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Covid-19 and its Implications for Systems Design HVAC Systems and Air Quality The Covid-19 Pandemic has forced building owners and engineers to take a deeper look at HVAC systems and how spaces are treated for human occupancy in light of the new emphasis on air quality. Air quality improvements, when applied to HVAC systems, are intended to reduce viral transmission rates, decrease instances of indoor mold and bacterial growth, and reduce respiratory infections due to indoor environmental conditions. To achieve these improvements in air quality, spaces should be conditioned, ventilated, humidified, filtered, and virus eradication technologies implemented in some cases. If implemented, these measures will help get us through the current pandemic, as well as improve our health thereafter. This may sound like a major renovation to your HVAC system, but it doesn’t have to be. Let’s dig into each measure. Conditioning Heating and Cooling are basic principles for both human comfort and maintaining strong immune systems. The ANSI/ASHRAE Standard 55: Thermal Environmental Conditions for Human Occupancy addresses indoor environmental and personal factors and specifies an optimal temperature range to ensure a healthy environment for building occupants. Specifically, the range of 68° to 75° F is desired in the winter, while 75° to 80° F is preferred in the summer months. Cooling has the added benefit of dehumidifying the surrounding air; we will discuss why controlling humidity is important in the next section. Currently in the marketplace, there are retrofit options for residential and smallscale commercial projects to incorporate

combined performance of HEPA filtration, UV air purification, and odor removal in one self-contained unit. For variable refrigerant volume systems (VRV systems), it is recommended to upgrade filters to MERV-13 where possible and ensure effective air seals. For non-ducted indoor VRF units, upgrading existing filters may not be feasible. In these cases, ASHRAE recommends adding portable room cleaners with HEPA filters or filters with a higher MERV rating. Figure 1 - Filtration Installation Options Installation (3 options) Stand-Alone

Duct-Mounted (Bypass)

Added Ducts Joined to ducts with collars

• Increased transmission of some airborne viruses and droplets (COVID-19 still being studied) • Increased survival rate of pathogens • Decreased effectiveness of hand hygiene and surface cleaning due to surface recontamination or drying of disinfectants too quickly Buildings that have cooling systems are dehumidified in the summer months as a result of the cooling process, but most buildings are not provided with humidity control during winter operation. Respiratory viral infections are most common between November and April. Figure 2 Optimum Relative Humidity Range for Minimizing Adverse Health Effects Optimum Zone

Decrease in Bar Width Indicates Decrease in Effect

Bacteria Viruses Fungi

Protective grids on top and bottom

Openings in back of unit

Versatile unit that can be positioned horizontally or vertically

As shown above in Figure 1, standalone HEPA filtration, UV air purification, and odor removal units are available in three options for retrofit applications. Humidity Humidity levels between 40%-60% are the ideal range. Humidity ranges above 60% can lead to bacteria and mold growth, and increase the viral transmission rate; levels below 40% have been linked to the issues below: • Reduction of healthy immune system function (respiratory epithelium, skin, etc.)


Mites Respiratory Infections Allergic Rhinitis Chemical Interactions Ozone Production 1 Insuffient Data Above 50% Relative Humidity


10 20

30 40 50 60 70 80 Relative Humidity (%)


Providing 40% to 60% humidity may not be practical for all buildings as the envelope may not be designed to mitigate condensation. As illustrated in Figure 2, however, some humidification is better continued on page 2

IN THIS ISSUE Covid-19: Systems Design


Wireless Access Points


Women in Engineering Revit® Corner


Project Highlight


“Covid-19: Systems Design” continued from page 1

than no humidification. Where an existing building’s envelope is a concern, an appropriate relative humidity level can be developed and applied to almost any existing structure.

