HEATING, VENTILATION AND AIR-CONDITIONING SYSTEM (HVAC) Class 1 Facility: General Anesthesia Heating, ventilation and air-conditioning system standards are a primary infection prevention and control strategy whereby contaminants are diluted and expelled through the high-frequency replacement of standing room air with clean filtered air. The Canadian Standards Association (CSA) Special requirements for heating, ventilation and airconditioning (HVAC) systems in health care facilities (CAN/CSA Z317.2-10) standard is not based on the type of room but on the functions that are expected to occur within the room. Where several functions apply in a given area of a facility, the more stringent requirements take precedence. Both health-care facility classification and area classification, as per CSA, determine the design requirements. The information contained in this document provides a general overview of the requirements. CAN/CSA Z317.2 Special requirements for heating, ventilation and air-conditioning (HVAC) systems in health care facilities shall be referenced in addition to this document. CAN/CSA Z317.2 represents the detailed requirements for HVAC in non-hospital medical/surgical facilities. ABBREVIATIONS AIA American Institute of Architects CSA Canadian Standards Association DOP Dispersed oil particulate HEPA High-efficiency particulate air HVAC Heating, ventilation and air-conditioning MDR Medical device reprocessing MERV Minimum efficiency reporting value PAR Post-anesthetic recovery PD Pressure differential RH Relative humidity T Temperature NHMSFP College of Physicians and Surgeons of British Columbia Page 1 of 8
DEFINITIONS CSA health-care facility classifications Class A-2 health-care facility A health-care facility in which patients are accommodated on the basis of medical need provided with continuing medical care and provided with supporting diagnostic and therapeutic services that can extend beyond 12 hours, and does not meet the other requirements of a Class A-1 health-care facility. Examples include: outpatient surgical services cosmetic surgical offices dental surgical offices laser eye clinics other office surgical facilities Class C health-care facility A health-care facility in which ambulatory patients are accommodated on the basis of medical need provided with supportive, diagnostic, non-invasive interventions and treatment services and stay for no more than 12 hours, and remain capable of self-preservation. Examples include: laser eye clinics cosmetic surgical offices CSA area classifications Type I A patient care area where the invasiveness of procedures, the level of risk of morbidity and mortality to patients and the level of risk of adverse outcomes to care providers necessitate more stringent HVAC and environmental requirements. Examples include: minor surgical procedures endoscopy cystoscopy dental minor procedures room operating rooms recovery rooms NHMSFP College of Physicians and Surgeons of British Columbia Page 2 of 8
Type II A patient care area of an area that is intended for the provision of services that provide direct support to patient care areas. Examples include: decontamination/soiled room preparation and packaging/clean room sterilizer room scope reprocessing room sterile storage NHMSFP Facility Classifications Class 1 Provides general anesthesia and major regional anesthesia (epidural, spinal nerve blocks) and may include use of IV sedation and/or analgesia, or local anesthesia only. Class 2 Provides use of IV sedation and/or analgesia where the patient remains responsive and breathes without assistance. Class 3 Provides local anesthesia only. May provide oral sedation but not IV sedation/analgesia or inhalants. New facilities, additions to existing facilities and/or replacement or addition of HVAC equipment in existing facilities are in compliance with CAN/CSA Z317.2-10 INDICATORS: HVAC system functions in accordance with design criteria HVAC system monitoring parameters are in accordance with design criteria Parallel air-handling units are present in CSA Class A-2 facilities for any areas that accommodate the following critical functions including but not limited to: surgery, operating rooms surgery, sterile core post-anesthetic care or recovery storage of sterile materials and supplies The position and type of supply and exhaust registers promote the movement of air within the rooms or spaces from clean to less clean areas Airflow is directed from supply to breathing zone to exhaust outlets 1, 2 All filters are clean and sealed Air supply is from: non-aspirating ceiling outlets near the center of the work area 1, 2 NHMSFP College of Physicians and Surgeons of British Columbia Page 3 of 8
