Our commercial buildings are epicenters of business and entrepreneurial creation. People bring buildings to life. Magnificent buildings have the power to profoundly influence us. When we gather in the built environment, we act on ideas, we cultivate civility, leadership, empathy, and friendships—the list goes on. Within the built environment, we often feel a part of history and the future simultaneously.
On January 30, 2020, the World Health Organization (WHO) declared the COVID-19 outbreak a global health emergency. Like a tidal wave, the wreckage was severe, resulting in astounding loss of life plus social and financial damage. More than a year later, we are still swamped in rough seas. Many were sunk, some are still taking on water, others are staying afloat for now. At the time of this writing, news reports on developing virus variants are chilling.
The urgency is setting in. Before we all panic, we should remind ourselves that colleagues across diverse professions are mobilizing, planning, supporting, educating, and acting. By now, many from the commercial building community have a general understanding of air quality best practices according to industry guidelines. Webinars are plentiful. Also, under a new administration in the United States, the fog is clearing from federal and state policies. What should the industry keep in mind?
Indoor Air Quality (IAQ) –There is a myriad of healthy-building and best practices solutions on the table. It’s easier to digest the information in small bites rather than be forced to gulp it all down at once.
Although, I am the first to admit the quantity of available information can be overwhelming.
From the perspectives of the building owners and management stakeholders, what are our priorities?
- Return tenants to healthy, safe building environments?
- Retain existing leaseholders?
- Attract future occupants to innovative, healthy-optimized buildings?
At what cost? Keep in mind, as an owner or building manager, you need quantifiable options plus strategies that are customized to your specific building environment, budget and objectives. One size does not fit all.
EVALUATION AND APPLICATION ENGINEERING IS REQUIRED
Below is a high-level overview of the design-build approach to indoor air quality (IAQ) with popular equipment strategies.
Each building is unique. Air purification strategies should be applied and designed by accredited professionals familiar with industry guidelines and best practices. This may require an ecosystem of interdisciplinary collaboration amongst specialties including engineering, environmental testing, industrial hygiene (CIH) HVAC, among others. However, since there are few firms with all these resources under one roof, collaboration is key to efficiently implementing changes at the level required by a specific commercial property. Also, consider third-party testing to validate pre- and post-outcomes. Reputable contractors understand and embrace this vital progression of work.
For example: Due to active building environments and dynamic HVAC operations that are ongoing during testing, pre- and post-environmental testing may be subject to errors. To ensure accurate results, the mechanical engineer should determine HVAC control adjustment requirements prior to testing. Also prior to testing, the sampling team should check each building floor for “air purification” equipment brought in by its occupants; many of these devices produce harmful ozone and may alter outcome results.
At the time of this writing, our firm, System Inc., is involved in both equipment testing and case studies of high-rise buildings in Seattle. We are evaluating filtration and dilution, UV-C and GPS (ozone free) needlepoint bipolar ionization. This work is being performed in collaboration with Engineering Economics Inc. (EEI), a national consulting mechanical engineering group, and Intertek, a multidisciplinary environmental testing and quality assurance provider. In most states, other entities are doing similar assessments. These efforts will further inform our industry and direct future outcomes.
Equipment Strategies – Organizations such as ASHRAE, AIHA and others have issued general guidelines discussing overall best practices. In-depth information may be found at www.ashrae.org and www.aiha.org. Top priorities: Central air dilution and air filtration plus social distancing and hygiene measures.
Supplementary equipment strategies should be formulated to address building HVAC design constraints, priority areas and energy consumption. A summary of supplementary devices are listed below.
Germicidal UV-C Devices – UV-C refers to the ultraviolet wavelengths between 200 to 280 nanometers (nm). The effectiveness of UV-C devices are well-studied and accepted for both air and surface sterilization. Intensity and dwell time are primary efficacy factors. Lamps must be sized based on microbial control objectives. Common design considerations with GUV devices include:
- Potential reactivity with plastics, PVC and other exposed materials. n Safety measures required due to potential for skin and eye burns. Devices containing UV-V lamps may emit ozone. These should be avoided in occupied space. GUV radiation is only effective when in direct contact with surfaces or microbes.
- Devices using additional photocatalytic oxidation (PCO) or titanium dioxide (TiO2) elements for odor control should be avoided due to potential hazardous byproducts.
Far-UVC – Refers to the ultraviolet wavelengths between 207 to 222 nanometers (nm). Far-UVC is an emerging technology now entering the market. Microbe deactivation rates have been shown to be relatively high with greatly reduced potential for adverse exposure to skin and eyes. However, microbe deactivation rates require more time than traditional mercury vapor UV-C lamps in the 254 (nm) range.
Self-Contained Air Purification Equipment – Self-contained air purification equipment is safe, flexible, cost-effective and highly efficient. Combination air purification equipment maximizes pathogen capture and is useful where dilution (fresh air) ventilation levels are not achievable. Units include a self-contained fan, HEPA filtration and/or activated carbon with options for internal UV-C germicidal light lamps. These units are available in portable and permanent configurations. Permanent equipment types can be installed at ceiling level to handle individual rooms or common areas. Overhead placement should be considered for optimal efficacy.
CO2 and VOC Indoor Air Scrubbers – enVerid is an innovative manufacturer of air purification equipment. It has developed technology using regenerative sorbent cartridges that scrub carbon dioxide (CO2) plus a wide range of volatile organic compounds (VOCs), aldehydes, ozone, acids and PM2.5 particulate matter from building air. When used in accordance with ASHRAE standard 62.1, HLR equipment allows for significant reduction in the need for outside air (dilution) while maintaining indoor air quality. HLR technology may be retrofitted into both existing and new HVAC infrastructure.
Needlepoint Bipolar Ionization (NPBI) – Ionizers should meet UL 2998 guidelines, which validates zero ozone emissions. NPBI should not be confused with corona discharge ionization, which produces ozone hazardous to humans. In conjunction with UL 2998 approved ionization, it is recommended that prescribed dilution and filtration guidelines be employed to minimize any question of ozone, ROS or other potential byproducts. Because use of ionizers is an evolving issue with, at times, contradictory findings, employing a qualified IAQ engineer is a must.
Conclusion – In every case of supplementary equipment utilization, the objective is to do no harm. The importance of design review and validation, in accordance with industry guidelines and best practices, cannot be understated. Misapplication of any piece of equipment, regardless of type, may render the promised or potential benefits ineffective or, at worst, adversely impact human health.
A multitude of indoor air quality equipment choices and solutions exist. Professional engineering and collaboration across specialized disciplines will maximize the potential for successful outcomes. The strategies developed and employed should provide options that meet the building owner’s defined project goals and—in an objective, efficient and practical manner—be in accordance with industry standards and guidelines.
ABOUT THE AUTHOR: For more than 20 years, Ryan Brown, president of Systems Inc., has been managing complex HVAC refurbishment projects in the commercial, high-rise and manufacturing marketplaces. Established in 1963, System Inc. is a national manufacturers’ representative and a designer/ installer of air purification equipment.