Indoor air quality draws new attention as employees return to San Francisco North Bay workplaces

14 considerations for providing healthful indoor air

• Create a clean-indoor-air action plan.

• Upgrade central air filters to MERV 13, or higher rating levels, if the system can handle the air resistance. Alternatively, use the highest MERV level compatible with the filter rack, and seal edges of the filter to limit bypass.

• Change filters as needed. Clogged filters decrease HVAC efficiency and reduce air flow.

• Visually check filters monthly.

• Reduce air recirculation to avoid spreading airborne pathogens indoors.

• Keep air cleaning systems running longer hours, if possible 24/7, to enhance above actions.

• Increase and maximize the use of outside air. Five to six air changes per hour recommended.

• Maintain humidity of 40%–60% and use low speed fans to increase air flow from open windows.

• Disable demand-controlled ventilation and bring in outside air for one to two hours before and after occupancy, and especially during cleaning and disinfecting operations.

• Inspect/maintain local exhaust ventilation in rest rooms, kitchen, and cooking areas, and increase exhaust ventilation in rest rooms above code minimums.

• Work with building engineering/HVAC specialists to generate air movement that goes from clean to less clean air through positioning of air supply and exhaust air diffusers/dampers.

• If there are ceiling fans, reverse the flow direction to draw air upward, or turn them off.

• If the existing HVAC system cannot be upgraded, supplement it with other measures, such as California Air Resources Board (CARB) certified portable HEPA air cleaners in rooms with poor ventilation as well as in isolated areas.

•Consider UVGI (ultraviolet germicidal radiation) air purification solutions particularly in high-risk spaces such as waiting rooms, shelters and indoor areas with high human occupancy.

Sources: American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) and the U.S. Environmental Protection Agency.

Wildfires and COVID — both of which can threaten the quality of indoor office building air – are triggering demand for better ways to filter out contaminants such as smoke which according to the Centers for Disease Control can irritate the lungs, cause inflammation, alter immune function and increase susceptibility to respiratory infections.

“Our company has seen 35% growth in demand for air quality solutions, evidenced by increasing sales of air scrubbers, HEPA (high-efficiency particulate air) filters and MERV 13-plus filtration products, ultraviolet light systems and related solutions for businesses, residences, schools and hospitals,” said Nick Hartman, HVAC division manager for Ongaro & Sons in Santa Rosa.

The heating, cooling, plumbing, electrical and mechanical systems contractor serving Marin, Sonoma and Napa counties installed updated devices in its 7,500-square-foot main location at 2995 Dutton Ave. in Santa Rosa.

“We believe this decision convinced most of our people to come back to the workplace after the lockdown,” Hartman said. “We continue to install a range of healthy air options in several Sonoma and Marin County schools, private homes and for large commercial customers.”

High-tech solutions

There are small business or home electrostatic air filtration systems that contains several multifold, 5-inch-wide air filters on racks, They can capture particles as small as 0.1 micron in size (700 times narrower than a human hair).

Hartman said this system is up to 100 times more effective than the standard 1-inch filter and captures up to 99.98% of allergens from filtered air. That performance level has been independently verified by experts at the Harvard School of Public Health.

Also available are ozone-free air scrubbers that incorporate high-intensity UV-C light and produce negatively charged ions that inactivate airborne contaminants.

“This innovation can be installed in existing heating, ventilation and air conditioning (HVAC) system ductwork to eliminate up to 99.96% of common flu and DNA or RNA viruses, mold and bacteria while also lowering indoor air quality index (AQI) values to maintain green levels of less than 50, where pollutants cause little or no risk,” Hartman added.

The AQI index runs from 0 to 500. The higher the AQI value, the greater the level of air pollution. A good AQI level is between 0 and 50. Levels during the North Bay wildfires shot up above 300 — the hazardous level — in some areas.

Mark Hagarty, with Simpson Sheet Metal Inc. in Santa Rosa, said his firm has also seen a rise in residential customer demand for HVAC air-quality improvements and has several new installation projects underway.

“Bringing fresh outside air indoors is important. This has become a high priority for a variety of health reasons, but more can be done to enhance air quality by upgrading or replacing existing systems,” Hagarty said.

He said California’s Building Standards Code Title 24 contain “robust” regulations that contribute to achieving the state’s climate and air quality goals. In addition, The California Green Building Standard promotes healthful indoor and outdoor air quality by addressing issues of adequate ventilation, air exchange and indoor air pollution.

School air quality grants

California Air Resources Board Supervisor Pat Wong said building code revisions in 2020 addressed air-quality standards for new buildings, the construction of multifamily housing and for major upgrades to existing structures.

That year a research study at the University of California Davis and Lawrence Berkeley National Laboratory found that only 15% of public-school classrooms studied met the state’s ventilation standard. That means 85% of schools were likely “woefully under-ventilated.” The study arrived at the time the COVID-19 respiratory coronavirus was being spread by close human interaction.

