Rooftop HVAC units potentially dangerous

HVAC system on roof of G Building (Photo: Leo Herbstman, The Puma Prensa)

by Leo Herbstman, editor

The heating, ventilation and air conditioning (HVAC) units replaced as part of the Maria Carrillo High School roofing project in the summer of 2018 were not inspected as required by the State of California and are potentially dangerous, according to multiple roofing and facilities experts. Contract documents and drawings created by the architect for the project, PBK, were not submitted for structural safety review to the Division of the State Architect, the agency responsible for overseeing design and construction for K-12 schools, nor was the finished work checked as required by that agency.

California Education Code requires that the DSA review and approve any construction, reconstruction, rehabilitation, alteration or addition to any school building. Maintenance, such as the roofing replacement and repair done for the MCHS project, would not require inspection. Mechanical projects such as HVAC unit installations, though, should be approved by the state agency and later inspected by an agency-certified inspector unless replacement units are of equal or lesser weight and do not increase the gravitational plus lateral forces on the building. “Gravitational force” is the downward force on the building caused by a unit’s weight, and any “lateral force” would be caused by the center of mass of a unit being off to one side.

 According to Shawn Lecrone, president of BEAM Professionals, the facilities consulting division of PBK that oversaw the MCHS project, “There was a change to the lateral loads, but in 2017 you could change the loads and the adapter curb could go to a certain height.” An adapter curb is used when a replacement HVAC unit will not fit in the original installation footprint. He said the replacement units installed are within five percent of the original units’ weight and that the loads did not violate the DSA regulations at the time according to their structural engineer.

Lecrone added, “The actual full review of the project did not go to DSA, but DSA coordinated with a structural engineer.” He said there was a meeting between a BEAM-retained structural engineer and the DSA during which they discussed plans and regulations. Though he thought there were calculations reviewed at that meeting, there is no record of those calculations to his knowledge, and he cannot remember seeing them. He added, “If I brought in the same info today, we would need to submit for structural review. If the same Carrillo project done four years ago was being done today, there would need to be a formal structural review, which would mean there would be construction documents for the structural part of the project.” 

However, according to Jennifer Lida, a public information officer for the California Department of General Services, which oversees the DSA, the use of a curb adapter likely increased the gravitational plus lateral loads, meaning a DSA review would be required.

Lida added, “Structural calculations would likely be necessary to determine possible DSA exemption from structural review,” and that any weight increase would trigger a review. In contrast to Lecrone, she said these requirements were not different in 2017. 

DSA-certified Inspector Isaac Kuster, who is currently working on a roofing and HVAC project at Santa Rosa High School, said after an examination of the MCHS contract documents and drawings, “There is no legally valid reason this project was not DSA approved. Replacing air conditioning units requires DSA approval.” In concurrence with Lida, Kuster added that if BEAM thought the HVAC replacement plan should have been exempted from DSA inspection, there should have been calculations made by a structural engineer demonstrating that the forces and weight would not be larger or heavier than those of the existing units. There is no record of a structural engineer on the MCHS project in the contract documents and drawings.

“A worst case scenario for this HVAC unit is an earthquake would pop the unit off the curb and it could fall into a classroom”

Isaac Kuster, a DSA-certified Inspector

Kuster also pointed out key differences between the SRHS plans, which are appropriately DSA approved, and the MCHS plans, which are not DSA approved. On the MCHS plans, there are no structural details showing how to attach the curb adapter to the HVAC unit, and there are no specifics about how many clips and screws would be needed to hold the unit in place. In contrast, the drawings for the SRHS project specify how many clips and screws are needed to attach the HVAC units to the curb adapter. 

Kuster said curb adapter manufacturing information and installation instructions should be called out as specifications in the contract documents. Lecrone said there were details about the curb adapter, but an examination of all publicly available documents showed no details for the adapter.

Kuster inspected a photograph of an HVAC replacement unit installed on the G Building. Kuster said that without specifications, “We can’t know if the unit at MCHS is dangerous, but I can tell you a professional educated guess is if DSA [had] checked the unit there would be more clips and screws because DSA is very cautious.” 