Figure 4 - MERV Building Filtration

Figure 3 - Wall-mounted Electric Humidifier and Assoicated Fan Pack Figure 3 - Wall-mounted electric humidifier and assoicated fan pack

• Fibrous surfaces • Biological growth on HVAC coils • Duct distribution cleaning

Image 1 - Biological Growth on HVAC Coils and Drain Pans

For retrofitting an existing building to provide humidification, there are centralized and localized options that can be explored. Humidifiers can be supplied by various energy sources, including electricity, natural gas or propane, or steam boilers. Centralized options include retrofitting air handling units to include either unit-mounted or duct-mounted distribution grids, associated humidifiers, and controls. Where existing air handling units cannot be retrofit to incorporate humidification, there are options for direct room humidification systems that include wall-mounted humidifiers with steam blowers or fan packs that disperse steam directly into open spaces. Wall-mount humidifiers are ideal when space is limited and installation in finished spaces are required. These units also allow for easy installation for plumbing and electrical connections.

Virus Eradication Technologies It is important to ensure that all of the air delivered to occupied spaces is being filtered. Unfortunately, it is not uncommon to see air completely bypass filters due to poorly gasketed filter racks or failed gaskets between the filter media and the equipment. As discussed above, where upgrading existing filters may not be feasible, ASHRAE recommends adding portable room cleaners with HEPA filters or filters with a higher MERV rating. HVAC System Cleaning To ensure that HVAC systems are not compromising air quality, systems must be cleaned regularly and the following issues scrutinized: • Pooling water

Ultraviolet Germicidal Irradiation ASHRAE strongly recommends the use of Ultraviolet Germicidal Irradiation or UVGI, which is effective against viruses, bacteria, and mold spores. Here are just some of the benefits of UVGI: • UVGI disinfects live critical air streams circulating throughout facilities. • Infectious airborne microbiological agents, too small to be captured by filtration, can be disinfected as they pass through the “blanket of UVC energy.” • Broad-spectrum UV light, with wavelengths of 200 to 400 nm, has long been recognized as effective against viruses, including the SARS CoV-2 (novel coronavirus) which causes COVID-19. UV light is continued on page 6

AIA Registered Provider Kohler Ronan is a registered provider of AIA Continuing Education Credits. Our professionals have prepared several presentations on relevant and timely industry topics. We would be pleased to visit your offices and share these presentations. To learn more, or to schedule a visit, please contact Joe Lembo at 203.778.1017 or via email at krce@kohlerronan.com.

Filtration Standard building filtration is generally MERV-8 to MERV-10. Viruses, mold, and bacteria begin to be filtered at MERV-13. Ideally, spaces should seek to achieve MERV-16 wherever possible.

NYSERDA Approved Provider Kohler Ronan is an approved Technical Consultant for the New York State Energy Research & Development Authority’s (NYSERDA) Commercial New Construction Program. Under this program, we will provide technical support in the form of energy modeling and controls commissioning to assess and determine appropriate energy efficiency opportunities for New Construction and Substantial Renovation Projects. For details, please email Madhav Munshi at mmunshi@kohlerronan.com.


Wireless Access Points: Best Practices for Successful Deployment “Can we locate Wireless Access Points above the ceiling so they are out of sight?” This is a common question architects ask our engineers. Our typical response is “Yes,” followed by “...but doesn’t the owner want wireless in this building?” This somewhat facetious interrogative response is a way to open an important dialogue regarding the do’s and don’ts of locating Wireless Access Points on our projects. What Is Wireless LAN? It is best to start at the beginning in order to truly understand the operation of Wireless LAN data networking systems. As defined by Cisco, a Local Area Network (LAN) is “a collection of devices connected together in one physical location, such as a building, office, or home. A LAN can be small or large, ranging from a home network with one user to an enterprise network with thousands of users and devices in an office or school.” LANs have been designed into almost all commercial projects for more than 30 years. LAN connections have traditionally consisted of physical cabling run from the nearest Telecommunications Room (TR) on the floor to the end point device. Alternatively, a Wireless LAN (WLAN), though functioning similarly to this “wired” LAN, is defined by the obvious and not insignificant difference of utilizing radio waves rather than wired connections to facilitate communication between devices. The radio waves from each device are aggregated by the Wireless Access Point (“WAP” or “AP”) which connects to the LAN with physical cable(s). Therefore, the WAP can be thought of as a very expensive FM radio with antennas (either internal or external). When WAPs are installed above ceilings (accessible or hard), the FM radio signal is significantly diminished, which reduces both the signal range/coverage area of each device. Traditional Institute of Electrical and Electronics Engineers (IEEE) wireless transmission standards and equipment operate within the 2.4 or 5 GHz (Gigahertz) frequency band. The latest wireless

