Plan of Action
Published 8:31 am Tuesday, October 6, 2015
WINTON – The humidity issue that’s created mold in the heating, ventilation, and air-conditioning (HVAC) system installed on the second floor of the new Hertford County Courthouse and forced its shutdown now has a plan of resolution.
The courthouse’s designer, Paul Bonsall of Ware Bonsall Architecture in Charlotte appeared along with project mechanical engineer Jim Benson of CBHF Engineering of Wilmington before the Hertford County Board of Commissioners’ meeting Oct. 5 and outlined a plan to eliminate the problem.
The county has been troubleshooting the problem for the last three weeks and have been monitoring and abating the mold that has been identified.
“We’re putting forth a plan to totally remediate the situation,” said County Manager Loria Williams.
Bonsall wrote in a September letter to county officials that upon learning of the possible issues of mold on the second floor, they had launched immediate measures and made adjustments to the HVAC system.
“(The adjustments) will yield immediate improvement in reducing the humidity within the courtrooms and the Multi-Purpose Room,” Bonsall wrote in the letter.
Bonsall said it was discovered that the air conditioning systems were not performing as intended. He further stated that an outside air damper for the unit serving the Multi-Purpose Room was not fully closing when required.
As far as a specific reason to the high humidity levels in the three rooms, Bonsall wrote, “The building occupancy and daily usage is not as high as anticipated and the HVAC operation parameters and schedules were not set optimally for this condition, so they have adjusted fan operation and run schedules to perform better during periods of low usage.”
Bonsall said the next few weeks will be used to gauge the effectiveness of the recent adjustments and to make recommendations on how to further refine the system.
“We will propose other strategies to create a long-term solution that will involve implementing a more effective operational scheduling of the systems. The existing systems are capable of this type of scheduling, but require input from the county,” he said in the letter.
Bonsall said the engineers and designers have discussed eradication ideas, but admitted there are issues with the solutions.
Benson began by acknowledging the use of the building is part of what created some of the humidity issues.
“It’s largely because with these new efficient buildings when the lights shut off there’s nothing to make air conditioning run to de-humidify,” Benson said.
The engineer explained that they want to retrofit the HVAC system with some additional controls to keep the units running so they engage when the humidity level rises.
“You’re basically running the air conditioning and its generating heat at the same time,” he explained. “The way we have to de-humidify is to cool the air down because the cooler air is dryer and once you dry it out and put it back into the space your humidity levels will stay pretty consistent.”
Benson said the modifications to the unit are separate from the manufacturer’s specifications, thus creating an issue with the unit’s warranty.
“There are about nine months of warranty left on the unit,” he stated. “But we do have a five-year warranty on the compressor parts, and this is what the manufacturer is not willing to warranty: the modification; and so we’re struggling with how to handle that and figure out a way to insure that this equipment will continue working under the warranty that you had originally.”
Benson said they want to order the new equipment as soon as possible. He said the record humidity levels brought on by the especially hot summer and rains experienced over the last ten days have exacerbated the situation. He’d like to have a solution in place before cold weather sets it.
“This is the worst it could be,” Benson noted. “We’ve been struggling but we did get some temporary measures in place and got the humidity under control. Now we want to eliminate the problem so it does not come back.”
When asked about a timeline, Benson said if the equipment is ordered and delivered, the upgrades would take about one month with the three roof-installed units if there are no delays.
“We want to do it this way to be unobtrusive to the building’s operations since we would not have to get in and tear out,” he said. “The actual work then would take just a matter of days. When it happens we’d get it, get it done, and get out.”
Commissioner Curtis Freeman inquired that the solution is a permanent fix and not temporary.
“I want to make sure whatever’s done that it doesn’t reoccur again and that we are covered,” Freeman said.
Benson assured him it would.
“What we’re adding is active humidity control,” said Benson. “It’s a somewhat complicated process, but we try to do it indirectly by managing the loads and the running of the equipment. This is a system where if it gets too high this will pull it down.”
The engineer said the humidity control amounts to adding a coil inside the unit. Commissioner Ronald Gatling questioned modifying the unit’s warranty.
“Your findings are different from mine,” Gatling mused. “If it’s not doing what it needs to do, then it’s not working.”
The issue, the engineer explained, is avoiding a void of the five-year compressor warranty if coils are installed.
“I have to figure out a way to make that happen, to keep the warranty in place, and that’s what I’m working on,” Benson admitted. “Right now, I don’t have that plan in place.”
Benson said a similar problem occurred with the new $11 million Columbus County Courthouse in Whiteville.
“We found out there early and were able to do some mitigation to help it,” he remarked. “We made adjustments to the equipment to help it, but it’s not where we want it to be.”
Benson said these new buildings have periods where the use is intermittent and the HVAC units don’t run.
“I know (this solution) will work,” he emphasized. “It’s a very large unit because these courtrooms handle a big number of people and when there’s nobody in there and there’s no load they don’t run long enough to do very much. What we’ll be doing is artificially loading the system to keep the compressor running to de-humidify.
Benson said the timeline is affected by how soon the warranty issue can be resolved.
County Attorney Charles Revelle said he wanted to be certain that county courthouse maintenance staff would not have to make additional adjustments once the new controls are in place.
“This is a permanent fix,” Benson said. “Our main objective with the temporary adjustment was to be sure we got you under control despite the weather.”
County Manager Williams reiterated her concern over the warranty issue
“Either they say because of the re-tooling we will allow this warranty to stand, or we will not honor this warranty,” she stated. “Because when our compressors break we pay for and anticipate a five-year warranty. It’s a matter of who writes the check.”
Benson said he would continue to seek a solution to the warranty issue, and once settled would begin work on the unit modifications.