In 1966, the state of California responded to unhealthy levels of air pollution in a half-dozen metro areas by enacting the first vehicle exhaust regulations in the U.S.

That was only the beginning.

Since then, California has led the nation on environmental regulations, consistently setting air quality standards that exceed those established by the U.S. Clean Air Act and which have been adopted by 13 other states and the District of Columbia.

In more recent years, California has enacted some of the most proactive climate policies on the planet, with strong greenhouse gas (GHG) reduction goals, a low-carbon fuel standard, a statewide cap-and-trade system and increasingly stringent energy codes. And as wildfires, heat waves, droughts and other weather extremes continue to plague the state, it is becoming a testing ground for climate change adaptation measures in building design.

“What we’re seeing in California is forcing us to dig deeper and rethink the kinds of questions we ask of clients and the kinds of options we present to them,” said Jamie Qualk, a WSP vice president.

He highlighted three trends driven by climate change that will have a large impact on design and mechanical-electrical-plumbing (MEP) professionals in California and elsewhere: use of outside air and filtration; heat waves; and electrification.

Qualk has a good perspective on these intersecting trends from WSP’s San Francisco office, where he works with commercial, institutional and government clients who are turning to their MEP and design consultants for help adapting to the physical effects of climate change and complying with policies being enacted to mitigate climate change.

New and Challenging Requests

Because the COVID-19 pandemic coincided with some of the state’s worst wildfires, Qualk and his colleagues have, over the past two years, responded to new and challenging requests from building owners: give us the ability to shut off outside air when fires drive “parts per million” air pollutants sky high, and at the same time give us heating-ventilation-air conditioning (HVAC) systems that lessen infection risks for occupants.

“These requests are competing, since introducing more outside air is a prime strategy for managing infection risks,” Qualk said. “Installing or enhancing filtration, even potentially using HEPA filtration, is another strategy, but with the increase in pressure drop over conventional filters, fan and motor sizes many times need to be increased to maintain comfortable temperatures.”

Such design changes push up a client’s capital expenditures significantly, while the additional power load increases operational costs and GHG footprints, according to Qualk.

“To meet these conflicting demands, we need to look for robust integrated solutions that combine new occupant densification strategies with outside air, filtration and other measures,” Qualk said.

Then there’s the added complication of designing HVAC systems for heat waves. “When we’re designing for higher temperatures, bringing in more outside air increases the need for equipment and energy to temper, humidify or dehumidify that air,” he said.

Rising Temps Impact HVAC Specs

For Qualk and his colleagues, the implications of rising temperatures became very urgent and real when they responded to a heat emergency at a hospital last year in California’s Central Valley.

“The building had already been occupied for a year when some extremely hot days occurred, overwhelming the cooling capacity for a rooftop equipment room and putting the system’s electronics at risk of failure,” Qualk said.

After reviewing recent local weather observations and using software to calculate total heat loads, as the engineer of record for the original project, Qualk and his team retrofitted the system with a supplemental fan coil split system unit to maintain the temperature needed to keep equipment from failing.

Importantly, the original building design was based on American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards, but climate extremes had already driven peak temperatures beyond those design parameters.

“We see this happening elsewhere in California, in the Midwest and the Southeast,” Qualk said. “HVAC designers now have to consider that peak temperature days may be higher than ASHRAE data indicate, or that those peak temperatures may last longer.”

He wonders about existing buildings designed 20, or even just 10, years ago that are now starting to experience higher temps than they were designed to withstand.

“Because designers usually specify spare capacity, many will have a slight margin of safety,” Qualk said. “But as we see extreme temperatures occurring more often, we’ll see greater stresses on existing buildings’ HVAC systems.”

Preparing for Electrification

Compounding the challenges of designing HVAC systems for California’s changing climate is an emerging policy driver to make buildings all electric to be able to take advantage of an increasing carbon free grid that is relying to wind and solar and not fossil fuel to meet the state’s power generation requirements

“Berkeley and other jurisdictions have already banned natural gas in new buildings, and we’re expecting California’s Title 24 energy code to move toward requiring electrification as it continues to evolve in its regular three-year cycles,” Qualk said.

For the MEP contractors, system commissioning specialists and operators, “there could be a steep learning curve for this transition from equipment consuming fossil fuels to all electric equipment,” Qualk predicted.

To help clients prepare for electrification, Qualk and his clients are investing time to education about what needs to be considered for design and operations.

“We walk our clients through market pressures, and what state governments and local jurisdictions may be requiring, so they have a better understanding of what to expect today and in the future,” he said. “And because we already have large building projects that are fully electrified, we talk a lot about the implications for design.”

Preparing clients for electrification and the changing climate have rapidly become core business activities for Qualk and many of his colleagues at WSP.

“One of the things I find most remarkable about these topics is that they’re not theoretical,” Qualk said. “I’ve been an advocate for sustainability, for LEED, for increased outdoor air for many years, and it has usually felt like these were future goals. But this is happening now, in real time.”

“We have to address outside air filtration and virus prevention. We have to address smoke because of the massive wildfires that may occur 100 miles or more from a building,” he said. “We have to adapt buildings to the new peak days that will be higher than the old charts. We have to be nimble and more open to new questions and new solutions.”

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