standards may additionally operate within the 6 GHz band. The higher the frequency, the less distance a signal can travel if obstructed by construction materials. Figure 8 on page 6 illustrates the latest Wi-Fi standards (from Wi-Fi 4 to Wi-Fi 7), their frequency bands of operation, and associated data rates (measured in Ethernet Protocol Megabits-per-second or Gigabits-per-second). Locating WAPs The Telecommunication Industry Association (TIA) provides structured cabling standards documents for the entire Information and Communications Technology (ICT) industry. In 2013, the TIA produced a document entitled TSB-162-A “Telecommunications Cabling Guidelines for Wireless Access Points.” Essentially, the guidelines provide direction on cabling between LAN equipment located in the local IDF, or Telecommunications Room, and WAPs. An update to this document is currently under development, but the basic recommendations are as follow: 1. Install twisted-pair Category 6A rated cabling to WAPs. This high bandwidth cable can prepare wireless networks for the next waves of WAP technology as data rates increase. 2. Use grid-based zone cabling architectures, with each cell in the grid no greater than 60 feet (18.3 meters wide. Basically, WAPs should be placed no further than a maximum of 60 feet apart. This distance requirement is likely to decrease as new WAPs utilize higher frequency signal transmission. Within commercial installations, the guidance provided under TSB-162-A is sufficient for most cabling designs. Additional Wireless Access Points may be added by the ICT design engineer to areas accommodating higher device quantities, such as large classrooms, lecture spaces, community rooms, and auditoriums. Each user may have multiple devices connecting to the WLAN including smartphones, laptops, tablet PCs, and


smart devices (smart watches, fitness trackers, etc.). Traditional (wired) LANs provide dedicated bandwidth to each device, while WLANs share bandwidth between devices. WAPs may interfere with each other if not configured correctly. Each WAP is limited in the maximum number of simultaneous data streams it can support. When an architecturally challenging situation is encountered, a more precise analysis may be required to determine WAP placement. At this point, a heat map study may be considered by the ICT design engineer. The study below provides a map of wireless signal coverage and strength within a facility. It takes into account the physical dimensions of the desired area and includes construction materials planned to help identify potential obstructions to the signal output. Heat map software fully automates the process of analyzing Wi-Fi coverage with its ability to import floor plans produced in industry-standard drafting software such as AutoCAD or Revit. Figure 5 - Heat Map Study

WAP Aesthetics WAPs come in many shapes, sizes, and form. Form factors differ between manufacturers. Some WAP units require external antennas in order to provide the required coverage of larger spaces or outdoor areas. As stated earlier, these devices simply do not work effectively when installed above ceilings or behind other partitions. Luckily, some manufacturers have developed solutions to better conceal these units and make their appearance more aesthetically pleasing. Interior space enclosures allow WAPs

“Wireless Access Points” continued from page 3

the ability to mount flush to the ceiling, revealing only the antenna face of the device for optimal wireless coverage. Manufacturers provide attractive, textured, powder-coated finishes to match many ceilings as shown below. Image 2 - Interior Wireless Access Point Ceiling Unit

Enclosures for outdoor spaces, such as the one illustrated in Image 3, are also available in many form factors including wall-mounted and free-standing bollards. These enclosures provide radio-frequency transparency to the WAPs located within. Image 3 - Outdoor Wireless Access Point Unit

Locating Wireless Access Points to achieve a successful wireless deployment is a process incorporating elements from both science and interior design. Determining what works best for each project should be a collaborative discussion between the ICT engineer and the project architect.