Closer view of curb adapter attaching HVAC unit to G Building

Kuster added that although it is unlikely for anything catastrophic to happen, with a DSA inspection, “There would be more stringent details that would make an accident even more unlikely to happen.” He continued, “A worst case scenario for this HVAC unit is an earthquake would pop the unit off the curb and it could fall into a classroom.”

A roofing consultant who has worked with SRCS before and wishes to remain anonymous so that he can continue to apply for contracts agreed with Kuster’s assessment. He said that because the units are heavier and significantly taller, a structural engineer should have worked on the project and DSA should have reviewed it. Without a structural engineer, he said, there is no way to know if a unit could withstand a wind event. He explained that because an uninspected unit may be unbalanced, there is the possibility that strong winds could push it off its mount and send it through the roof of the building.

“PBK is abandoning the standards of an architect”

Jay Takacs, CEO of mechanical engineering firm 15000 Inc.

CEO of 15000 Inc., a mechanical engineering firm, Jay Takacs, who has worked with SRCS and PBK before, said, “Without the required review, it’s not a stretch to say that the building has an unknown level of safety. There is no way I would have put my name on a project of that nature without a DSA review.”

Lecrone said BEAM did their own inspection of all of the roofs and HVAC units. Kuster, Takacs and the roofing consultant said it is abnormal that an architect would not employ a third party inspector. Takacs added, “PBK is abandoning the standards of an architect.”

PBK began providing services to SRCS in 2016 when their facilities consulting division, now known as BEAM, was called in to do an initial assessment of the roofing conditions at the schools. This assessment came because of the Measure I and L bonds that passed in 2014, which gave a total of $229 million to replace or update systems such as HVAC units and roofing. PBK followed local architect QKA, who drafted the Facilities Master Plan identifying all of the facilities needs district-wide. Even though PBK is based in Sacramento, they were recommended to then SRCS Assistant Superintendent of Business Services Steve Eichmann by Bill McGuire, then a Deputy Superintendent at Twin Rivers School District in Sacramento. McGuire later went on to provide consulting services to PBK after he left Twin Rivers.

According to SRCS Director of Facilities Michael Braff, who joined the district in March of 2017, the procedure for hiring a firm like PBK would usually begin with a Request for Proposal process where the district solicited bids from several architects. Then, they would narrow the field down to a smaller pool of candidates being considered for certain projects. In the case of hiring PBK, though, he said, “If the board has done an RFP, I have not seen it,” adding that he would have interviewed other firms before choosing.

In addition to the HVAC unit replacements, the MCHS project in the summer of 2018 included roofing work as well. According to the original presentation in Dec. 2017, Buildings B and J were to have their roofs replaced and the rest would be “upgraded.” A recent examination of the roof confirmed the two buildings had their roofs replaced but the others only had small repairs, with no changes to the overall surface. According to custodial staff, there have been leaks in the buildings without new roofs whenever it rains, including after the extensive October storms this year.

Braff, who came in after the MCHS roofing job was planned, said, “The people spearheading the project at the time did not do the sites holistically. You usually redo all of the roofs on a roofing project, and that is what I have done from [when I joined the district], essentially changing all the roofs.”

According to the roofing consultant demanding anonymity, MCHS roofs that have not been replaced, all but the ones on the B and J buildings, are at the end of their lives. 

At a 2019 school board meeting where trustees were updated on bond related roofing and HVAC work, Lecrone said of the MCHS project, “Some roofs had chronic leaks like the gym and theatre, so we replaced those, and the others we upgraded the penetrations, we did coat a couple of the roofs, and went out and were able to increase the life expectancy of the roofs.” He said that at what had been the district’s discretion, PBK spread the money out over several campuses, and that redoing every roof would have cost too much.

Then board president Jenni Klose responded, “What would be helpful is an explanation ahead of time. We got contracts to replace the roofs, and so it is news we haven’t replaced the whole roof.” The contract, however, shows only the two roofs to be replaced.

Klose and McGuire did not respond to multiple requests for comment. Eichmann would not comment.

In a recent interview, Lecrone said, “BEAM looked at the roofs across the entire district, and many of them were at the end of their life expectancy, but Carrillo had ones that had at least five years left.” He added the roofs would likely have to be replaced or resurfaced within 10 years.

Braff said the piecemeal approach cost the district more money, so there might not be enough to come back to MCHS and complete the job. 

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