Air Date: 10-14-2016| Episode: 434
This week on IAQ Radio we welcome Penn State Professor and ASHRAE Past President William P. Bahnfleth, Ph.D., P.E. We last interviewed Dr. Bahnfleth in July of 2015 on Episode 335…
This week on IAQ Radio we welcome Penn State Professor and ASHRAE Past President William P. Bahnfleth, Ph.D., P.E. We last interviewed Dr. Bahnfleth in July of 2015 on Episode 335. Our first interview was not not long after the ASHRAE, IAQA merger and we spent a good bit of time on that topic. This time around we want to discuss some highlights from the recent ASHRAE IAQ 2016 Conference and Dr. Bahnfleths extensive knowledge and research on UVGI. We also want to discuss the IEQ Global Alliance and of course how things are look over a year into the ASHRAE, IAQA merger. Bill Bahnfleth is a professor and director of the Indoor Environment Center in the Department of Architectural Engineering at The Pennsylvania State University-University Park. He holds a doctorate in Mechanical Engineering from the University of Illinois at Urbana-Champaign and is a Registered Professional Engineer. He has more than 30 years of experience as a consulting engineer, researcher and educator. Dr. Bahnfleth has been a member of ASHRAE since 1981 and in addition to being Past President he is an ASHRAE Fellow and Distinguished Lecturer.
ASHRAE IEQ Conference Highlights, UVGI Research to Practice & Association Watch!
This week on IAQ Radio we welcomed Penn State Professor and ASHRAE Past President William P. Bahnfleth, Ph.D., P.E. Dr. Bahnfleth is a professor and director of the Indoor Environment Center in the Department of Architectural Engineering at The Pennsylvania State University-University Park.. He has more than 30 years of experience as a consulting engineer, researcher and educator. Dr. Bahnfleth has been a member of ASHRAE since 1981 and in addition to being Past President he is an ASHRAE Fellow and Distinguished Lecturer.
We last spoke to Bill on 7-25-15 Episode 335 not long after the ASHRAE, IAQA merger. Today we discussed with him: the recent ASHRAE IEQ Conference, his UVGI research, The IEQ Global Alliance and how things look to Bill one year into the ASHRAE, IAQA deal.
Nuggets mined from today’s interview:
Please give listeners your thoughts on the direction of government IAQ policies?
Government agencies can help to promote science-based uniform standards in the way that, for example, DOE has done with respect to energy standards for buildings by supporting the development of ASHRAE Standard 90.1 and making it the national non-residential code basis. While regrettably much good research isn’t making it into standards the government also assists by providing funding for fundamental and transitional research.
What agencies of than EPA are dealing with IAQ related issues?
The list of participants in the Federal Interagency Committee on Indoor Air Quality (CIAQ) gives a good idea of how many agencies are concerned with IAQ in some way. DOE, DOD, GSA, OSHA, NIOSH, HUD, and many others. https://www.epa.gov/indoor-air-quality-iaq/federal-interagency-committee-indoor-air-quality.
Does EPA plan to make better use of their ability to regulate outdoor pollution to help with indoor pollution?
Government regulatory activities are focused on identifying and removing hazardous sources (e.g., known carcinogens). The main consequence of major outdoor environmental issues is indoor pollution, as in sites remediated under the Superfund.
IAQ 2016 Conference Highlights
“This conference provided guidance to researchers, experts, policy makers, building owners and operators, engineers, designers, IAQ professionals, commissioning agents, architects and other interested participants about what works and what really doesn’t work when tackling major improvements in indoor air quality. Target facilities include residential and non-residential buildings.”
We’re moving from “perceived air quality” standards (i.e., based on subjective perception) towards standards based on health and performance.
Metrics are needed to support more advanced definitions of IAQ and we’re not sure yet what to measure or control. Conference participants voted metric development as the #1 priority in the field today.
The conference provided a unique opportunity for dialog among attendees to facilitate understanding of current indoor air quality policies, standards and best practices with themes such as regulatory vs. voluntary compliance for achieving IAQ.
The role of IAQ in sustainable building programs.
Examining IAQ outcomes from a real estate property portfolio perspective.
Sampling alone is not as effective as we think.
Building investigation by experts is generally more valuable than measurements.
Keynote speaker Dave Jacobs (National Center for Healthy Housing)- Home IAQ is central to the healthcare cost crisis. A $1 investment in asthma source control in homes saves $5-$14 in healthcare costs.
Weatherization + ASHRAE Standard 62.2 compliance found to improve home IAQ.
Reactive IAQ – responding to problems rather than proactively preventing them. Example – recently discovered dangers of exposure to diacetyl from coffee roasting http://www.seattletimes.com/nation-world/coffee-bean-fumes-deemed-hazardous-to-workers-health/
UVGI Research to Practice Questions
Please comment on UV light disinfection significantly reducing Clostridium difficile incidence. https://www.sciencedaily.com/releases/2016/10/161006120507.htm
The device tested is one of the class of UVGI room disinfection units. Studies on this application go back nearly 10 years. Others have found significant reduction in MRSA on surfaces as well as of c. difficile. If there is a real difference in effectiveness, the two most likely possible causes are 1) MRSA is more resistant to UVC than c. difficile (literature does not give definitive values of UV rate constant for either).; 2) ankeymode of transmission is not affected much by cleaning surfaces. For example, if I completely disinfect surfaces in a room of the Ebola virus, that does not protect me against the primary mode of transmission, which is direct contact with bodily fluids – blood, etc. – from an infected individual. C. difficile is found in feces and is transmitted in a healthcare setting by transfer from contaminated surface to patient by healthcare personnel. MRSA is also transmitted by such contact, but may also be transmitted from an infected individual to a susceptible one, so transmission is not as dependent on the existence of contaminated surfaces (source: CDC).Multiple studies show that UVGI reduces MRSA populations on surfaces, but without investigating the effect on infection rates.