Women in Engineering In 2014, the Women’s Engineering Society (WES) launched the first ever Women in Engineering (WIE) Day on the 23rd of June to celebrate the 95th anniversary of the WES organization. Since then, the day has been observed all over the world by various institutions, academies, and organizations as a day to celebrate the growth and impact of women in the engineering discipline. This year, on June 23rd, Kohler Ronan also celebrated WEI by discussing its history, participating in round-table discussions, and distributing surveys to our female engineers regarding WIE topics. In this piece, we hope to provide a brief history of WIE, highlight relevant data points regarding women in engineering today, and share the results Kohler Ronan’s internal WIE survey. A Brief History According to the Society of Women Engineers (SWE), the first documented evidence of women in engineering dates back to 1876, when Elizabeth Bragg graduated from the University of California as a civil engineer. Although she was not a practicing engineer, her accomplishment was the steppingstone for a slew of women engineers who would follow in her footsteps. From 1876 until the 1900s, more and more women began enrolling, graduating, and participating in engineering careers— including making up for the male shortage in defense plants during World War II. Despite this presumed advancement for WIE, by 1972, the percentage of women holding degrees in engineering was only 0.2% in the United States. Women in Engineering Today Based on the Bureau of Labor Statistics, only 13% of active engineers in 2019 were women. That said, there are trends, according to the SWE, that indicate that the number of women holding bachelor’s degrees in engineering and computer science is increasing. In recent years, the organization has seen a 53% increase in such degrees over those obtained in 2011. Although “there are fewer women in engineering than any other profession: law, medicine and accounting,” as


mentioned in the SWE.org blog, these improvements are positive signs of the advancement of women in engineering and should not be discounted. They should serve as a roadmap for the future wave of female engineers. Women at KR As part of our effort to celebrate WIE day, Kohler Ronan distributed a survey to the women of the firm. The idea was to gain an understanding of how women in the company feel with regard to the WIE’s progress, where and how they believe improvements could be made, and what efforts could be provided to young women engineers to propel them into this rewarding profession in larger numbers. A summary of the questions and answers are below, beginning with KR’s WIE statistics at a glance:

REVIT® CORNER REVIT COLLABORATION The sheet copy plug-in has absorbed the best of

similar plug-ins and has become a great tool in the creation of sheets across many projects. Below are some of its capabilities and benefits. The plug-in allows the user to... •Create duplicates of specified sheets •Search on-the-fly from among the list of all sheets within a document •Copy sheets with and without species •Specify a prefix and suffix for names and sheet numbers •Utilize a unique numbering system that does not add an additional number if a unique leaf number is obtained with a prefix or suffix Finally, there are settings for copying views, legends, schedules, and much more!

“Women in Engineering” continued from page 4

• 50% of the engineering graduates hired in the past two years are female. • Women currently comprise 29% of the firm’s total staff. • 36% of the firm’s female engineers serve as Project Managers. • Women are represented within each of the firm’s engineering disciplines: mechanical, electrical, plumbing, fire protection, and technology. • 36% of our female engineers are LEED Accredited Professionals.

Top pieces of advice for young girls contemplating engineering as a career… • Join an engineering club organization at school • Apply for internships within the industry • Find a mentor • Advocate for yourself and have a voice • Support other females • Always continue learning Necessary attributes of a successful female engineer… • Confidence • Determination • Passion • Drive • Diligence

• Organization • Patience • Knowledge/Expertise • Willingness to learn continually • Effective communication • Flexibility

Do’s for young female engineers, do… • Explore every branch of engineering • Seek other female engineers at your school/company • Ask questions and participate often in discussions • Hone your skills by being part of engineering organizations • Be assertive • Make contacts in the industry • Know your worth

What inequities still exist for women as a whole in the engineering industry? • Lack of women in leadership positions across engineering companies • Lower pay across the industry What are the biggest opportunities for women engineers today? • Networking • Maximizing the support of fellow female engineers • Growing realization that women make significant contributions to project teams • The growing belief that female voices are finally being heard and acknowledged

