Prescriptions for Critical Healthcare Cx · Prescriptions for Critical Healthcare Cx. Learning...
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John D. Villani, P.E. Associate Grumman/Butkus Associates Prescriptions for Critical Healthcare Cx
Transcript of Prescriptions for Critical Healthcare Cx · Prescriptions for Critical Healthcare Cx. Learning...
John D. Villani, P.E.AssociateGrumman/Butkus
Associates
Prescriptions for Critical Healthcare Cx
Learning Objectives
1. Medical Industry Changes and how they impact Design, Construction, Operations and Commissioning
2. Review the current construction process and how Cx can enhance the process
3. Review the Case Study of a hospital surgical pavilion addition, and the design and operational issues and results of Retro- commissioning
AIA Quality Assurance
Medical Industry Developments
October 2009, Medicare will cease paying for several “reasonably preventable”
hospital mistakes•
Eight preventable mistakes approved for 2009
•
More mistakes targeted for 2010 and beyond•
Other insurance carriers watching and speculated to follow Medicare’s lead
Medical Industry Developments
Medicare’s list for 2009•
Urinary tract infections from catheters
•
Bloodstream infections from catheters•
Falls
•
Bed Sores, or pressure ulcers•
Objects left in patient during surgery
•
Blood incompatibility•
An infection after heart surgery
•
Air embolism (air bubble in a blood vessel)
Medical Industry Developments
What possible “reasonably preventable” hospital mistakes that might have funding
eliminated in the future?•
Airborne, waterborne, blood borne pathogens?
•
Airborne –
Tuberculosis, Aspergillosis, Staphylococcus
•
Waterborne –
Legionella
Medical Industry Developments
Common thread to airborne pathogens? •
HVAC Systems ○Filtration○Pressurization○Air changes○Cooling coils○Drain Pans○Ventilation○Exhaust
Medical Industry Developments
Common thread to waterborne pathogens? •
Domestic Water Systems ○Cold Water○Hot Water ○Hot Water Recirculation
Medical Industry Developments
Impact to current projects •
Infectious Control Department documents infection rates in hospitals
•
Case Study Project –
Had increase in infection rates
•
HVAC system was identified due to uncontrolled temperature and humidity swings
•
All supply air ductwork was cleaned and sterilized
Presenter
Presentation Notes
Costs – 1,200/s
Current Construction Process
Design –
Bid –
Build, who controls the quality for MEP systems?
•
HVAC and Plumbing Systems○Design Team○Contractors○Testing, Adjusting and Balancing Contractor○Local Authority Having Jurisdiction○State Health Inspectors○Operations Staff
Current Construction Process
What happens after the occupancy?•
New team of staff take over operations and maintenance
•
Poor transfer of knowledge of proper system operation, nuisances, backup modes
•
System deviations “Tweaking”•
Loss of critical system parameters
•
Controls system –
fire fighting
Current Construction Process
Controls System can be the key•
Control System Design○System Diagram with Sequence of Operations○Points List○Specification○Monitoring○Alarming?○Trending??
Adding Cx to the Current Construction Process
Controls System can be the key•
Commissioning the Control System○FPT Testing○Alarming○Trending○Persistence○Operator Training
OR Pressure
Case Study – Hospital Retro-Commissioning
New surgical Pavilion Project Details•
56,000 Sq.Ft
New Construction Space
•
45,000 Sq.Ft. Renovation of Existing Hospital•
$35M Construction costs
•
3 New Air Handlers, ORs
and Central Sterile•
15 New Operating Rooms (ORs)
Case Study – Air Handlers
Air Handler Design Details•
ORs
served by two air handlers
•
50,000 CFM each•
Back up through cross over dampers
•
50,000 CFM design during backup mode•
25,000 -
30,000 CFM during normal mode
•
Oversized design to handle backup mode
Case Study – Air Handlers
Air Handler Equipment Details
Case Study – Air Handlers
Air Handler Equipment Details
Case Study – Operating Rooms
Operating Room (OR) Design Details•
15 Operating Rooms
•
Temperature Range 60 –
78 Deg F•
Relative Humidity Range 40 –
60 % RH
•
Occupied Mode –
30 Air Changes per Hour•
Unoccupied Mode –
15 Air Changes per Hour
•
Supply VAV•
Return Modulating Damper
•
Static Pressure Room Control
Case Study – Operating Rooms
Operating Room (OR) Design Details
Case Study – Humidification
Humidification Issues•
Humidification controlled based on measured return air RH vs. setpoint
via reset schedule
•
Frequent high humidity alarms
Case Study – Humidification
Operating Conditions•
AHU-2 Conditions on 11/7/08 at 18:02○Discharge Air Temperature = 53.6F○Discharge Air Relative Humidity = 81.8% RH○Humidifier Valve Position = 100% Open○AHU Common Return Air Temperature = 70.7F○AHU Common Return Air Relative Humidity =
45.7% RH ○AHU Common Return Air Relative Humidity
Setpoint
= 58% RH
Case Study – Humidification
Operating Conditions•
AHU-2 Conditions on 11/7/08 at 18:02○OR’s Discharge Air Temperature Range = 59.1F –
70.0F○OR’s Room Temperature Setpoint
Range = 60.0F
–
75.1F○OR’s Room Relative Humidity Range = (41.1 -
51.6) %○OR’s Room Relative Humidity Average = 47.0%
RH
Case Study – HumidificationOperating Conditions
Case Study – Humidification
Implemented Changes•
Utilize booster humidifiers first followed by unit humidifier
•
Poll individual ORs to maintain lowest OR to 40% RH
•
High humidity takes precedence to low humidity
Case Study – OR Pressurization
Operating Conditions•
ORs were found going negatively pressurized during transition from occupied to unoccupied
•
30 ACH to 15 ACH•
Supply VAV box can decrease from occupied to unoccupied CFM in approx. 60 seconds
•
Return damper controlled by room pressure sensor takes 15 to 20 minutes to regain stable pressure control
Case Study – OR Pressurization
Operating Conditions
Case Study – OR Pressurization
Case Study – Occupancy Sensors
Operating Conditions•
OR minimum ON time –
30 minutes
•
Found the occupancy sensors with 30 minute on time windows occurring 4 to 5 times per day
•
At 15 minutes of negative pressure per occupancy change over, that is 1 hour per day the ORs are negative
Case Study – Occupancy Sensors
Operating Conditions
OR Pressurization & Occupancy Sensors
Implemented Changes•
Slow down of OR supply VAV box to decrease from occupied to unoccupied mode over a 20 minute period
•
Note behind return dampers in lieu of VAV boxes –
VALUE ENGINEERING??
