CHARLESTON, SC — Even though the mock trial was held in a ballroom of the Westin Francis Marion Hotel here, it was accurate enough to make contractors in the audience not want to get any closer to reality.

Fictional hvac contractor XYZ HVAC Services was being sued by fictional homeowner Mr. Johnson, because moldy conditions aggravated by the 3-ton heat pump XYZ installed caused asthma in little Tricia Johnson. The Johnsons were suing for $1 million. Would they get it?

The mock trial was held by the South Carolina Association of Heating and Air Conditioning Contractors during the group’s annual convention here in January, said SCAHACC education coordinator Jim Herritage. The turnout comprised about 200 contractors, suppliers, and utility representatives.

Herritage called the trial “a way of dramatizing to our member hvac contractors that the design, installation, and service of heating and air conditioning equipment has potentially profound health-related and legal implications.”

Trial participants and contractor members were given the following background information.


Mr. and Mrs. Johnson purchased their 1,500-sq-ft, single-story home in 1998. It had been built in 1979 and still had the original 3-ton package heat pump system. That summer the John-sons made improvements to attic insulation, caulking, and weather stripping, and added storm windows and tinting.

Just before Christmas, the hvac system stopped working. Mr. Johnson found a local hvac contractor, ABC Services, in the Yellow Pages and scheduled a service call. The ABC Services tech came out the next day and discovered that the heat pump’s reversing valve needed replacing, an expensive repair for a 19-year-old system. Mr. Johnson decided to buy a new unit.

He got quotes from ABC Services and another contractor, XYZ HVAC Services. ABC Services noted that portions of the return duct system were contaminated with mold, and that these should be replaced, resealed, and reinsulated when the heat pump was replaced. XYZ HVAC Services also noted problems with the return duct system, but said they were minor and could be remedied by being thoroughly sealed with duct tape.

The companies’ equipment prices were comparable; however, ABC Services recommended a 2.5-ton heat pump and wanted an extra $400 for the return trunk repairs. XYZ quoted a 3-ton system and said they’d do the duct repairs for free. XYZ got the job.

Fast forward six months. In May 1999, nine-year-old Tricia Johnson was treated for an ear infection with antibiotics. Over the next year she had three more episodes of increasingly worse upper respiratory infections. In addition, Mrs. Johnson noticed dark spots on bathroom walls, behind the sofa, and on the outside wall of the living room. A musty smell pervaded the house.

Mr. Johnson called XYZ HVAC. A technician added some refrigerant and checked under the house, where he discovered damp conditions and recommended that the Johnsons have 6-mil polyethylene cover the damp ground.

Mr. Johnson followed that advice; the musty smell got better but did not go away completely.

In June 2000, Tricia was referred to an allergy-asthma specialist. She was soon diagnosed as having asthma and a severe allergy to mold. Tricia began allergy shots. The Johnsons were instructed to take immediate steps to reduce allergens in the home.

In September, the Johnsons replaced the carpeting in Tricia’s bedroom with low-VOC vinyl flooring. Large black spots were found on the back of the old carpet and on the floor near the outside walls. XYZ HVAC Services was called again. They cleaned the heat pump’s coils, put more duct tape on the return trunk, and recommended that the Johnsons use a special return-grille filter to remove indoor pollutants. The Johnsons followed that recommendation.

In early November 2000, Tricia was admitted to the hospital suffering an acute asthma attack. Convinced there is a link between his home’s IAQ and Tricia’s illness, Mr. Johnson retained the services of a mechanical engineer to check the home.

The engineer and a tech from A-OK Heating and Cooling visited the home just before Thanksgiving. They found the return and supply ducts grossly contaminated with mold, which they photographed. They also photographed a 4-in. gash in the bottom side of the return trunk, about 6 ft from the return box.

At two other locations they found elbows that were noticeably loose, allowing air passage. The heat pump’s blower was set on “high” fan speed, reducing the system’s ability to remove moisture during cooling.

The mechanical engineer also ran a load calculation. The home actually needed 2 tons of cooling.

Mr. Johnson asked Mr. Jones, the owner of XYZ HVAC Services, to meet with him. Mr. Johnson confronted the contractor with the mechanical engineer’s report. Mr. Jones indicated that whatever problems the home had must have been there when the Johnsons bought it, and that Mr. Johnson should take up the matter with his realtor.

