When Randy Miiller was dreaming of building a shop, he made a point of visiting other farm shops to gather ideas to incorporate into his future structure.
“Noise control was never on my shopping list, however,” the Mount Vernon, South Dakotan recalls. “And then one day I was visiting a shop, when in drives that farm's loader tractor. The lack of noise was noticeable. So I asked the farmer why his shop was so much quieter. He said his contractor installed perforated steel on part of the shop's sidewalls.”
Miiller went on to install perforated panels along the top one third of his shop's walls. The difference, he says, is surprising at times. “I recently had the combine in the shop for work and was running it,” he explains. “Now that is a noisy piece of equipment. Yet I was able to talk to others while the combine was running, thanks to those panels.”
Small holes swallow huge sounds
Those panels Miiller refers to are perforated acoustical steel. Similar in design to high-rib steel panels used to finish out shop walls, these acoustical panels feature small holes (around 3/16 inch in diameter) that comprise less than 50% of the surface of the steel. The holes may be small, but they are definitely able to cut down on noise. Part of the sound that strikes the panel passes through the holes into the fiberglass insulation behind the panel. That insulation absorbs the sounds that would otherwise bounce back into the shop and ricochet off other solid walls.
The amount of sound the panels can absorb depends on the size and number of holes in the panels. Standard panels used in rural buildings (depending on the manufacturer) can cut noise easily by 50%. “Our Hi-Rib Acoustical Steel all but eliminates excessive sound reverberation,” says Brian Haraf of Morton Buildings. “Installed in a band around or in the ceiling, the acoustical panels are designed to let sound waves pass through sound-absorbent materials in the wall and ceiling cavities, which improves the sound quality in your building.”
Their ability to deaden sound for roughly a third more than the cost of traditional panels pays off huge dividends in hearing protection. Take the combine that Randy Miiller referred to before. It can produce sound at 100 dB to 120 dB, which is bad enough in an outdoor setting. But inside a shop, those sound levels quickly escalate. Hearing damage begins at 80 dB and gets worse the longer you are exposed.
“Another huge advantage of the panels is that they make working in a shop that much more pleasant,” says Paul Hargus, who farms with his father, Dwayne, near Jackson, Minnesota.
Panels deaden tool noise, too
Hargus works as a maintenance engineer at a local manufacturing facility where he was introduced to the concept of sound-absorbing metal panels.
“When we built our shop, we had acoustical panels installed all the way around the upper part of the shop from the ceiling down around 6 feet,” Hargus explains. “You'd be amazed how much sound it absorbs. For example, we don't get that sharp ringing in our ears after operating a pneumatic impact wrench, thanks to those panels.”