Cannon Design's John Swift delivered this presentation at the 2011 Labs21 conference.

1. Utilizing Energy Recovery and Optimizing Air
Exchange Rates in Laboratory Buildings to Achieve
Optimal Energy and Air Quality Results
John Swift, Jr., PE, LEED, CEM
Principal- Cannon Design
Boston, MA
Labs21 2011 Annual Conference
Providence, RI

2. Labs 21 is a Registered Provider with The American Institute of
Architects Continuing Education Systems. Credit earned on completion
of this program will be reported to CES Records for AIA members.
Certificates of Completion for non-AIA members are available on
request.
This program is registered with the AIA/CES for continuing professional
education. As such, it does not include content that may be deemed or
construed to be an approval or endorsement by the AIA of any material
of construction or any method or manner of handling, using, distributing,
or dealing in any material or product. Questions related to specific
materials, methods, and services will be addressed at the conclusion of
this presentation.

3. This presentation is protected by US and International
Copyright laws. Reproduction, distribution, display and use of
the presentation without written permission of the speaker is
prohibited.
© Cannon Design, 2011

4. Learning Objectives:
Learning objective 1: Understand current air exchange
recommendations in lab spaces looking at OSHA, ASHRAE and
NFPA standards.
Learning objective 2: Understand the benefits and challenges of
applying desiccant energy wheels for manifolded, central air handling
systems serving laboratory buildings.
Learning objective 3: Understand the benefits of dilution
assessments, dynamic air monitoring systems and MERV 16
filtration.

5. Overview
The presentation will discuss the
positive energy reduction impact
of reducing air changes in
laboratory spaces while
maintaining safe and healthy
indoor air quality levels for the
building occupants.

6. Design Process
Designing Critical Duty Projects
Requires a Rigorous Process

7. Air Exchange Rates in Laboratory Buildings
• Health
• Safety
• Protect Research
• Comfort
• Efficient Use of Resources

8. Air Exchange Rates in Laboratory Buildings
Health and Safety
• Safe Operating Practices
• Emergency Equipment
• Air Quality
• Air Changes

9. Air Exchange Rates in Laboratory Buildings
Protect Research
• Air Quality
• Redundancy

10. Air Exchange Rates in Laboratory Buildings
Comfort
• Optimize Indoor
Environmental Quality
• Indoor Air Quality
• Natural and Artificial Light
• Thermal Comfort

11. Air Exchange Rates in Laboratory Buildings
Efficient Use of Resources
• High Performance Design
• Energy Efficient Building Systems
• Ease of Maintenance and Service

12. Air Exchange Rates in Laboratory Buildings
Source Air Changes per hour
NFPA 45- 2000 8 ACH occupied, 4 ACH
unoccupied
NFPA 45-2011 No min/max
ASHRAE- 2007 Handbook 6 – 12 ACH*
and Lab Design Guide
OSHA 1910 4 – 12 ACH
NIH Guidelines 6 ACH

13. Air Exchange Rates in Laboratory Buildings
• No codes- just guidelines
• No standard industry practice
• Higher ACH do not assure optimized
Ventilation Effectiveness

14. Air Exchange Rates in Laboratory Buildings
Factors in Determining Optimized Rate
• Cooling Loads- External and Internal
• Exhaust Make-up Requirements
• Ventilation for Optimized Air Quality

15. Air Exchange Rates in Laboratory Buildings
Ventilation for Optimized Air Quality
• Model-based design process
• Computational Fluid Dynamics (CFD)
• Optimize air flow to maximize ventilation
effectiveness
• Measure and provide dynamic ACH control
• Eliminate turbulence at fume hoods and bio-
safety cabinets

16. Energy Wheels
2-3. Outdoor Air is
Cooled, Dehumidified then
How It Works: Supplied to HVAC System
(Cooling)
4. Exhaust Air is
Pulled from the Space
1. Fresh Outdoor (Cool and Dry)
Air (Hot and Humid) is
Passed Through the Wheel
5-6. Exhaust Air is Heated and
Humidified then Sent Outdoors

17. Energy Wheels
TYPICAL PERFORMANCE
BUFFERS SPACE FROM EXTREME OUTDOOR AIR CONDITIONS
Exhaust Air Return Air Exhaust Air Return Air
90 DEG 75 DEG 18 DEG 72 DEG
105 GR. 60 GR. 11 GR. 32 GR.
95 DEG 80 DEG 0 DEG 54 DEG
120 GR. 75 GR. 4 GR. 25 GR.
Outdoor Air Supply Air Outdoor Air Supply Air
Cooling Mode Heating Mode