Case Study –Economizer Cycle
Case Study –Economizer Cycle
Case Study - IFB steam preheat coil
AHU Design Details•
Air handlers equipped with Integral Face and Bypass (IFB) vertical steam preheat coils
•
Coils sized for 50,000 CFM at -15 Deg F and a 57 degree rise
Case Study - IFB steam preheat coil
Observed Operating Conditions○Outside air temperature = 30.8F○Mixed air temperature = 30.2F○OA dampers min and max were 100% open○Return air dampers closed○Preheat steam valve was 100% open○ IFB dampers were 0% open (fully closed around
the vertical steam coil)○Humidifier valve 40% open○Cooling coil –
inactive, no cooling
○Cooling coil discharge air temperature = 53.3F
Case Study - IFB steam preheat coil
Resulting Effects from operating conditions•
23.1 Degree Heat Gain from Preheat and humidifier
Case Study - IFB steam preheat coil
Why is this happening?•
Chilled water active above 45 degrees OA
•
Glycol active above 40 degrees OA•
IFB sequence:○Above 40 Deg OA, IFB damper open to coil and
steam valve modulates○Below 40 Deg OA, steam valve goes 100% open,
IFB damper modulates○Why –
typical design for 100% outside air, backup
mode, not normal mode○Cost of Existing Operation Est. $35,000/year
Case Study - IFB steam preheat coil
Implemented Changes•
IFB damper control is based on Mixed Air instead of Outside Air (warranty issue)
•
Steam valve modulates open instead of going 100% open
•
IFB damper modulates open after steam valve is 100% open
Case Study - IFB steam preheat coil
Implemented Changes
Case Study – Humidification Issues
Operating Conditions•
Carry Over Problem thru○Chilled Water Coil○Glycol Coil○Supply Fan○Reheat Coil○Up to and/or through final filters (HEPA)
•
Valve Modulation from 0 to 100% open•
Tripping off in high humidity safety switch
•
Sized for 100% Outside Air
Case Study – Humidification Issues
Findings and Implemented Changes•
Found bad discharge air humidity sensor
•
Tripping on High humidity safety switch •
Valve opening too fast, and too much for recirculation (normal) mode of operations
•
Limited valve to 60% during normal mode•
No limit in valve travel in emergency mode
Simultaneous Humidification and Cooling
Operating Conditions
Simultaneous Humidification and Cooling
Operating Conditions•
Found conditions○Outside air temperature = 63.7F○Outside air relative humidity = 56.1% RH○Outside air enthalpy = 22.9 Btu/Lb○Return air enthalpy = 25.2 Btu/Lb (Since the
return air enthalpy is greater than the outside air enthalpy the unit is economizer mode)
○Humidifier Valve Position = 92% open○Chilled Water Coil Valve Position = 36.7% open
•
Flooding and excessive condensate after cooling coil, even beyond drain pan
Simultaneous Humidification and Cooling
Implemented Changes•
Air handler humidification was deactivated at 50 degrees wet bulb
•
Missed criteria as per the specifications
Case Study - Summary
Design Issues•
Oversized AHU’s for backup mode
•
100% outside air design for smoke purge•
Control sequences did not address normal mode of operation at reduced operating capacities
•
No VAV boxes on the ORs return air •
OR pressurization
•
Occupancy Sensors
Case Study - Summary
Construction Issues•
No trending setup to track or monitor systems
•
Poor communication between controls contractor and engineer regarding normal vs. backup mode
•
Controls interpretation of sequences•
Very poor owner turnover, no ownership of systems or controls
•
Outside Air Flow Station (Min vs. Max)•
Fire/Smoke Dampers (NFPA 90A)
Case Study – Summary & Results
Retro Commissioning Issues•
No documented sequences of operation
•
Trending established•
Extensive effort to re-write new sequences
•
Resolved issue of IFB preheat coil and manufacture’s warranty
•
Corrected OR negative pressurization•
Improved operations staff ownership of systems and controls through training
Case Study – Results
Retro Commissioning Results•
RCx Costs y $125,000, includes○Retro-Cx Engineering○General Contractor○Mechanical Contractor○TAB Contractor○Controls Contractor (New Controllers)
•
$35,000 in savings from IFB coil changes•
3 –
4 year payback
•
Average cost/ week in the hospital y $75,000
Case Study – Real World
Retro Commissioning Hospitals•
Hospitals 24/7 Operation
•
Interruptions due to cases•
Impact to communicable pathogens and the spread of infections
•
Support the elimination of reasonably preventable hospital mistakes
AIA Quality Assurance
Portland Energy Conservation, Inc 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.
Thank-you
John D. Villani, P.E., LEED AP, C.E.M., QCxP Grumman/Butkus Associates
(847) 328-3555
