Prescriptions for Critical Healthcare Cx. John D. Villani, P.E. Associate Grumman/Butkus Associates

Transcription

1 Prescriptions for Critical Healthcare Cx John D. Villani, P.E. Associate Grumman/Butkus Associates

2 AIA Quality Assurance 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 Retrocommissioning

3 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

4 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)

5 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

6 Medical Industry Developments Common thread to airborne pathogens? HVAC Systems Filtration Pressurization Air changes Cooling coils Drain Pans Ventilation Exhaust

7 Medical Industry Developments Common thread to waterborne pathogens? Domestic Water Systems Cold Water Hot Water Hot Water Recirculation

8 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

9 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

10 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

11 Current Construction Process Controls System can be the key Control System Design System Diagram with Sequence of Operations Points List Specification Monitoring Alarming? Trending??

12 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

13 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)

14 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

15 Case Study Air Handlers Air Handler Equipment Details

16 Case Study Air Handlers Air Handler Equipment Details

17 Case Study Operating Rooms Operating Room (OR) Design Details 15 Operating Rooms Temperature Range Deg F Relative Humidity Range % RH Occupied Mode 30 Air Changes per Hour Unoccupied Mode 15 Air Changes per Hour Supply VAV Return Modulating Damper Static Pressure Room Control

18 Case Study Operating Rooms Operating Room (OR) Design Details

19 Case Study Humidification Humidification Issues Humidification controlled based on measured return air RH vs. setpoint via reset schedule Frequent high humidity alarms

20 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

21 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 = ( ) % OR s Room Relative Humidity Average = 47.0% RH

22 Case Study Humidification Operating Conditions

23 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

24 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

25 Case Study OR Pressurization Operating Conditions

26 Case Study OR Pressurization

27 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

28 Case Study Occupancy Sensors Operating Conditions

29 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??

30 Case Study Economizer Cycle

31 Case Study Economizer Cycle

32 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

33 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

34 Case Study - IFB steam preheat coil Resulting Effects from operating conditions 23.1 Degree Heat Gain from Preheat and humidifier

35 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

36 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

37 Case Study - IFB steam preheat coil Implemented Changes

38 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

39 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

40 Simultaneous Humidification and Cooling Operating Conditions

41 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

42 Simultaneous Humidification and Cooling Implemented Changes Air handler humidification was deactivated at 50 degrees wet bulb Missed criteria as per the specifications

43 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

44 Construction Issues Case Study - Summary 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)

45 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

46 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

47 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

48 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.

49 Thank-you John D. Villani, P.E., LEED AP, C.E.M., QCxP Grumman/Butkus Associates (847)