1. Hospital Microbiome Project
Overview of building science measurements
January 15, 2013
Dr. Brent Stephens and Tiffanie Ramos, Illinois Institute of Technology
Dr. Jeffrey Siegel, University of Toronto
Dr. Brent Stephens, Ph.D.
Assistant Professor
Department of Civil, Architectural and Environmental Engineering
Illinois Institute of Technology
brent@iit.edu
Built Environment Research Group
Advancing energy, environmental, and www.built-envi.com
sustainability research within the built environment

2. Overview
• We are tasked with characterizing the hospital in mostly
non-biological ways during the yearlong study
– Outdoor air ventilation rates
– Human occupancy
– Temperature + relative humidity + light intensity
– Room pressurization
– Surface characteristics
• We will assess by measuring a variety of parameters in:
– Patient rooms (x 10)
– Mechanical rooms (x 2)
• Experimental plan development
– Initial plan by Jeffrey Siegel (University of Toronto)
– Three hospital visits by IIT
– Feedback from UC oversight committee, facilities, and engineers

3. Building science experimental plan
• We have two main priorities with our measurements:
1. Get the measurements done accurately
2. Do so in the least invasive way possible
• Our current plan will require some minor room modifications
– Purpose is to limit in-room interactions and retrieve data from hallway
– Mostly small penetrations in ducts and walls
• We are working on these
• Patient rooms
– 5 rooms on each of the 9th and 10th floors
• West wing
– 9th floor
• Rooms 09014-09018
– 10th floor
• Rooms 10014-10018

4. Patient room measurements
• Four measurement locations in each patient room
– Measuring at 5-15 minute intervals
1. HVAC return grille
• CO2
• Pressure (flow)
• Temperature and RH
• HVAC filter-based microbial sampler
2. HVAC supply diffuser
• Temperature
• Pressure (flow)
3. Near patient
• Temperature, RH, and light intensity
4. Doorway
• Beam break occupancy sensor

5. Patient room measurements
• Most sensors will be installed in the ceiling plenum
Alcove
Cabinets
HVAC Supply Diffuser Absorber column
Hallway Entry
Firewall
Beam-
HVAC break
Window
Occupancy
Return Sensors
Grille
T T/RH/CO2/Airflow
Airflow Bathroom
T/RH
Light
HVAC filter based microbial sampler

6. HVAC filter bioaerosol „sampler‟
Magnetic filter frame

7. Patient room instrument enclosures
Pressure
CO2

8. Patient rooms: Surface characterization
• Still a point of discussion
• Where bio samples are taken on surfaces
– Temperature: Point and shoot infrared thermometer
– Water activity
• Basically RH at surface
– Discussions of additional characterization of chemical compounds on
surfaces (e.g., chem wipes) and/or surface roughness (e.g,. force
microscopy)

9. Mechanical rooms
• Three measurement locations in each of 2 sets of mechanical systems
– AHU 6 (located on the 11th floor)
• Serves 10th floor
– AHU 11, 12, 13, and 14 (located on 11th and 12th floors)
• All connected to serve 8th and 9th floors
12th floor (mechanical room)
11th floor (mechanical room)
11th floor (mechanical room)
10th floor
(oncology) 10th floor (oncology)
9th floor
(patient rooms) 9th floor (patient rooms)
8th floor
(patient rooms) AHU 6 (alone)
AHU 11-14 (all connected)

10. Mechanical rooms
• Temperature, RH, and CO2 in each of:
– Outdoor air
– Return air
– Supply air (mixed OA + RA)
• Measurement of CO2 provides outdoor air ventilation rates
– Fraction of outdoor air supplied Data Logger (w/USB)
Temp.
Probe
CO2
Sensor
Data Logger (w/USB)
Temp.
Probe
Data Logger (w/USB)
CO2 Temp.
Sensor Probe
Csupply - Cout
FOA =1-
Creturn - Cout
CO2
Sensor

11. PATIENT ROOMS
Room survey

12. Return Air
Supply Air

13. Return Air

14. Return Air Grille
-Pressure Sensor (w/ power)
-CO2 Sensor (w/ power)
-Datalogger (T/RH)
-HVAC filter bio sampler

15. Supply Air

16. Supply Diffuser
-Pressure Sensor (w/ power)
-2 temperature probes
-Datalogger

17. Supply Duct

18. Alcove
(from inside
patient room)

19. Alcove
4 USB cables
2 absorber columns

20. Firewall between
patient rooms and
hallway

21. Drop ceiling space

22. Power Outlet

23. Beam-break
occupancy Sensor

24. MECHANICAL ROOMS
Room survey

25. Outside Air
Supply Air

26. Relief Air
Return Air

27. AHU

28. AHU

29. AHU

30. Current status
• Still building and calibrating equipment in laboratory at IIT
– T/RH, CO2 and pressure
– Filter media installed at hospital for validation
– Filter magnetic frame being constructed
• Meeting with construction/safety/electrical teams at hospital
– Today
– Finalizing room penetration and power plan
• Intensive setup and on-site calibration period
– By end of January
– Testing mixing assumptions, flow calibration, sensitivity testing
• Trial run
– By first of February

31. Questions/comments
brent@iit.edu

32. Required “construction” and aesthetic/code issues
• USB cables through fire wall
• USB cable output at nurse stations
• HVAC filter media installation
– Magnetic filter frame
• Loose cables in the plenum (and potentially in sight)
– Return air and supply air
• Exact location of portable HOBO logger
– Magnetic
• Occupancy sensor
– Likely magnetic
• Power requirements
– Low voltage DC, hopefully from extension cord in plenum
• CO2 absorber column just outside in the hallway plenum
• Pressure taps in return and supply ductwork

33. Longer term setup and sampling plan at the hospital
• Immediate
– HVAC filter on 1-2 sample return grilles
– Can we collect enough aerosols to detect microbial communities?
– If so, we will proceed with media and frame order
• Mid to late January
– Install an entire setup as a prototype in one patient room
– Verify our equipment plan and order additional supplies
– Test our “intensive” calibration procedures
– Also explore mechanical room installations (much less invasive)
• Late January to early February
– Replicate successful prototype in patient rooms

34. Particle removal efficiency of HVAC filter media
.

35. Patient Room Building Science Equipment Layout
Two adjacent rooms can feed one alcove, supplying:
4 USB cables for data retrieval, and
2 0.25 inch outer diameter tubes for absorber column (for CO2)
All through a 2 inch conduit through firewall (exact location TBD)
AC power strip or multi-outlet extension cord
(need 3) from outlet behind TV: 120 V Alcove
Cabinets 2” conduit through firewall
12 VDC, 1000 mA
Supply Diffuser
Hallway
Occupancy
Firewall
Sensors
Return Grille
Power
USB
From the AC power strip, 2-3 12V Bathroom
DC, 1A power supplies will connect Tubing
to our equipment. Very low power.
UL Listed. Voltage Output
Firewall
Note on voltages:
DC power to instruments (red) is 12VDC, 1A
Voltage output is for data output (purple) is maximum 0-2.5 VDC

36. Patient Rooms
Pressure Sensor
Data Logger
CO2 Sensor
(w/USB)
Pressure Sensor
+ Filter
Temp. Probe
(x2)
Data Logger (w/USB)
Data Logger (w/USB)