18. Energy Wheels
Function of the Purge Section
• Purge dirty air trapped in wheel media as it
rotates from the dirty to the clean airstream
• Purge angle adjustable and driven by the
pressure differential existing between the
outdoor air and return air streams
• Proper setting shown to limit carry-over to well
below .045% in actual field commissioning tests

19. Energy Wheels
Codes: Energy Wheels in Laboratories
NFPA 45 requires documentation (test data and field experience) that exhausted
contaminants are not transferred by the total energy recovery wheel.
“Devices that could result in recirculation of exhaust air or exhausted
contaminants shall not be used”
IBC 2006 and 2009
Laboratories are not considered hazardous exhaust systems if contaminants
are below 25% of flammability limit and below 1% medial lethal
concentration (lab assessment analysis)
Duct systems can be manifolded and wheels used if contaminants are not
recirculated
References 90.1 which recommends total energy (>50% total energy recovery)

20. ASHRAE Standard 62
Purpose:
To specify the minimum ventilation rates
and indoor air quality that will be
acceptable to human occupants and are
intended to minimize the potential for
adverse health effects.

21. Energy Wheels
Codes: Energy Wheels in Laboratories
ASHRAE:
In a recent interpretation of ASHRAE 62.1-2007, has indicated that mandatory
section 5.16.3.4 “does not allow for recirculation of any amount of Class 4 air nor
does it allow the use of heat recovery equipment which will result in recirculation of
Class 4 air via leakage, carryover or transfer from the exhaust side of the system.
It is possible to install heat recovery equipment, such as run-around loops, heat
pipes or impermeable, plate-type heat exchangers, which will allow heat recovery
from the Class 4 exhaust airstream while preventing cross-contaminated flow.”

22. Energy Wheels
Codes: Energy Wheels in Laboratories
ASHRAE
Fume hood exhaust air is generally classified as Class 4 air by ASHRAE 62.1-
2007. Since this section is a mandatory requirement of ASHRAE 62.1-2007,
non-compliance would mean that the design does not meet the LEED
prerequisite for compliance with ASHRAE 62.1-2007 which means the project
could NOT be LEED certified. Project design teams will need to indicate how
they will address compliance with ASHRAE 62.1-2007 while taking manifold
fume hood exhaust air through proposed enthalpy wheels.

23. Energy Wheels
Codes: Energy Wheels in Laboratories
ASHRAE
At a minimum the mechanical code identifies certain hazards that cannot be
connected to a manifold exhaust system and at minimum these should be
separated from the enthalpy wheel exhaust system. In addition, technical data
reports “virtually no cross-contamination (independently certified to be less than
0.04 percent)” should be provided for EHS records. This should be requested from
all potential vendors or specification should be limited to vendors meeting the
agreed upon criteria and provided to EHS for review.

24. Design Process
Critical Duty Project Design Process
•Labs are not all the same – evaluate the purpose of the facility and
establish an initial design approach
•Complete a full Risk Assessment Analysis involving the Health and
Safety officers
•Provide independent carry-over test data for use by owner and
code authorities
•Complete accurate full benefit and life cycle cost analysis,
highlighting both energy savings, chiller – boiler impact and carbon
footprint
•Provide a critical duty wheel designed specifically for laboratory
environments – limit contaminant carry-over, corrosion resistance,
antimicrobial surface, anti-stick, etc.

25. Design Process
Critical Duty Project Design Process (continued)
•Provide experienced startup to review installation, airflows,
pressures, purge settings, etc.
•Coordinate SF6 testing and commissioning report after final air
balancing but prior to occupancy
•Complete real time contaminant testing (TVOC) and
commissioning report after occupancy and use of facility to
document wheel performance
•Monitor system performance, pressures, flows and purge
performance (HSM) and alarm if problem with system
•Trend energy savings over time and highlight benefits provided
with owner and designer

26. Flexibility
Fume Hood Flexibility
Fume Hood Exhaust Capacity Assessment
Location Fume Hood Type LF of hood Hood Max Fume
exhaust length Hoods per
capacity per (ft) floor
floor
Bldg X Standard (100 CFM/LF) 320 8 40
Bldg Y Standard (100 CFM/LF) 450 8 56
Bldg X Low Flow (60 CFM/LF) 540 8 68
Bldg Y Low Flow (60 CFM/LF) 740 8 93

27. Dilution Assessment
Sample Calculation
Dilution Assessment

28. Dilution Assessment
Energy Recovery Wheel Carry-over Analysis: “Spill Scenario”

29. Dilution Assessment
Energy Recovery Wheel Carry-over Analysis: “Spill Scenario

30. Dilution Assessment
Findings:
Under this worst case spill scenario, none of the chemicals listed
would be introduced to the space at more than 6% of the threshold
limit value allowable (exposure thought to be safe to occupant - 8
hours per day, 5 days per week).
As it relates to recent interpretations by ASHRAE, it is important to
point out that ASHRAE allows more than 10 times this amount, or
100% of the TLV to be re-entrained into the fresh air intake from the
exhaust fans during a spill event (Appendix F and AIHA/ANSI
Standard Z9.5).

