Chris Muller, ASHRAE Distinguished Lecturer Technical Director Purafil, Inc., Doraville, Georgia

1. The Role of Filtration and Air Cleaning in Sustaining Acceptable IAQ through Ventilation Replacement Chris Muller, ASHRAE Distinguished Lecturer Technical Director Purafil, Inc., Doraville, Georgia

2. Introduction • The use of air cleaning for contaminant control as a substitution for ventilation has been an accepted practice since the energy concerns of the early 1970s. • It has been an acceptable alternate method for attaining acceptable indoor air quality (IAQ) within established ventilation standards since the publication of ASHRAE Standard 62-1981. • Even though this technique provides significant savings in capital equipment and operating costs, widespread use of this practice has been limited because of engineering and commissioning requirements and the lack of documented energy usage results.

3. Introduction (cont.) • The interest in filtration and gaseous air cleaning applications has been revitalized for a number of reasons, such as the following: • The Aging Building Population. • Energy Management and Conservation. • Heightened Awareness of IAQ Concerns by Occupants. • Re-issuance of Standard 62.1 and Related Addenda. • Emergence of New Standards of Care. • Green Building and Sustainability Initiatives. • The Threat of Potential or Real Vulnerability of the Building Stock to Airborne Weapons of Mass Destruction (WMD).

4. Introduction (cont.) • Studies report higher ventilation rates improve workers’ and students’ health, productivity, and learning. • Higher ventilation rates come with a significant energy penalty. • Opposes current trend for sustainable, greener buildings. • Require higher energy efficiency levels to meet guidelines • Higher ventilation rates are too costly as energy costs rise. • Outdoor air in many area has elevated pollution levels. • Using ASHRAE 62.1 IAQ Procedure and employing gas-phase filtration combined with particulate filtration is a solution to optimizing the indoor air quality without raising ventilation rates.

5. The IAQ Procedure: What? ASHRAE Standard 62.1 Performance Pathway The IAQ Procedure (IAQP) employs alternate contaminant control tactics to substitute for and lessen amounts of outdoor ventilation air to lower cost, energy usage, and building or occupant exposure to potentially harmful contaminants from indoor and outdoor sources.

6. The IAQ Procedure: Why? Because Outdoor Air is Neither Clean nor “Fresh”

7. The IAQ Procedure: Why?

8. Project Scope – Phase I • Acquisition of field performance data on existing filtration and air cleaning systems (FACS). • Determination of the contaminants of concern (CoCs) in urban outdoor air and indoor environments of commercial buildings. • Comparison of identified acceptable IAQ profile (Class 1 air) with air treated using enhanced air filtration. • Quantification of energy savings through the use of enhanced air filtration.

9. Project Scope – Phase I (cont.) • Field study was performed for evaluation and analysis of 7 commercial buildings providing15 individual study sites. • Variety of building styles representing cross-section of commercial facilities. • All buildings had enhanced air filtration systems. • Each site was checked for outdoor air quality, performance of the air cleaning system, and the contaminant levels in the occupied space. • Included testing and analysis of particulate matter, airborne microbial constituents, and chemical content of the air.

10. Project Scope – Phase II • Location: Atlanta GA and environs • Code acceptance in 1981 • Ambient psychrometric conditions • Contamination level of O/A • Measured effectiveness of enhanced air filtration systems to remove airborne contaminants at all 15 sites • Measured operational cost savings and payback over time at 11 of the 15 sites from Phase I. • Results to provide scientific documentation of the performance of air cleaning equipment as an addition to and/or potential alternative to the use of O/A for dilution of airborne contaminants and control of IAQ.

11. Phase II - Methodology • Building Types • Archival Storage Facility (sites 1 & 2) • High Occupancy Sports Arena (sites 3 & 4) • University Hotel and Conference Center (site 5) • High-Rise Atrium Hotel (sites 6-9) • Low-Rise Atrium Hotel (sites 10 & 11) • Specialty Museum (sites 12 & 13) • Office Building (sites 14 & 15)

12. Evaluation Protocol • Particulate filtration efficiency • Particle counts (#/ft3) • Viable particle counts (CFU/m3) • Gas-phase air cleaner efficiency • VOCs (tube collection/GCMS evaluation) • Acid Gases • Ozone • Carbon dioxide (monitor)

