HVAC Systems and Their Role in Infection Control and Prevention Presented by: John Martinelli Corporate Director of Healthcare Services Forensic Analytical Consulting Services. Inc. November 14, 2013 – CSHE Orange County Chapter In-Service Webcast

Presentation Objectives 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 Pressure differentials 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 perfect air mixing From the CDC Guidelines for Environmental Infection Control In Healthcare Facilities, June 2003 If reintroducing new contaminant (dust) then the calculations are not applicable but the concept of dilution/reduction still applies 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

Microenvironments

Why Bother? Required by Code Written Policy/Management Plans 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

Recommendations become Requirements

Requirements (2013 California Mechanical Code)

Requirements (2013 California Mechanical Code)

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

Impact of Temporary Changes

Impact of Temporary Changes + + + +

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 = ??

Rotating Vane Anemometer How do we know it’s working? Tools to Test Test and Balance Pressure Differentials Micromanometer Balometer Rotating Vane Anemometer

Summary : 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?