ceiling outlets 3 Each operating/procedure room or area where anesthesia might be exhaled (PAR) has a minimum of two return air inlets 1, 2 Return air inlets are placed: whereby the bottom of the return air inlet is 75 500 mm above the floor 1 whereby the bottom of the return air inlet is at least 75 mm above the floor 2 near the floor 3 Rooms with inhalation anesthesia and/or inhalation analgesia have a scavenging system in compliance with ISO Z7396-2 1, 2 or CAN/CSA Z168.8 3 Minimum levels of HVAC are maintained for type I areas when the space is not occupied: Minimum of six air exchanges per hour of recirculated air 1, 2 Pressure differential across separations is maintained (7.5 Pa) 1, 2 Temperature is maintained 1 Relative humidity is maintained 1 HVAC heating plant, cooling plant and controls are connected to the essential electrical system 1. CAN/CSA Z317.2-10 2. CAN/CSA Z317.2-01 3. CAN/CSA Z317.2-M91 Existing facilities are in compliance with the CAN/CSA Z317.2 at time of build INDICATORS: HVAC system functions in accordance with design criteria* 2010 present Z317.2-10 2001 2009 Z317.2-01 1991 2000 Z317.2 M91 Before 1991 American Institute of Architects *Facilities not in compliance with CAN/CSA Z317.2 standards from time of build may be required to upgrade their existing system to be in compliance with current CSA Standards. HVAC system monitoring parameters are in accordance with design criteria The position and type of supply and exhaust registers promote the movement of air within the rooms or spaces from clean to less clean areas Airflow is directed from supply to breathing zone to exhaust outlets 1, 2 All filters are clean and sealed Air supply is from: non-aspirating ceiling outlets near the center of the work area 1, 2 NHMSFP College of Physicians and Surgeons of British Columbia Page 4 of 8
ceiling outlets 3 Each operating/procedure room or area where anesthesia might be exhaled (PAR) has a minimum of two return air inlets 1, 2 Return air inlets are placed: whereby the bottom of the return air inlet is 75 500 mm above the floor 1 whereby the bottom of the return air inlet is at least 75 mm above the floor 2 near the floor 3 Rooms with inhalation anesthesia and/or inhalation analgesia have a scavenging system in compliance with ISO Z7396-2 1, 2 or CAN/CSA Z168.8 3 Minimum levels of HVAC are maintained for type I areas when the space is not occupied minimum of six air exchanges per hour of recirculated air 1, 2 pressure differential across separations is maintained (7.5 Pa) 1, 2 temperature is maintained 1 relative humidity is maintained 1, 2 HVAC heating plant, cooling plant and controls are connected to the essential electrical system 1. CAN/CSA Z317.2-10 2. CAN/CSA Z317.2-01 3. CAN/CSA Z317.2-M91 The HVAC system is maintained in accordance with CAN/CSA Z317.2-10 INDICATORS: Filters and seals are visually inspected monthly to verify the presence of the filter and seal and to ensure proper physical condition Primary filters with a MERV rating less than 9 are replaced every 12 months or when loaded (based upon measurements of pressure drop across the filter bank) Primary filters with a MERV rating greater than or equal to 9 are replaced every 24 months or when loaded (based upon measurements of pressure drop across the filter bank) Secondary filters are replaced every 24 months or when loaded (based upon measurements of pressure drop across the filter bank) HEPA filters are replaced every 36 months or when loaded (based upon measurements of pressure drop across the filter bank) whichever occurs first Fan coils, drain pans and induction and finned units are inspected and cleaned at minimum semi-annually (usually spring and fall) Ducts are inspected at minimum annually Supply ducts are cleaned when deemed necessary by annual inspection NHMSFP College of Physicians and Surgeons of British Columbia Page 5 of 8