13. Evaluation Protocol • Return air upstream of FACS • Supply air downstream of FACS • Outdoor air independent of R/A • Duplicate/multiple samples • Data yield: • FAC efficiency = upstream vs. downstream • System efficiency = inside vs. outside • Financial analysis of energy cost savings

14. Phase II - Methodology • On-site monitoring was performed at all sites. • Total and individual volatile organic compounds. • Acid gases (sulfur dioxide, nitrogen oxides, hydrogen sulfide). • Ozone • Carbon dioxide • Particles (both viable and total). • Measurements were taken upstream and downstream of the filtration systems and in the outdoor air. • Financial analysis was performed for energy cost savings when using IAQ Procedure (reduced outdoor air ventilation rates) versus Ventilation Rate Procedure (outdoor air for dilution of contaminants).

15. Sites 1 & 2 – Archives

16. SiteS 1 & 2 – Archives • Located near x-ways, industry, & airport • Long term storage of delicate documents vulnerable to O/A acid gases and oxidants • Separate O/A FAC and return/supply air systems augmented with dehumidification • Installed FAC: • MERV 6 prefilters • HEPA cartridge final filters • High Efficiency solid bed sorption filters with blend of active carbon and KMnO4 pellets

17. Sites 3 & 4 – Sports Arena

18. Sites 3 & 4 – Sports Arena

19. Sites 3 & 4 – Sports Arena • Adjacent to rail, x-way, parking garage • Large density (80,000) & diversity • Employed IAQP @ 1991 construction • FAC Installed: • MERV 6 prefilters • MERV 13 pocket filters • Energetic control system • Medium efficiency gas phase (intervention)

20. Site 5 – HOTEL Conference Center

21. Site 5 – Hotel Conference Center

22. SITE 5: Hotel Conference Center

23. Site 5 – Hotel Conference Center • Urban location with high traffic • Food odor contaminated outdoor air • FAC installed to treat poor O/A • Intent to recycle building exhaust • FAC Installed: • MERV 13 minipleat cartridge • Deep bed high capacity sorbent cartridges

24. Sites 6-9 - High-rise atrium hotel

25. Sites 6-9 – High-rise atrium hotel

26. Sites 6-9 – High-rise atrium hotel

27. Sites 6-9 – High-rise atrium hotel • Aging hotel with atrium heat/capacity issues • Retrofitted 4 FAC systems, two with cooling • Recycled 80,000CFM & reduced ventilation air • FAC installed: • MERV 13 cartridge particulate filters • Deep bed gas phase filters with dual media • MERV 6 pre & post filters

28. Sites 10 & 11 – Low-rise Atrium Hotel

29. Sites 10 & 11 – Low-rise Atrium Hotel

30. Sites 10 & 11 – Low-rise Atrium Hotel • Retrofit FAC to treat exhaust from lobby conference center and related toilets • Two 6000cfm FAC units with fan • FAC Installed: • MERV 6 pre-filters • MERV 14 rigid cartridge filters • Deep bed high efficiency sorbent modules

31. Site 12 & 13 – Specialty Museum

32. Site 12 & 13 – Specialty Museum • Suburban location remote from city • Specialty museum restoration and storage facility • Subject to both to outdoor ambient oxidants and indoor generated VCO • FAC installed: • MERV 6 prefilters • Deep bed gas phase air sorbent modules • MERV 14 high efficiency rigid cartridges

33. Sites 14 & 15 – Office Tower

34. Sites 14 & 15 – Office Tower

35. Sites 14 & 15 – Office Tower • Aged office tower facing tenant demands for current code application • Aged mechanical equipment with poor access for service or replacement • Upgrade to 62.1-04 using medium efficiency combined filter/gas cleaner • FAC installed • Combined medium efficiency sorbent pleat with MERV 8 particulate efficiency

36. Results and Discussion • Particulate Contaminant Control - removal efficiency @0.5 micron through air filtration systems (site avg.).

37. Results and Discussion (cont.) • Gaseous Contaminant Control - reductions in VOC & particulate concentrations were observed at all sampled sites (comparing upstream versus downstream concentrations).

38. Results and Discussion (cont.) • Gaseous Contaminant Control - Significant reductions in majority of specific VOCs at all sites when comparing upstream vs. downstream concentrations. • Source of many VOCs assumed to be from cleaning products.

39. Results and Discussion (cont.) • Ozone was removed completely (100%) by the gas-phase filters at each site in each building. • Acid gases (e.g., sulfur dioxide, SO2; nitrogen dioxide, NO2; hydrogen sulfide, H2S) were only detected at low concentrations in outdoor and indoor air at any sampling site. • The reduction in total particle counts for 0.5 µm and larger particles ranged from 28-95%.