As a prelude to reopening schools after mandatory COVID closures, the California Legislature passed AB 841 (The California Schools Healthy Air, Plumbing and Energy (CalSHAPE) Ventilation Program). It provides up to $600 million through two grant programs for energy upgrades and to test, adjust and repair HVAC systems in schools.

Governor Newsom signed this bill into law Oct. 1, 2020. The round 2 application deadline for both ventilation and plumbing program funds is May 31.

Demand for increasing system MERV ratings

Zach Brandner, vice president for construction with Peterson Mechanical Inc. in Sonoma, said a trend toward widespread adoption of air quality improvements during the pandemic “began slowly and did not take hold as fast as I thought it would among all sectors of the economy due to cost and maintenance issues.”

However, demand has been building from others.

“We’ve seen strong interest and follow-up from schools and medical centers for highly efficient air filtration and purification systems, as well as serious inquiries from high-tech companies (such as Keysight Technologies in Santa Rosa and others) searching for better ways to provide high air quality for clean rooms, research labs, production, testing, and other operations,” Bradner said.

Peterson has installed enhanced filtration/ventilation systems for several North Bay public schools along with Santa Rosa Junior College and Sonoma State University.

Peterson Mechanical also performed similar upgrades for three Kaiser Permanente hospitals, Sutter Santa Rosa Regional Hospital, Providence Santa Rosa Memorial Hospital, Petaluma Valley Hospital, Adventist Health St. Helena and “just about every hospital in the North Bay,” according to Brandner.

Updating aging HVAC

Part of the emerging interest in new clean air solutions stems from the need to replace aging HVAC furnace and air-conditioning equipment, according to Harvey Silverman, executive director of the Greater Bay Area Association of Plumbers, Heating, Cooling and Mechanical Contractors.

“HVAC equipment has an average lifespan of 15 to 18 years, and before that time comes, consideration should be given to updating aging systems to comply with the California Building Standards Code governing minimum ventilation rates, acceptable indoor air quality and measures to minimize adverse health effects for occupants,” Silverman said.

Decisions about upgrading HVAC in commercial buildings are usually owner dependent or property management firm driven. Such systems are not normally repaired or replaced until they must be, or when air quality rules change to meet revised and mandated criteria for increasing air exchange movement and frequency that goes beyond retrofit benefits for the existing system.

Some building owners and property managers offer tenants the option of purchasing their own air quality portable units, since the cost of replacing a commercial HVAC system for an entire building can be in the mid-six-figure range — or higher — depending on the size needed to support total building requirements.

For small businesses and residences, single-room portable or modular solutions and existing HVAC system add-on technology, typically cost from $1,200 to $2,000 for each application.

Santa Rosa-based Moore Home Services performs more than 30,000 HVAC service calls a year.

In a letter to existing and potential customers, the company said this: “Some 81% of all repairs can be prevented with annual tune-ups, but if heating and air conditioning equipment was installed before 2010, the system probably has the R-22 refrigerant fluid inside the AC to produce cold air. As of 2020, R-22 has been phased-out by the Environmental Protection Agency (EPA) to help protect the ozone layer following a determination that R-22 is an ozone depleting substance.”

Gene Davis, sales, operations and installation manager for Moore, said customers may also be eligible to receive a rebate in return for the obsolete R-22 refrigerant that can also be applied toward a new HVAC system having the replacement R410A refrigerant.

“Owners of older HVAC systems can receive cash rebates (for a limited time only) for their outdated HVAC systems that can help defray the cost of replacement units,” Davis said.

14 considerations for providing healthful indoor air

• Create a clean-indoor-air action plan.

• Upgrade central air filters to MERV 13, or higher rating levels, if the system can handle the air resistance. Alternatively, use the highest MERV level compatible with the filter rack, and seal edges of the filter to limit bypass.

• Change filters as needed. Clogged filters decrease HVAC efficiency and reduce air flow.

• Visually check filters monthly.

• Reduce air recirculation to avoid spreading airborne pathogens indoors.

• Keep air cleaning systems running longer hours, if possible 24/7, to enhance above actions.

• Increase and maximize the use of outside air. Five to six air changes per hour recommended.

• Maintain humidity of 40%–60% and use low speed fans to increase air flow from open windows.

• Disable demand-controlled ventilation and bring in outside air for one to two hours before and after occupancy, and especially during cleaning and disinfecting operations.

• Inspect/maintain local exhaust ventilation in rest rooms, kitchen, and cooking areas, and increase exhaust ventilation in rest rooms above code minimums.

• Work with building engineering/HVAC specialists to generate air movement that goes from clean to less clean air through positioning of air supply and exhaust air diffusers/dampers.

• If there are ceiling fans, reverse the flow direction to draw air upward, or turn them off.

• If the existing HVAC system cannot be upgraded, supplement it with other measures, such as California Air Resources Board (CARB) certified portable HEPA air cleaners in rooms with poor ventilation as well as in isolated areas.

•Consider UVGI (ultraviolet germicidal radiation) air purification solutions particularly in high-risk spaces such as waiting rooms, shelters and indoor areas with high human occupancy.

Sources: American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) and the U.S. Environmental Protection Agency.

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