31. Dilution Assessment
Findings:
None of the flags shown for the 5 chemicals listed in the summary
analysis represent a health risk.
All are shown for potential odor detection under the spill scenario.
The chemicals used for this analysis came from a listing of chemicals
not detected by a monitoring system, and don't appear to be
chemicals routinely used.
Of those listed as commonly used chemicals, none were flagged. In
addition, the materials with extremely low odor detection limits
shown - i.e. mercapatans - are used in very small quantities and will
not typically be available for spill in a 500 ml quantity.

32. Dilution Assessment
Findings:
Based on the analysis there is essentially no health risk shown.
During a worst case spill scenario, there will likely be a slight odor
detected in the supply air for a very short period.
It is also likely that there would be odor detected under this spill
scenario due to the re-entrainment - even if the wheel were not to be
used.

33. Dynamic Air Monitoring

34. Dynamic Air Monitoring

35. Dynamic Air Monitoring

36. Dynamic Air Monitoring
Health and Safety Monitor Capabilities
•Limit Carry-over in VAV, variable pressure environment optimizing
health and safety
•Real time performance monitoring and trending
•Real time energy savings and accumulation
•Real time airflow measurement
•Alarm if purge pressure is lost
•Greatly reduce fan horsepower use
•Automatically determines field purge setting
•Enhances Field commissioning
•Enhances Cross-contamination testing
•Remote monitoring

37. Filtration
Effect on Particle Count
room particles/cu ft = supply air particles/cu ft + (100,000
particles/sec / airflow in cu ft/sec)
3-10 micron 1.0-3 micron .3 - 1.0 micron
MERV 14 (nominal 90-95 filter): >90% >90% 75%-85%
HEPA @ 99.97%: -- -- 99.97%

38. Filtration

39. Case Study
King Faisal Specialist Hospital
Biotechnology Research Lab
Riyadh, Saudi Arabia

40. Case Study
Climate Analysis

41. Temperature Range

42. Monthly Diurnal Averages

43. Dry Bulb x Dew Point

44. Psychrometric Chart

45. Case Study
Potable water service is
much more difficult to
supply at consistent,
cost effective levels.

46. Energy = Water
Energy Use per 1000 gallons of water delivered
12
10 Well Water
kWh per 1000 Gallons
8
Surface Water
6
Brackish Water
4
2 Sea Water
0

47. Case Study
4 ACH & 8 ACH Layout
EXHAUST
HOOD
SUPPLY AIR -
CHILLED BEAM
(TYP.)
EXHAUST
REGISTER
(TYP.)
Supply Air provided by
Chilled Beam System

48. Case Study
12 ACH Layout
EXHAUST
HOOD
SUPPLY AIR
DIFFUSER (TYP.)
EXHAUST
REGISTER
(TYP.)
Supply Air provided by all air system (In order to achieve high air
change rate, chilled beams are not used.)

49. Case Study
Four Models Compared:
• 12 Air Changes per Hour
• 8 Air Changes per Hour
• 4 Air Changes per Hour (unoccupied)
• 8 Air Changes per Hour, chilled beams rotated 90 degrees (perpendicular)

50. Case Study
Velocity Vector

51. Case Study
Particle
Tracking PARTICLE END
POINT
PARTICLE
START POINT
PARTICLE END
POINT
PARTICLE
START POINT

52. Case Study
Local Mean Air Age

53. Case Study
Room Temperature

54. Case Study
Air Change Effectiveness

55. Case Study
CO2 ppm

56. Case Study
Energy Analysis

57. Case Study

58. Case Study
Summary
A state-of-the-art system that is safe, healthy
and effective.
Optimal thermal comfort and air quality.
Controlled space pressurization based on
fume hood usage and pollutant control.
30+% energy savings.
Flexibility for future iterations of space
planning and equipment concentrations.
Optimized construction costs by reducing air
handling unit sizes, duct sizes, shaft sizes and
penthouse sizes throughout the building.

59. This concludes The American Institute of Architects
Continuing Education Systems Program
Utilizing Energy Recovery and Optimizing Air Exchange Rates in Laboratory
Buildings to Achieve Optimal Energy and Air Quality Results
John Swift, Jr., PE, LEED, CEM
jswift@cannondesign.com
Labs21 2011 Annual Conference
Providence, RI