Expanding
a business is an outward sign of success, yet this accomplishment can
also spur unexpected growing pains. That was the case when New Hampton
Metal Fab added to its facility, and heating and cooling the extra space
became a challenge. To improve the working environment, New Hampton
installed a large-diameter fan from Big Ass Fans (Lexington, Kentucky).
Now, the company has realized energy savings, and the work environment
is much more comfortable for employees.
When
New Hampton Metal Fab opened its doors in 1945 as a blacksmith shop in
northeast Iowa, the company worked out of an 800-square-foot wooden
shed. After several expansions, the third-generation, family-owned
business now fills a 53,000-square-foot facility, where it produces
molds for the pipe and precast concrete industry as well as agricultural
equipment. After a recent 12,000-square-foot expansion, the company
realized its growth created hot working conditions in the summer and
cold conditions in the winter that were diminishing employee comfort
levels and hampering productivity.
The
facility itself has little to no insulation, so the average 20°F to
80°F outside temperatures are felt throughout the shop floor. Adding to
the varying-temperature issue is a 40-foot-high ceiling in the most
recent addition. In the summer, the high ceilings make air conditioning
an uneconomical option. During the winter, the temperature difference
from floor to ceiling could range from 5°F to 30°F due to
stratification. This occurs when hot air, which is less dense than cold
air, rises. The air coming from a heating system or as a byproduct from
the facility's plasma burn table and welding station is lighter than the
rest of the air in the facility, so it collects at the ceiling while
the colder air remains at ground level. "We'd send somebody up to fix
something and they would strip down to their long Johns, while the guys
on the floor were standing there in Carhartts, basically freezing,"
explains Pete Gallup, purchasing manager.
To
eliminate these temperature variations, New Hampton originally
installed individual, 30-inch floor fans at 20 different stations. "They
moved some air in the summer, but they didn't destratify at all in the
winter," Mr. Gallup says. The company also tried installing fans on the
walls to push the warm air down during winter months, but this caused a
draft at the already cold floor level. Finally, the company removed the
wall-mounted fans and replaced them with an 18-foot-diameter PowerfoilX
fan from Big Ass Fans.
As
it turned out, the large-diameter ceiling fan solved both summer and winter
temperature-control issues for New Hampton. The key to this is
variable-speed control--running at higher speeds in the summer and lower
speeds in the winter. While adjusting the fan's speed is part of the
equation, ultimately the large-diameter, low-speed fan's immense size is
what makes it so efficient at moving large volumes of air and saving
energy.
In the summer, the fan runs at 60 to 100 percent capacity to circulate a cool breeze.
New
Hampton is able to save energy by increasing the temperature several
degrees because air movement across a person's skin creates a cooling
sensation similar to that of an air conditioned building. To achieve
this rate of effectiveness, the low-speed fan uses an airfoil/winglet
design to move air up and over obstructions. Additional AirFences
installed along the airfoil can reclaim the air sliding down the airfoil
as the fan spins, redirecting the air towards the floor and increasing
the efficiency of the fan.
In
the winter, the fan is slowed to 15 to 25 percent of maximum operating
speed to destratify air. The key to destratification is the ability to
mix the entire volume of air in the space and to do so without causing a
draft. By increasing the length of the airfoils, the large-diameter fan
is able to sweep more surface area than a smaller-diameter fan. Through
proper air circulation, warm air is pulled off the ceiling and brought
down to occupant level before being pushed out to the walls and up to
the roof to be recirculated (see diagram on page 124). Thoroughly mixing
the indoor air at New Hampton has reduced the temperature difference
between the floor level and the underside of the roof deck to less than
1°F, enabling the company to keep the facility at a uniform temperature
of 68°F. "We used to have some very cold corners we just kind of moved
away from. Nobody would work there," Mr. Gallup says. Now, employees can
work pretty much everywhere, he says.
As
an added benefit, the amount of air the fan moves increases at a much
faster rate than the amount of power it takes to turn it as the size
gets larger. So, with all things being equal, the fan will become more
efficient as its size increases. "By reducing the amount of heat trapped
at the ceiling, it's similar to turning the thermostat down five to
seven degrees," says Christian Taber, senior application engineer and
LEED AP for Big Ass Fans.
The
large-diameter fan turned out to be a good balance for New Hampton. The
company says it saved 34 percent on heating costs after the fan was
installed while providing cooling during the summer. "Welding is pretty
much a down and dirty job no matter where you do it," Mr. Gallup says.
The addition of air movement does not change this fact, but it goes a
long way to improve the overall comfort of the welders.
NEW HAMPTON METAL FAB
PROBLEM High-ceiling facility addition caused extreme temperature fluctuations from season to season
SOLUTION 18-foot-diameter PowerfoilX fan from Big Ass Fans
RESULT Uniform temperatures, improved working environment
Big Ass Fans, call 877-244-3267 or visit bigassfans.com.
Due
to the 40-ft.-high ceilings in the most recent addition at New Hampton
Metal Fab, air conditioning was not an economical option. Instead, the
company installed an 18 ft. diameter PowerfoilX fan from Big Ass Fans.
The
immense size of the large-diameter fan efficiently moves the large
amounts of air through the entire facility, leading to more comfortable
and productive employees.
During
destratification, warm air is pulled off the ceiling and brought down
to occupant level before being pushed out to the walls and up to the
roof to be recirculated. Thoroughly mixing the indoor air at New Hampton
has reduced the temperature difference between the floor level and the
underside of the roof deck to less than 1°F, enabling the company to
keep the facility at a uniform temperature of 68°F.