…when the manufacturer can’t supply the hush kit you need, we can.
If you are manufacturing equipment in the US and get a contract to export it into the EU, the last thing you want is to get hung up in customs. But that’s exactly what can happen if your equipment makes noise. EU noise standards are much stricter than in the US. Your noisy equipment can get held up in customs until you get a set of OEM looking hush kits made and shipped over there.
Row after row of electronic signal processing cabinets are usually cooled by vented updrafts from the air conditioning plenum under the floating floor, but not always. Hot spots in equipment cabinets get extra cooling from air flow booster fans and blowers which always makes unplanned-for noise. That’s when a custom run of OEM matching noise baffles needs to be designed, built and delivered.
It’s a big team project, with their engineers, technicians and managers on one side and our in-house staff on the other. Typically our clients will ship or sometimes hand-deliver the blueprints and functioning parts of their noise making equipment. We also partner with a local group of talented specialty fabricators so we get the high quality metal fabrication and painting we need. The goals along with the long list of constraints are lined out by our client and we go to work. We measure the noise, and determine how it is made. We design and build models improving each one until it works as desired. We ship it to the client. After back and forth exchanges we all agree and then the production version of the baffle is designed. A sample is made and shipped. After it’s approved we fabricate the production run and deliver it.
Our happy customers include many smaller manufacturers and a few big ones, such as: FAA commercial and military airport ASR-9 radar sites, FAA air route traffic control center ARTCC sites, Westinghouse radar equipment, Raytheon contracts, Harris Corp Voice Switcher Cabinets, Liebert Air Handlers and Power Conditioners, EMC Corp’s huge hard drive memory cabinets, and for Texas Instruments, we developed our smallest baffle, about 3/8ths inch square, mounted to the flying head of their last heavy duty impact printer.
ACOUSTICAL ENGINEERING AND DESIGN
Open Baffle Most baffles involve moving air and the system is already operating at maximum head loss. Additional significant back pressure is not an option. This means we need very slick surfaces so we don't produce drag on the air flow. We can't have abrupt changes in air flow speed or direction without causing additional head loss. This means we typically work with a 100% open, straight through air flow baffle design.
Source Attenuation We analyze the noise that needs to be attenuated and where it is coming from. We locate sound appropriate sound absorbing materials in the area where the sound is the most intense so as to get the most attenuation our of a small amount of material. Frequently special aerodynamic shapes are required because the intense sound usually comes from the same place where intense originating air flows come from. We typically work well inside the bulk airflow, very close to the fan or blower.
FAA AIRPORT RADAR EQUIPMENT
We developed the noise control package for the new Westinghouse airport radar sets starting in 1988 at one site at LAX and within 5 years had built and delivered these sets the top 80 domestic commercial and military airport radar sites.
Prior to this new radar set, the old ones still used vacuum tubes, which by then could only be purchased from Russia, not a good idea. The new set was transistorized. Initially it was planned to run silent and be cooled by air conditioning units on the roof. But as it came close to the first set being delivered, the rooftop cooling plan and equipment was scrapped and huge sets of fans were installed in the unit and vents were added so it could run without any air conditioning at all.
When the first test unit was installed at LAX, no one could talk to each other or on the phone when the radar set was running. We got the call and the rest is history.
NCP-10-A, The Transmitter Baffle, is a roll around unit that has one air inlet and one air outlet. It uses a two stage acoustic system. Low frequency noise is damped out by our patented bass traps, used here for maximum volumetric efficiency. Two port holes are installed, one for a flashlight, the other for the line of sight to easily inspect the air filters. The air rush noise is attenuated by the section of parallel lined ducts.
Size:
13" x 40" x 60" Weight: 215 lbs
NCP-10-B, The Receiving Inlet Baffle, is a roll around unit that has one air inlet on top and two outlets low to the floor. It is built like the NCP-10-A except that it has been reconfigured for two outlets. It is a smaller unit because less attenuation is needed and has air filter inspection parts.
