Combine Fiberglass and Mineral Fiber Ceiling Panels for Top-Notch Acoustic Control

Choosing the right ceiling panel material for a project makes a huge difference in managing the acoustical response of a room. An acoustical design strategy needs to include an adequate balance of both sound absorbency and sound attenuation.

Derived from ASTM C 423, which is the predominant standard for sound absorption in the U.S., noise reduction coefficient or NRC is a scalar representation of the amount of sound energy absorbed by a particular test sample. It is calculated as an arithmetic average to the nearest 0.05 over a limited frequency range (250 Hz, 500 Hz, 1,000 Hz and 2,000 Hz). In a simplification of the concept, an NRC of 0 indicates total reflection, while an NRC of 1.00 indicates total absorption.

Ceiling attenuation class or CAC is the measurement of the ceiling’s ability to block sound in a closed space from passing up into the plenum and transmitting back down into a neighboring closed space under the same plenum. The single number for CAC is derived from ASTM E1414. Ceilings with a CAC less than 25 are rated as lower performance, while those with a CAC greater than or equal to 35 are considered higher performance.

Fiberglass is more effective at quieting a room than is mineral fiber, as it performs well in both high and low frequencies. Mineral fiber tends to excel in high frequencies but lose absorption in lower frequencies. Yet, the low density of fiberglass ceiling panels, which makes them extremely resistant to moisture and sagging, at the same time limits their ability to contain sound. Consequently, fiberglass ceiling panels typically have a very high NRC, but a CAC that is on the low end.

Mineral fiber ceiling panels are denser and heavier than those made from fiberglass. It is that higher level of density that make them reasonably effective sound attenuators (meaning they impede the transmission of sound from room to room). With good sound attenuation and average sound absorption, mineral fiber ceiling panels tend to have a higher CAC and lower NRC than their fiberglass counterparts.

Building and design professionals can maximize acoustic control by combining a sound-absorbing ceiling panel with one that halts the transmission of sound waves; hence the composite ceiling panel.  With a composite panel, manufacturers such as CertainTeed laminate a layer of sound- absorbing material [fiberglass] to a layer of sound-attenuating material [mineral fiber]. The resulting product is sold and installed as a single ceiling panel. This greatly simplifies operations for the architect and contractor and provides the end user with the best of both worlds in acoustic control for many years to come.

Individually, fiberglass and mineral fiber ceiling panels have their own ways of controlling excess noise. However, when used together they produce top-notch acoustical results in a space. Whenever acoustics is a design requirement, allowing fiberglass and mineral fiber to work together in the form of a composite panel is an excellent choice.

Robert Marshall is Technical Services Manager, Ceilings for CertainTeed Corporation

Can Glass Clean-up The Gulf Oil Spill? InsulSorb® Can!

The BP oil spill has become a focal point for most Americans, including, of course, our children. My daughter’s fifth grade teacher, who is very focused on environmental issues, read the blog we posted about our product InsulSorb and our efforts to bring the product to the Gulf to help with the clean-up efforts.  The teacher then contacted me and asked if I would visit the class to demonstrate the benefits of InsulSorb as a solution to cleaning up the Gulf. 

I viewed this as a great opportunity to use a current crisis taking place to show the students a product that has been developed right here, in their community, that can assist in protecting the fragile marine environment and shorelines impacted by the oil.

First, we discussed insulation and its value in the home and other buildings as the most practical way to save energy.  Then I showed them how fiberglass insulation is made from sand and glass that is melted and formed into glass fibers and finally, the various types of insulation, including fiberglass batts, blown insulation, and spray foam insulation.

For my demonstration, I took some InsulSafe, our blown insulation product, and placed it in a beaker of water and it sank.  Next, I created an oil slick on the water and added the InsulSafe.  While it did absorb the oil, it also absorbed water and sank. 

“What would we need to do to make the insulation work?” I asked the class. After some prompting, they replied, “it needs to float.”

I explained that I challenged our scientists in our Blue Bell, Pennsylvania technical center to develop a way to make ‘glass’ float. Through a series of experiments, they developed a special, proprietary process that enabled the insulation to float.  This became InsulSorb.

We continued the experiment by placing InsulSorb in a beaker of water, and indeed, it floated.  I added oil to the water and placed the InsulSorb on top of the oil. In a short time, the InsulSorb had absorbed all the oil, which could then be easily removed, leaving behind clean water.

So, how would InsulSorb be used in the Gulf? The product can be formed into booms to be used to both contain and soak up the oil or it can be blown on top of the oil slicks and scooped up from boats. It is possible to reclaim the oil by squeezing it out of the fiber, but it will likely be more expedient to incinerate the used product.  This product will absorb 30 times its weight of oil.

The students – future scientists, environmentalists, politicians and consumers – asked some insightful questions.

We continue to work with the decision-makers in the Gulf Coast to have them utilize our product as one, viable, solution to the clean-up effort.

InsulSorb© Could Soak up Oil Spill in the Gulf

InsulSorbThe oil spill in the Gulf has brought out thousands of inventors with ideas and solutions that could, potentially, soak up the oil floating through the ocean, disrupting the delicate balance of sea life, and heading for our southern shoreline.  However, there are some solutions that have been tried and tested but have not been deployed to anywhere near their full potential.

True, the most important action right now is to stop the oil flow and British Petroleum (BP) Oil, as well as agencies like the Environmental Protection Agency (EPA) have been working tirelessly to accomplish that goal.

The hope is that whatever solutions they adopt to clean-up the spill will not cause additional environmental problems.

CertainTeed has worked with inventor Jeffrey Brelsford and his company S.E. Squared to develop unbonded, fiberglass blowing wool that can be used in booms and pads (and other methods such as direct application)  that are capable of absorbing oil spills on land or water. This fiberglass product is called InsulSorb©.

Because fiberglass is made from natural sand and rock, InsulSorb is environmentally neutral.  The Booms may also be fastened together for larger spills or the InsulSorb may be directly applied to the oil slick and reclaimed in order to treat very large and high-emergency spills such as the current Gulf spill.

InsulSorb’s other advantages include:

  • Absorbs 70 percent more than polypropylene, the product predominantly used in booms for oil spills today
  • 50 percent lighter than competitors products for easy handling and transport to spill sites
  • Dedicated production facilities for fiberglass
  • Can be recycled
  • Performs well in extreme temperatures

The advantage of this product as a solution for the current spill is that InsulSorb adsorbs more oil, is available in abundant supply and can be blown directly on the oil and collected by boat.  The logistical planning to blow the material onto the spill and collect it is the only possible challenge.

This product is one solution for cleaning up the oil spill that has been tested and used for more than 10 years, but if no one is coordinating the use of such products to begin the clean-up effort, the environmental balance, and the future of the fishing industry and tourism in that part of the country are doomed.

Mark Trabbold is Vice President, Research and Development for Insulation at CertainTeed Corporation