fixture for hotels and condominiums. Tax
deductions and increasing energy costs also makes this technology
appealing for all stairwell applications across the country. There are
very few energy conservation measures that offer between a 50 to 80
percent reduction in energy usage, which makes bi-level lighting an
exciting opportunity for you to reduce your carbon footprint. With ROIs
like that, how can you afford not to do it?
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