by trailers of varying sizes, where head curtains must be
frequently adjusted to reach lower trailers. Head curtains that
utilize weight and gravity to create a solid connection with
the trailer top are the best option in combatting this challenge.
Weighted head curtains maintain a tight, consistent seal across
the full width of the trailer, even as it bounces during loading
and unloading. This type of header automatically adjusts to a
wide range of trailer heights without requiring pull ropes or
other forms of manual adjustment.
Trailer top corners, where the side curtains and head curtain
come together, is a notoriously difficult area to seal and
requires specially designed equipment to ensure an effective
seal. Some products exist with corner pockets that help solve
On the sides of the trailer, keep the 2. 5 cumulative square
feet of opening created by exposed hinge gaps covered
completely by hooks on the shelter side curtains.
Completing The Seal
While it is critical to effectively seals gaps at the top and
along the sides of the dock opening, don’t forget the bottom.
Gaps typically exist below and around the leveler and dock
bumpers, which present another challenge for energy costs and
Installing a seal under the leveler can offer a barrier against the
elements on the facility’s exterior. Inside, lip corner seals, filler
pads and other components keep the inside of the dock protected.
Sealing under and around the leveler will help keep dirt,
debris and refuse out of leveler pit and close gaps that allow
dirt, dust and insects into the building. Sealing these gaps will
also help reduce heat transfer through the steel leveler deck
and — as on the other three sides of the dock opening — will
help prevent heated or cooled air from escaping the building
and save thousands of dollars annually.
How HVLS Fans Improve Energy Efficiency
Effectively regulating indoor environments is an obstacle
for many manufacturing facilities. Seasonal fluctuations in
weather are an obvious challenge to indoor air quality and
temperature, as are the expansive, wide-open layouts typical of
While improvements to (or the additions of) HVAC and
building management systems (BMS) can partially address
these problems, savvy facilities managers have another
weapon in their arsenal: networked systems of HVLS fans.
HVLS fans are an economical solution providing coverage
of up to 22,000 square feet of floor space with a gentle 2 to
3 mph breeze. In fact, it takes nearly two dozen floor fans
to equal the same output as a single HVLS fan. In addition,
floor fans require more energy, make more noise and create
potential trip hazards due to electrical cords.
By mixing heat-stratified layers of air, HVLS fans reduce
energy consumption, boost HVAC system efficiency, combat air
quality-related problems and promote cost efficiency throughout
the building. What’s more, the comfort and cost-efficiency
benefits of HVLS fans can be seen across all seasons.
Savings No Matter The Season
The benefits of HVLS fans are easily noticed in warm
weather, where the gentle breeze provides an evaporative
cooling sensation, reducing the effective temperature by 7 to
11 degrees Fahrenheit in facilities without air conditioning.
In air-conditioned facilities, HVLS fans can allow a
higher thermostat setting (up to 5 degrees F) with no change
in comfort. With electricity reductions estimated at four
percent for each additional set point degree, HVLS fans can
result in annual savings of 20 percent for many facilities.
In the winter months, HVAC systems often need
artificially high set-points to maintain the desired
temperature at floor level because a 20 degree F difference
exists in comparison to the ceiling. HVLS ceiling fans
mitigate this rising heat effect by gently moving the warm
air near the ceiling back down toward the floor. When the
air reaches the floor below the fan, it moves horizontally
a few feet above the floor, eventually rising to the ceiling
where it is then cycled downward again. This process, called
destratification, creates a uniform air temperature with perhaps
a single degree difference from floor to ceiling. Thus, facilities
equipped with HVLS fans reduce the burden on their heating
system and thermostat – reducing electricity consumption and
Save Energy and Increase Profits
Any facility manager considering a retrofit will likely be
asked the expected return on investment. The right system
of dock products can deliver one with a seamless connection
from the back end of the semitrailer to the inside of the
loading dock. Inside the facility, HVLS fans typically break
even on the initial investment between six months and two
years by reducing heating bills 20 to 30 percent. Get a
complete seal at the loading and keep valuable conditioned air
inside and circulating for a maximum energy value.
Walt Swietlik is the director of customer relations and sales
support at Rite-Hite.