Meeting with the realtor two days later, Mr. Johnson reviewed the “Home Inspection” letter furnished at closing. The inspector had clearly written under comments, “damp conditions in the crawl space.” The Johnsons had closed on the home with that condition.

Left with mounting medical and repair bills, Mr. Johnson referred the matter to his attorney. Two months later, action was brought against XYZ HVAC Services. The plaintiff alleged that his home had suffered substantial damage as a result of gross negligence on the part of XYZ HVAC Services.

Additionally, XYZ was sued for bringing mental and physical harm to the entire Johnson family, especially Tricia, who now needed steroids to help control her asthma. The papers filed asked for $1 million in damages.


Both sides met in court in January 2002. The plaintiff, Mr. Johnson, was accompanied by his legal counsel, mechanical engineer, and Tricia’s allergist.

Accompanying Mr. Jones, the defendant, was his attorney and the home inspector who completed the report before the Johnsons bought the house.

Also present was Mr. Smith, owner of ABC Services, the first company Mr. and Mrs. Johnson spoke with when they considered replacing their heat pump system.

Opening statements: The attorney for the plaintiff said he was “prepared to prove that the mold damage to the Johnson’s home and Tricia’s allergy and asthma problems were directly caused by XYZ’s failure to correctly size the new heat pump, adequately seal the crawl space return duct leaks, and operate the system’s blower on the correct speed.”

The attorney for the defendant stated that he would prove that “the cause of the Johnson home’s mold problems — moisture — was already present when they moved in”; as such, his client was blameless.

Witnesses: The attorney for the plaintiff first called Mr. Smith, owner of ABC Services, who testified that his company recommended that the Johnsons replace a part of the return trunk back in 1998.

He produced a copy of his company’s proposal; it included the verbiage, “replace portions of trunk — $400.” While there was no specific mention of mold, he told the court, “If we wanted to replace it, it must have had a problem.”

Next on the stand was Mr. Jones, owner of XYZ. He was asked if his company had performed a cooling load calculation before recommending that Mr. Johnson purchase a new, 3-ton system.

Mr. Jones indicated that his company had been in business 25 years and that they had an excellent reputation in the community for accurately sizing heating and air conditioning systems.

Under cross-examination, he admitted that XYZ had not performed a load calculation; they simply replaced the Johnsons’ old unit with one of approximately equal capacity. Mr. Jones also admitted that they had inadvertently placed the unit’s blower fan on high speed, but stressed that the duct leaks had been sealed properly with high-quality duct tape.

Mr. Roberts, owner of PDQ Heating and Cooling, was next. He affirmed that it is standard practice for residential firms to replace equipment with units of equal capacity. “If the customers were happy with their last system before it needed replacing, it is acceptable to install a new system of equal capacity.” He admitted that doing a “Manual J” load calculation is the best way of doing things.

Testimony presented by the mechanical engineer indicated the following:

  • The improvements the Johnsons had made to their home after moving in dropped its cooling requirements by slightly more than 0.5 ton (7,312 Btuh). He estimated the original heat pump was oversized by approximately 4,900 Btuh.

  • The duct leak found in the return provided a clear path for mold-laden air from beneath the home to be brought into the conditioned space.

  • Running the blower on high speed had reduced the new a/c system’s moisture-removal capability, further encouraging mold growth, and increasing the amount of crawl space air being drawn into the return path.

  • XYZ’s installation of the high-efficiency filter, with its higher pressure drop, also increased return duct leakage.

  • An analysis from Spectrum Environment Labs of Atlanta, GA, confirmed that the predominant mold strains isolated in duct-scraping samples were Aspergillus and Penicillium.

    The allergist (called by the plaintiff’s attorney) said skin testing performed on Tricia revealed that she developed a sensitivity to the same family of molds as those found beneath the home. Dr. Davidson said that Tricia would need to be under the care of a physician for the foreseeable future for the management of the asthma.

    When asked by the plaintiff’s attorney if asthma was a major contributor to missed school days for children, the physician responded, “Yes.”

    The plaintiff’s attorney followed up by asking the physician if he felt Tricia’s allergy and asthma were responsible for her missing 48 school days over the past two and a half years. The doctor said that, in his opinion, “it would certainly be a major contributing factor.”