Return ducts are cleaned every 10 years or when deemed necessary by annual inspection, whichever occurs first Exhaust ducts are cleaned every 10 years or when deemed necessary by annual inspection, whichever occurs first Diffusers (supply, return or exhaust) are cleaned every six months HVAC Design Criteria The information contained in this document provides a general overview of the requirements. CAN/CSA Z317.2 Special requirements for heating, ventilation and air-conditioning (HVAC) systems in health care facilities shall be referenced in addition to this document. CAN/CSA Z317.2 represents the detailed requirements for HVAC in non-hospital medical/surgical facilities. Minimum filter efficiency Operating room Filter # 1 MERV 1 8 Filter # 1 50% 3 Filter # 1 30% Filter # 2 MERV 14 Filter # 2 90% Filter # 2 95% Procedure room Filter # 1 MERV 8 Filter # 1 50% Filter # 1 30% Filter # 2 MERV 14 Filter # 2 90% Filter # 2 95% Specialized operating Filter # 1 MERV 8 Filter # 1 50% Filter # 1 30% room* Filter # 2 MERV 14 Filter # 2 99.97% 4 Filter # 2 95% Endoscopy / bronchoscopy *Specialized operating room, e.g. transplants, orthopedics 1. Minimum efficiency reporting value (MERV) 2. High-efficiency particulate air (HEPA) 3. Dust spot efficiency 4. Dispersed oil particulate (DOP) Filter # 3 HEPA 2 Filter # 3 N/A Filter # 3 N/A Filter # 1 MERV 8 Filter # 1 50% Filter # 1 30% Filter # 2 MERV 14 Filter # 2 90% Filter # 2 95% Minimum outdoor air changes/total air changes per hour Operating room 6/20 6/20 6/20 Procedure room 5/15 6/20 6/20 Recovery room 6/20 6/20 6/20 Endoscopy / bronchoscopy 5/(15/20) 6/20 6/20 Dirty room (MDR) 2/10 2/8 3/12 Clean room (MDR) 3/10 3/10 3/12 Sterile storage 0/4 0/4 3/12 NHMSFP College of Physicians and Surgeons of British Columbia Page 6 of 8
Relative pressurization Operating room Positive Positive Positive Procedure room Positive Positive Positive Recovery room Positive Positive Positive Endoscopy / bronchoscopy Negative Positive/Negative Positive/Negative Clean room (MDR) Positive Positive Positive Sterile storage Positive Positive Positive Dirty room (MDR) Negative Negative Negative Pressure-critical spaces: minimum pressure differential Operating room + 7.5 Pa + 0.762 mm + Procedure room + 7.5 Pa + 0.762 mm + Recovery room + 7.5 Pa + 0.762 mm + Endoscopy / bronchoscopy - 7.5 Pa + 0.762 /- 0.762 mm + / - Clean room (MDR) + 7.5 Pa + 0.762 mm + Sterile storage + 7.5 Pa + 0.762 mm + Dirty room (MDR) - 7.5 Pa - 0.762 mm - 7.5 Pa = 0.03wc = 0.762 mm of water pressure Temperature Operating room 18 23 o C 17 27 o C 20 26 o C Procedure room 18 22 o C 17 27 o C 20 26 o C Recovery room 22 24 o C 24 o C 22 24 o C Endoscopy / bronchoscopy 18 22 o C 20 24 o C 20 26 o C Clean room (MDR) 18 23 o C 20 23 o C 22 26 o C Sterile storage 20 23 o C 20 23 o C 22 26 o C Dirty room (MDR) 18 20 o C 18 20 o C 22 26 o C Relative humidity Operating room 40 60% 45 55% 50 60% Procedure room 30 60% 45 55% 50 60% Recovery room 30 60% 50 60% 50 60% Endoscopy / bronchoscopy 30 60% 30 60% 50 60% Clean room (MDR) 30 60%* 30 60% 40 50% Sterile storage 30 60%* 30 60% 40 50% Dirty room (MDR) 30 60%* 30 60% 40 50% *As per the Ministry of Health Best Practice Guidelines for Cleaning, Disinfection and Sterilization of Critical and Semi-Critical Medical Devices relative humidity of 40 50% is preferred NHMSFP College of Physicians and Surgeons of British Columbia Page 7 of 8
Parameter monitoring: monitored, alarmed central readout Pressure differential (PD) Temperature (T) Relative humidity (RH) Parameter monitoring: local readout OR/procedure room PD, T, RH T, RH T, RH Dirty room T, RH T, RH - Clean room T, RH T, RH - Sterile supply T, RH T, RH - Parameter monitoring: calibration OR/procedure room (PD, T, RH) Monthly - - Dirty room (T, RH) Annually - - Clean room (T, RH) Annually - - Sterile supply (T, RH) Annually - - REFERENCES Canadian Standards Association. Special requirements for heating, ventilation, and air conditioning (HVAC) systems in health care facilities. Mississauga, ON: Canadian Standards Association; 2010. 70 p. CSA Standard No.: Z317.2-10. NHMSFP College of Physicians and Surgeons of British Columbia Page 8 of 8