Don’ts for young female engineers, don’t….. • Question if you belong • Be shy to ask questions or seek help • Settle with small acts of exclusion • Be afraid to speak up • Worry if you have bumps along the road; challenges can be learning experiences • Accept things that you do not agree with • Doubt yourself • Avoid challenges Do females bring a unique or different outlook or approach to project design? • Everyone brings a different outlook or approach to projects. • Engineering affects everyone and, therefore, the field should reflect society as a whole. • It is important to have different perspectives, male and female, in all areas of design work. • Women bring another level of diversity which benefits all projects. What are the biggest challenges women face in the industry today? • Obtaining leadership roles • Maintaining a work/life balance • Lack of confidence


What progress have you witnessed in the industry relative to women’s inclusion and advancement over your career to date? • There are increasing numbers of women in the industry. • Women are leading projects in growing numbers across the AEC professions. • More women are assuming leadership roles within their respective firms.

“Covid-19: Systems Design” continued from page 2

thought to destroy viruses’ DNA bonds. • Flexible applications for new units, existing units, and retro-fit applications include in-duct air disinfection, upper-air disinfection, in-duct air surface disinfection, and portable room decontamination. See Figure 6. Figure 6 - In-Duct Air Disinfection

Bipolar Ionization Bipolar ionization technology releases charged atoms that attach to and deactivate harmful substances like bacteria, mold, allergens, and viruses. The technology has already proven effective against SARS, norovirus, and several influenza strains. That said, Bipolar Ionization systems are reported to range from ineffective to very effective in reducing airborne particulates and acute health symptoms. Figure 7 - Bipolar Ionization

According to the American Society of Heating, Refridgerating, and AirConditioning (ASHRAE), convincing, scientifically-rigorous, and peer-reviewed studies do not currently exist on this

emerging technology. As recommended by ASHRAE, manufacturer data should be carefully considered. How Do You Get There? Evaluating the options for improved air quality may seem overwhelming. It is helpful to start by understanding how spaces in your building are served and where the greatest need is. Where existing central HVAC equipment is installed, evaluate it for the criteria listed throughout this article. It is encouraging to note that some simple improvements can make existing HVAC systems much more effective. Technologies for air quality improvement can be applied to almost any HVAC system and, if none exist, retrofit systems and/or portable units can be installed. Creating an engineered plan for improvement is highly advised. In summation, HVAC improvements can permanently improve a building’s air quality and, perhaps more importantly, the lives of the people who occupy those buildings.

Figure 8 – Difference from Wi-Fi 4 to Wi-Fi 7

Traditional Name

Wi-Fi 4

Wi-Fi 5

Wi-Fi 6




Wi-Fi Alliance Certification Mark Bands

Data Rates (Theoretical Maximum) Spatial Streams Beamforming Cabling Requirements

802.11be TBD

2.4 or 5 GHz

5 GHz only

2, 4, and 5 GHz Compatible with 6 GHz range

2.4, 5, and 6 GHz

576 Mbps

6933 Mbps

9607.8 Mbps

> 10 Gbps


8 (unlikely to exceed 4)







Category 6

Category 6A

Category 6A

2x Category 6A

No restrictions w/802.3at PoE+



No restrictions w/802.3bt PoE++

2x Category 6A

PoE Requirements (Full Features Access No restrictions Point) w/802.3af PoE PoE Requirements (Enhanced Features Access Point)

Wi-Fi 7

Note: 1) Restrictions are user programmable in Intelligent Power Management (IPM) enabled WAPs. 2) An enhanced featured access point is targeted for very high-density environments like large public venues, hotels, and enterprise offices where the optional features within the access point are enabled to support this type of setting. 6

Project Highlight — National Purple Heart Hall of Honor

Renderings Courtesy of ikon.5 architects Dedicated to honoring approximately 1.8 million American military personnel who have lost their lives or have been wounded by enemy action, the National Purple Heart Hall of Honor was opened in 2006 to celebrate these brave recipients of the Purple Heart. Located in New Windsor, NY, not far from Washington’s Headquarters State Historic Site in