    The defense counsel called the home inspector to the witness stand; he provided the court with a copy of his inspection report (signed by the Johnsons), and reaffirmed that the crawl space soil was damp during his inspection. During cross-examination, he conceded that he notes “damp crawl space” on close to one-third of all of the inspections he performs. “It’s just part of living in Charleston,” he said.


    Mr. Johnson’s attorney argued that:

  • Had XYZ performed an accurate load calculation, they would have seen the home needed only a 2-ton system. Instead, they installed a 3-ton system that did a poor job of removing moisture in the home.

  • XYZ continued to run the evaporator on high fan speed after being called by the Johnsons twice for mold problems; this constituted gross negligence. Running the evaporator on high fan speed caused it to remove even less moisture, contributing to mold growth inside the home.

  • Running the evaporator on high speed actually increased the amount of damp crawl space air being pulled into the Johnson’s home through the return leak.

  • Properly repairing the return duct leak would have further prevented the moist, mold-laden air from migrating into the home.

  • Adding a high-efficiency filter with its greater pressure drop caused the unrepaired return to leak even more.

    “Ladies and Gentlemen of the jury,” he concluded: “When you go to your optometrist, he doesn’t automatically prescribe the same eyeglass prescription as he did two or three years ago. He measures to see how your vision needs have changed. …XYZ had a responsibility, just like your optometrist, to measure how the Johnson’s home’s cooling needs changed. And they failed!

    “They assumed nothing had changed, and they were wrong. And then they didn’t check to see that the system was running on the correct fan speed. There too, they assumed it was running right. And they were wrong again. And — they assumed there were no duct leaks and yes, they were wrong there also. And who is the recipient of all these wrong assumptions by a company that charged many thousands of dollars for their services and expertise? Little Tricia, who has missed almost 50 days of school in the past two and a half years. …and Tricia’s parents, whom I’m sure have laid awake countless nights worrying about their daughter’s health and wondering if they can afford her medical bills and their home’s repair bills.

    “Ladies and gentlemen of the jury, I ask you to find for the plaintiff and help the heating and air conditioning community really see, with their own eyes, that conscientious, professional evaluation and service is just as important in replacing an air conditioning system as it is in replacing a new pair of eyeglasses.”

    The contractor’s attorney argued that:

  • Mr. Jones had replaced the Johnson’s heat pump in a manner that complied with prevailing customary industry practice, as testified by his competitor Mr. Roberts.

  • The moist crawl space conditions had been present at the time the Johnsons purchased the home, as stated by the inspection letter. He stressed that the Johnsons had signed the bottom of the inspection form, indicating that they had read and understood its findings. He said Mr. Johnson should have refused closing until the moisture problems were corrected or taken remedial steps immediately after moving in. “Not doing so constituted contributory negligence on Mr. Johnson’s part,” he said.

    The judge then delivered instructions to the jury and dismissed them to deliberate. The jury deliberated 15 minutes and announced their decision.

    Sidebar: Mock Trial Cast

    Asthma-allergy physician: Bruce D. Ball, MD, Allergy & Asthma Consultants, LLP, Charleston;
    Attorney for the defense: James E. Scott, Attorney at Law, Young, Clement, Rivers & Tisdale, Charleston;
    Attorney for the plaintiff: Hamilton Smith, Attorney at Law, Young, Clement, Rivers & Tisdale, Charleston;
    Home inspector: Dewey Campbell, Building Inspection Services, Charleston;
    Mechanical engineer: C.P. Thomas, P.E., Columbia, SC;
    Trial judge: Joseph R. Frasher, Attorney at Law, Executive Director, Greenville, SC;
    Homeowner, Mr. Johnson: Eddie Plowden, Berkeley Electric Cooperative, Charleston;
    Mr. Smith, owner, ABC Services: Mickey Lawler, 2nd Wind Heating & A/C Inc., Columbia;
    Mr. Jones, owner, XYZ HVAC Services: Bill Bootle, Bootle Air Systems Inc., Beaufort, SC.

    Sidebar: Guilty Or Not Guilty?

    Do you think fictional contractor XYZ HVAC Services is guilty or not guilty of negligence toward homeowner Mr. Johnson? If you were on the jury, how would you vote?

    Visit The News home page and take part in the trial by voting in our online survey. Look for the Mold Trial survey in the left-hand column. Feel free to add your comments/observations. The tally of this online vote, as well as select comments, will be published with the actual results of the mock trial in the March 25 issue of The News.