40. HVAC Operational Cost (Energy) Savings • Energy cost savings analysis was performed comparing the use of lower outdoor air ventilation rates with enhanced air filtration using the IAQ Procedure versus simple dilution using the Ventilation Rate Procedure. • The sports arena had the most dramatic savings of any of the buildings due to the size of the facility as well as the amount of ventilation air required. • Reduced chiller capacity by 2,350 tons and saved US$2.5 million in construction costs. • Reduced heating requirements by forty million BTU resulting in a US$800,000/year energy costs savings. • This facility continues to realize a net energy saving of more than US$1,300,000/year. In fact, the accumulated savings are greater than original building cost!

41. HVAC Operational Cost (Energy) Savings (cont.) • The annual net energy savings costs for the other study buildings ranged from US$9,662-$105,101/year over and above the cost for the filter replacement and maintenance at the time these buildings were first occupied.

42. The IAQ Procedure: When? • Optimal conditions include: • Outdoor air is hot and humid. • Non-attainment for one or more criteria pollutants. • Enhanced air cleaning is already employed for other reasons. • CoCs are known and are present at elevated concentrations. • Target concentrations for CoCs are known. • Components and materials selected for low VOC emissions. • When the VRP requires supplemental ventilation. • Successful experience with similar sites. • High population and wide density diversity.

43. The IAQ Procedure: When? • Optimal conditions include (cont.): • Renovation of existing property that may require higher outdoor ventilation rates for code compliance. • Properties that are at or near the heating and cooling capacity limits with existing HVAC systems. • The facility has room available for retrofit with enhanced air cleaning – both particulate and gaseous filtration. • There is a motivated and knowledgeable building owner. Design of new or renovation of existing buildings with LEED certification as a goal.

44. The IAQ Procedure: Why? • Summary of Benefits: • Reduces exposure to polluted outdoor air. • Avoids excessive latent heat load from outdoor air. • Allows reduced capacity of all components (CAPEX). • Reduces energy requirements (OPEX). • Enhances life cycle cost of building. • Enhances indoor air quality and sustainability through direct controlof airborne pollutants.

45. The IAQ Procedure: Why? • Summary of Benefits (cont.): • Improves system cleanliness. • Improves moisture and humidity control. • Lowers risk of airborne pathogens and related disease. • Improved productivity and morale. • Enables cost effective increases in ventilation to meet sustainability needs. Because it makes sense and turns “sustainability” from a goal into reality with dollars and ¢ents!

46. Summary and Conclusions • Previous research has established the useful role of particulate filtration in keeping HVAC systems clean. • All of the study buildings were retrofitted with enhanced filtration systems. • Measureable and significant reduction in particulates >0.5 µm, TVOCs, and ozone. • Annualized operational cost savings ranging from US$10,000 - US$1,300,000 over and above the cost of filters and maintenance. • Produced data on selection of the contaminants of concern (CoCs) which can guide users of the IAQ Procedure.

47. Summary and Conclusions (cont.) • In areas with poor outdoor air quality, focusing on fine particulates, ozone, and VOCs can be useful in building and HVAC system design process. • This study clearly demonstrates that the IAQ Procedure from ASHRAE Standard 62.1 can be effectively applied to buildings and improve the indoor air quality and reduce operating costs, particularly as a retrofit option to existing buildings. • The indoor air pollutants were clearly reduced when compared to those in the outdoor air thus validating the applicability of the IAQ Procedure.

48. Acknowledgements • This project was sponsored by a consortium of local and national firms that made the effort possible with financial support and in-kind contribution of equipment and services. • We gratefully acknowledge funding for this research from: • Kimberly-Clark Company• Purafil, Inc. • Alfred P. Sloan Foundation • Indoor Air Quality Association • Building Wellness Consultancy, Inc. • In-kind contributions were furnished by: • Filtration Group • McKenney's, Inc. • AirEnergy, Inc. • Purafil, Inc.

49. THANK YOU FOR YOUR ATTENTION! • Copies of the final reports for Phase I and Phase II of this project including full descriptions of the study sites, air filtration systems, and test data may be obtained through a written request to the author. QUESTIONS? Contact Information: Chris Muller cmuller@purafil.com +1-770-825-7341