Newburgh, the museum is currently undergoing a significant expansion of 4,300 square feet. The project’s goal is to better highlight the personal stories of each recipient via integrated audio-visual presentations, effective lighting, interactive exhibits, museumquality casework housing wartime artifacts, and substantial, large-scale

graphic displays. In collaboration with ikon.5, Kohler Ronan is proud to have designed comprehensive Mechanical, Electrical Plumbing, and Fire Protection systems for this very special space. The National Purple Heart Museum is currently under construction and is slated for completion later this year.

Fig. 4 - Semmelhack, John. (2020, April 10). Can Your HVAC System Filter Out Coronavirus?. [Chart]. Retrieved Aug. 19, 2020 from https://www.energyvanguard.com/ blog/can-your-hvac-system-filter-out-coronavirus

Fig. 7 - Horning, Andrew B. (2020, May 6). COVID-19 and the impacts to the workplace. [Graphic]. Retrieved Sept. 2, 2020 from https://www.csemag.com/articles/ covid-19-and-the-impacts-to-the-workplace/

Fig. 5 - Wilson, Marc. (2019, June 6). Wifi Heat Map Software & Tools for Site Surveying and Troubleshooting Wireless Networks. [Graphic]. Retrieved Sept. 3, 2020 from https://www.pcwdld.com/wifi-heat-map-softwaretools

Figure 8 – Difference from Wi-Fi 4 to Wi-Fi 7. [Chart]. Retrieved Sept. 2, 2020 from Panduit White Paper “Wi-Fi 5, 6, and 7: Insights and Impacts on Cabling Infrastructure.”

Figure & Image Credit Fig. 1 - (2020). No more Particles, Allergens & Contaminants in the Air. [Graphic]. Retrieved from https://sanuvox.com/product/s300/ Fig. 2 - Ben Guida, D.. (2019). Heat Recovery Ventilation for Energy-Efficient Buildings: Design, Operation and Maintenance. 9. 3713-3715. Retrieved from https:// www.researchgate.net/figure/Optimum-relativehumidity-range-for-minimizing-adverse-health-effects_ fig4_337289756 Fig. 3 - (2020). Aprilaire 865 Ductless Steam Humidification Package with Digital Control. [Graphic]. Retrieved Sept. 16, 2020 from https://www. totalhomesupply.com/p/aprilaire-865-ductless-steamhumidification-package-with-digital-control

Fig. 6 - Woerpel, Herb. (2015, February 23). UV and Air Purification Effectively Contain Airborne Pathogens. [Graphic]. Retrieved Aug. 19, 2020 from https://www. achrnews.com/articles/128955-uv-and-air-purificationeffectively-contain-airborne-pathogens

Images 2 & 3 - (2020). eAccu-Tech: Exceeding the Demands of Your Network. [Iamges]. Retrieved May 28, 2020 from http://www.eaccu-tech.com/in-buildingwireless/wireless-access-point-enclosures/1047-lpdomesuspended-ceiling-mount-aruba-networks-ap-oberon/

About the Firm From our offices in Danbury, Connecticut and New York, New York, our team of approximately 70 professionals collaborates with prominent architectural firms on a wide array of regional and nationally recognized project assignments. Commissions include those for world-renowned museums, fine and performing arts centers, prestigious universities, state-of-the-art educational and healthcare facilities, luxury residences, and premier recreation establishments. Additionally, we have the privilege of designing specialty systems for landmark sites and historically significant buildings across the country. For more information, please visit our website at kohlerronan.com or connect with us on social media.


New York 171 Madison Avenue, New York, NY 10016 T 212.695.2422 Danbury 93 Lake Avenue, Danbury, CT 06810 T 203.778.1017 Connect kohlerronan.com marketing@kohlerronan.com

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Fall 2020, Vision Issue 11: Covid-19 Systems Design  

Fall 2020, Vision Issue 11: Covid-19 Systems Design  

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