HVAC Systems and Their Role in Infection Control and

Report
Presented by:
John Martinelli
Corporate Director of Healthcare Services
Forensic Analytical Consulting Services. Inc.
November 14, 2013 – CSHE Orange County Chapter In-Service Webcast
Upon completion of this session you will be able to:
:
◦ Discuss the impact of HVAC system on infection control and
prevention in hospital settings;
◦ Describe the importance of pressure relationships established by
the HVAC systems;
◦ Explain how air exchange rates and pressure differentials work
together to control and remove airborne contaminants;
◦ List resources available to assist in determining how a room’s
HVAC system should perform based on the room use;
◦ Describe the impact of temporary or unplanned changes to the
HVAC system’s function can impact the environment; and
◦ Describe methods and tools used to confirm the system is
functioning as designed
Major Functions of HVAC
•
•
•
•
Provide fresh air
Control temperature and humidity
Filter air coming in to the building
Control air flow
– By creating pressure differentials
– Directional supply (laminar flow)
– Alignment of supply and exhaust/return
• Quickly relocate, dilute and remove
airborne contaminants
Teamwork Required
• Air Exchanges
– Calculations based on space volume and total
air supplied to the space
(20’ x 20’ x 10’ = 400 cubic foot space, with 100 CFM
supplied gets one room volume of air exchange every 4
minutes or 15 ACH)
• Pressure differentials
– Barriers required (walls and doors, ceilings and
floors)
– Open doors can defeat the design
– Amount of air supplied and air removed must
be different
Air Exchanges
What it does
• Supplies filtered, fresh air to the space
– In with the good
• Dilutes and replaces
– Out with the bad
– CO2, airborne contaminants
Presumes no new contaminant being introduced
Presumes perfect air mixing
Pressure Differential (ΔP)
• Positive pressure
– More air supplied to space than removed
• Examples
– Protective Environment (PE) Rooms
– Patients at high risk of acquiring infection
– Operating Rooms
– Wrap and Pack (Clean side) of Sterile
Processing
Pressure Differential (ΔP)
• Negative pressure
– More air removed from space than is supplied
• Examples
–
–
–
–
Airborne Infection Isolation Rooms (AIIR’s)
Restrooms
Scope Wash
Decontamination (Dirty side) of Sterile
Processing
Why Bother?
• Required by Code
–
–
–
–
ANSI/ASHRAE/ASHE Standard 170-2008 (Table 7.1)
AIA Guidelines, 2001
FGI Guidelines, 2010 – TJC (EOC Standard)
Cal Mechanical Code (Table 4A) - OSHPD
• Written Policy/Management Plans
• And It Works!
– Reduces HAI’s
– Provides defensibility
Why Bother?
• Stepped up enforcement
– Joint Commission looking at pressure differentials
more closely than ever
– OR’s, Endoscopy, SPD/CSP
– Findings can be for EOC and Leadership
But it was compliant when it was built
(So do I have to bring it up to current code?)
• Can remain as installed unless:
– Change in Room Function (per paragraph 104.3)
– Remodel (per paragraph 104.1, minor remodel
OK)
– Deemed necessary by building official for the
general safety and welfare of the occupants and
the public (per paragraph 102.6)
Per OSHPD Code Application Notice,
Can Minor Adjustment = Major Changes
• IAQ Complaints
– Staff restricting flow, changes things everywhere
• Outdoor intakes require inspection and
maintenance
• Filter replacements
– Clogged filters impact air supply
(Quantity)
• Impact of Construction Projects
– Temporary Negative Pressure Areas Impact other
Areas
++
++
How do we know it’s working?
• Test and Balance Reports
– Measure supply (and exhaust/return) volumes
from all registers in all critical spaces
– Check Pressure Differentials at all doors and
windows
– Open windows and doors?
– SPD doors open for work flow
– Roll up doors at Materials Receiving and doors
to hall propped open = ??
How do we know it’s working?
Tools to Test
• Test and Balance
• Pressure
Differentials
Micromanometer
Balometer
Rotating Vane Anemometer
:
◦ The HVAC system can have a significant positive impact on
infection control and prevention in hospital settings;
◦ In addition to making the indoor environment comfortable
air exchange rates and pressure differentials work together
to control and remove airborne contaminants;
◦ The California Mechanical Code provides tables to show how
the HVAC system should perform based on space use;
◦ Temporary or unplanned changes to the HVAC system’s
function can impact the environment; and
◦ We can use a variety of tools and specialty vendors to test
how well our permanent and temporary ventilation systems
are working.
Questions?

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