Added comment from Bill:
Differences in measured concentrations on surfaces or in air do not necessarily equate to proportionate differences in clinical outcome.
Disinfection Performance of an Ultraviolet Coil Irradiation System in a Hot and Humid Climate
In a hot and humid climate, the year-round wetting of cooling coils and drain pans make them ideal breeding grounds for microorganisms, which may have adverse effects on indoor air quality (IAQ) and cause fouling of coils that increases HVAC system energy use. Ultraviolet coil irradiation systems are marketed on the basis of claims that they will improve coil performance, save energy and improve IAQ. The disinfection performance of a coil irradiation system was investigated via a field study. A commercially available coil irradiation system was installed on the downstream side of a cooling coil in a variable air volume (VAV) air handling unit (AHU) serving a library building. The disinfection performance was assessed by a “before” and “after” irradiation comparison of bio-contamination level on coil surfaces. Surface biological samples were collected from both upstream and downstream side coil fin surfaces based on a 2 × 3 sampling grid using spear shaped absorbent swabs. Seven samplings were conducted (two before irradiation and five after irradiation) throughout the study. The measurements taken showed that 1) the coil irradiation system is able to rapidly eliminate fungi on downstream coil surfaces; 2) 10 weeks may not adequate to disinfect upstream coil surfaces; 3) the coil under investigation is mainly contaminated by fungi during normal operation with heavier fungal contamination occurring on upstream coil surfaces. The above observations suggest that coil irradiation systems may be effective in disinfecting coil surfaces in a hot and humid climate.
Added points from Bill:
Using UV coil irradiation is now popular and well accepted.
Has shown an increase in biofouling removal.
Lamps when installed upstream from the coil may be2X more energy efficient due to differences in air temperature.
Lamps when installed downstream from the coil keep condensate pans clean.
Lamps should be periodically cleaned and replaced annually.
Modeling Monetization of Collateral IAQ Improvements from UVGI for Coil Cleaning
Ultraviolet Germicidal Irradiation (UVGI) of cooling coils is done to control biofouling that can increase their flow resistance and decrease their heat transfer coefficient. UVGI is also applied in air-handling units to improve indoor air quality (IAQ) by deactivating airborne microorganisms. A typical coil cleaning application delivers a smaller UV dose than an air treatment system, but should provide some collateral air treatment benefit. To date, this effect has not been studied. In this investigation, the benefit of air treatment provided by a cooling coil irradiation system is estimated via simulations employing a subset of the DOE Commercial Reference Buildings library. Benefits were quantified in terms of changes in appropriate measures for each building type: work-loss days (WLD) for office buildings, disability adjusted life years (DALY) for schools, and hospital acquired infections (HAI) for healthcare facilities. UVGI sized for coil cleaning results in a 0% to 7% average reduction in the measure of interest for each building type. This reduction is negatively related to the average outdoor air fraction in each building type, i.e., incremental benefit of UVGI decreases with increasing outdoor air fraction. Combining WLDs with US Gross National Income to monetize annual savings for office buildings yields $0.22/m2 – $3.11/m2 for Small, $0.12/m2 – $0.91/m2 for Medium, and $0.01/m2 – $0.23/m2 for Large types. Combining DALYs with US Gross National Income to monetize savings for Primary and Secondary Schools results in a wide range: $0.00/m2 to $0.62/m2 due to the large range of values one might reasonably assign to a DALY. In hospitals, reduction in airborne HAIs resulted in estimated savings of $0.05/m2 to $0.40/m2.
Added points from Bill:
Measurements and modeling are being done in Central PA, Tampa, FL and Singapore
UV lights only cost 20% of alternative maintenance
Energy savings attributed to UV lights are 20% decrease in pressure drop across coil and 15% increase in heat transfer coefficient. While financial savings are small, UV lights can be cost-effective and extend the life cycle of coils.
The IEQ Global Alliance (http://ieq-ga.net/), is an association of associations concerned all aspects of indoor environmental quality – air quality, thermal environment, lighting, and acoustics. The objectives of the group are to about determining what needs done to stimulate progress and to project consistent messages to promote it, including, communication with the public, and advocacy. The program has several years additional funding to help it get established.
IAQA and ASHRAE
How is the merger of these two groups going from your perspective as an ASHRAE Past President and the one that helped forge this relationship?
Good progress but more to be done, ironing out management and staffing issues came first, now must focus on collaboration. Coordinating meetings in same venues in January is an important step forward. IAQA now taking a more global view – has opened new chapters in India and Shanghai recently. Looks forward to a synergistic relationship with ASHRAE doing research, education, publications relevant to IAQA’s practitioners.
Is there anything you would like to add?
Improve awareness of IAQ at higher levels and push science into practice.
“Penn State Official Fight Song – YouTube
Z-Man signing off
Name the bone strengthening vitamin in humans and other vertebrates that ultraviolet light is responsible for forming?