Due in part to the new construction boom in the wake of Hurricanes Katrina and Rita, a supply shortage caused an influx of sulfur-containing drywall that was manufactured overseas. It is allegedly causing extensive damage, including corroding the copper in air conditioner coils.

Copper coils in some a/c units are corroding and the HVAC industry is on alert. The definitive cause is still being researched, but preliminary findings are pointing to sulfur-containing drywall manufactured overseas. According to the Associated Press, “Up to 65,000 homes in the Southeast and California, including 30,000 in Florida, could contain sulfur-emitting Chinese drywall.”

To date, the U.S. Consumer Product Safety Commission (CPSC) has received over 365 reports from residents in 18 states and the District of Columbia. Due in part to the new construction boom in the wake of Hurricanes Katrina and Rita, a majority of complaints have been from Florida and Louisiana. According to the CPSC, homeowners are complaining of a rotten egg smell in their homes; health concerns such as irritated and itchy eyes and skin and respiratory problems; blackened and corroded metal components in the home; and the frequent replacement of a/c components.

Working with the Environmental Protection Agency (EPA) and the Department of Health and Human Services (HHS), the CPSC has launched a full investigation. A preliminary report released by the EPA found sulfur, strontium, and iron concentrations at higher levels in the Chinese drywall samples as compared to the U.S. drywall. Sulfur was not detected in the U.S. drywall.

The EPA is conducting more tests and samplings as it works to confirm its first findings. In the meantime, builders, contractors, manufacturers, and homeowners are seeking equitable solutions to the health, comfort, and financial problems being raised.


Not many HVAC manufacturers were willing to go on record with their thoughts and observations on this volatile issue. In the interest of getting the whole story, The NEWSallowed contractors and manufacturers to speak anonymously.

Nordyne, however, chose to address the topic publicly and the company reported it has been witnessing some “mysterious” coil failures for some time.

“Many people initially thought that the coil failures were due to manufacturing, but it just didn’t add up on our end,” said Doug Jones, vice president marketing and sales, Nordyne. “We established a team of people to research the early coil failures and had samples of those coils shipped to our labs. What we are finding is that this is an industry-wide issue, and many of the samples tested had high levels of sulfur contamination.”

With this data in hand, Nordyne is confident that the coil corrosion is an environmental issue and not a manufacturing issue. According to the company, other manufacturers have identified it as formicary corrosion, “a condition where contaminants attack the copper and form pin-hole leaks.”

“Just recently we became aware of the sulfur contributor in Chinese-manufactured drywall, along with drywall manufactured using synthetic gypsum produced by environmental sulfur scrubbers from coal-fired electric generating plants,” said Jones. “Now it is all starting to make sense, and many of our customers are realizing that we are all victims of sulfur-containing drywall product.”

Nordyne reported that contractors are seeing coils that are just black - no copper color left at all. The company also said that the corrosion happens within months, and a replacement coil can develop corrosion-related leaks within months as well, usually less than a year.

“Understandably, Nordyne is struggling with what should be done related to warranty claims on coils failing under these circumstances,” said Jones. “Going forward, we will continue to honor the coil warranty. If we suspect that the failure is related to a corrosive environment, we will have the coil shipped back to the lab for testing.”

Jones said that if the lab determines that the failure is environment-related, no subsequent coils will be covered and a recommendation that customers treat replacement coils with a recognized coating would be made.

With the heightened awareness of the environmental conditions that are allegedly contributing to the coil failures, the company is taking a proactive role with contractors and distributors so they too can recognize the signs of the damage and advise homeowners accordingly.

“We are also suggesting that dealers who see this issue treat subsequent coils with an aftermarket product that protects against corrosion,” said Jones. “We had many homeowners who thought we were just trying to shirk our responsibility and pass the buck, but at the end of the day, we never abandon the customer. Nordyne offers a very long parts warranty, which is dependent on a high caliber of manufacturing quality. The national media attention has really helped homeowners see that there is something bigger going on than just a failed air conditioner.”


One other leading HVAC manufacturer has yet to identify any alleged Chinese drywall corroded coils. “To date, our company doesn’t have any real science that tells us that the Chinese drywall has actually been the culprit of any product failures,” said the company.

Another manufacturer has only had one issue relating to Chinese drywall recently come to its attention. Addressing a homeowner in Ohio, the company had originally intended to replace the corroded coil at no charge.

“Upon further inspection, it was determined that there was a problem with the structure of the home causing the coils to leak,” said the company. “Although the root of the issue was not related to our product, once the home has been repaired, we will go back in and replace the coils at no charge as originally discussed.”

The company plans to investigate and handle each case individually with the goal of finding and correcting the issue while preserving its warranties and customer relations.

“What concerns us, is that from our experience with this issue, we have noticed that a lot of contractors do not know about this issue and have not yet been properly educated on how to correct it.”


While science and industry struggle to determine the truth as to what is causing the problems in affected homes, pressrooms and lawyers’ offices continue to buzz with updates and lawsuits. Multiple class action lawsuits have already been filed in several states, and more are currently being drafted. This issue even has Time magazine asking, “Is drywall the next Chinese import scandal?”

In the midst of the uncertainty, Florida Attorney General, Bill McCollum, released a consumer advisory warning against con artists and scams.

“If the air conditioner coils are corroded black, there is a strong likelihood that defective imported drywall is present in the home,” he stated. “Most homes that contain defective imported drywall were built between 2004 and 2008. If a home was not built during that time period it is unlikely that the product is present.”

The release also noted that homeowners should seek the counsel of the structure’s builder or a qualified “air conditioner technician” to conduct a professional visual inspection if contamination is suspected.

“The presence of defective imported drywall cannot be determined by testing the air in the home,” McCollum warned. “Additionally, if the substance is found during a visual inspection, it cannot be remedied with a spray or an ozone generator. These products may make the problem worse.”

One larger contractor operating in several states, including California and Nevada, has seen quite a few of theses corroded coils and according to him, “These things are terrible. The manufacturers we work with were initially honoring the coil replacements under warranty, but as they see this is a broader problem, some are not planning on honoring them anymore,” he said. “I really don’t think we have begun to see the scope of this corrosion problem yet.”

Publication date:06/22/2009