Understanding CCAC HVAC Guidelines
The Canadian Council on Animal Care (CCAC) HVAC Guidelines establish environmental control standards for laboratory animal facilities in Canada. These guidelines are an addendum to the CCAC guidelines on laboratory animal facilities and focus on heating, ventilation, and air conditioning requirements essential for animal welfare.
Performance-Based Approach
The CCAC guidelines take a performance-based approach, meaning:
- Facilities can use various methods to achieve required environmental conditions
- Compliance is measured by actual environmental parameters, not just equipment specifications
- Continuous monitoring demonstrates that standards are being met
- Flexibility is allowed when animal welfare outcomes are achieved
Who Must Comply
These guidelines apply to:
- University research facilities
- Government laboratories
- Pharmaceutical research facilities
- Biotechnology companies
- Any institution housing animals for research under CCAC oversight
Temperature Requirements
General Standards
CCAC guidelines specify:
- Most mammals: 18-24°C recommended range
- Species-specific needs: Temperature appropriate for species being housed
- Stability: Minimal temperature fluctuations
- Monitoring: Continuous with alarm systems
Special Considerations
Different species may require different temperature ranges:
- Rodents often prefer the warmer end of the range
- Some species require specific temperature gradients
- Neonatal animals may need supplemental heating
ATEK provides configurable monitoring for each housing area, with alerts set to species-appropriate ranges.
Humidity Control
Acceptable Ranges
CCAC recommends:
- General range: 30-70% relative humidity
- Optimal: 40-60% for most species
- Stability: Avoid rapid fluctuations
Impact on Animal Welfare
Improper humidity can cause:
- Ringtail in rodents (low humidity)
- Respiratory issues (high humidity)
- Skin and coat problems
- Increased disease susceptibility
ATEK monitors humidity continuously and alerts staff when conditions deviate from acceptable ranges.
Air Quality Standards
All CCAC air quality measurements are differential - the difference between room air and supply air, not absolute readings. This is fundamental to the CCAC standard and ensures that measurements reflect contaminants generated within the room itself.
Ammonia (NH3)
CCAC guidelines specify (Guideline 4):
- Operational target: Less than 5 ppm differential above supply air
- Maximum limit: Must not exceed 25 ppm
- Measurement: Differential (room air minus supply air)
High ammonia levels indicate:
- Inadequate ventilation
- Poor sanitation practices
- Overcrowding
- Need for more frequent cage changes
Carbon Dioxide (CO2)
Guidelines specify (Guideline 5):
- Target: Less than 500 ppm above supply air (differential measurement)
- Note: 5,000 ppm is the absolute occupational exposure maximum, not the CCAC operating target for animal facilities
- Measurement: Differential (room air minus supply air)
Particulate Matter (PM2.5)
CCAC specifies quantitative limits (Guideline 6):
- Target: Less than 12.0 ug/m3 or less than 35.3M particles/m3 differential
- Measurement: Laser-based optical particle counter at 0.3 um channel
- Measurement type: Differential (room air minus supply air)
Total Volatile Organic Compounds (TVOC)
CCAC specifies TVOC limits (Guideline 7):
- Target: Less than 200 ppb / less than 500 ug/m3 above supply air
- Measurement: Photoionization detector (PID) with 10.6 eV lamp
- Measurement type: Differential (room air minus supply air)
CCAC Table 1 - Contaminant Limits
| Contaminant | Supply Air Target | Indoor Air Target (Differential) | Maximum Limit |
|---|---|---|---|
| NH3 | 0 ppm | Less than 5 ppm above supply | 25 ppm |
| CO2 | 350-600 ppm | Less than 500 ppm above supply | 5,000 ppm (occupational) |
| PM2.5 | Less than 10 ug/m3 or less than 28.2M particles/m3 | Less than 12.0 ug/m3 or less than 35.3M particles/m3 | 60 ug/m3 or 176.5M particles/m3 |
| TVOC | 0 ppb / 0 ug/m3 | Less than 200 ppb / less than 500 ug/m3 above supply | 1 ppm or 2,500 ug/m3 |
Ventilation Requirements
CCAC defines three ventilation scenarios based on monitoring capability:
Scenario 1: Demand-Based HVAC with Continuous Monitoring
- No minimum ACH required
- HVAC system adjusts ventilation in real-time based on air quality readings
- Continuous monitoring of all four contaminants (NH3, CO2, PM2.5, TVOC)
- Greatest energy savings while maintaining compliance
- Requires sensors meeting CCAC accuracy specifications
Scenario 2: Non-Demand HVAC with Periodic Monitoring
- Minimum 12 ACH required
- Fixed ventilation rate with periodic air quality checks
- Monitoring performed at regular intervals to verify conditions
- Less energy-efficient than demand-based approach
Scenario 3: No Monitoring
- Must maintain 15-20 ACH
- Highest ventilation rate to compensate for lack of monitoring
- Most energy-intensive approach
- No real-time visibility into air quality conditions
ATEK’s continuous monitoring supports Scenario 1 (demand-based HVAC), enabling the greatest energy savings while maintaining full CCAC compliance.
Sensor Specifications
CCAC specifies accuracy requirements for air quality sensors:
NH3 Sensors
- Accuracy: +/-2 ppm or 2.5%
- Resolution: 0.25 ppm
- Technology: Photoionization detector (PID) or dedicated sensor
CO2 Sensors
- Accuracy: +/-75 ppm (up to 1000 ppm)
- Resolution: 3 ppm
- Repeatability: 10 ppm
- Technology: Infrared
PM2.5 Sensors
- Accuracy: +/-25%
- Technology: Laser-based optical particle counter
- Channel: 0.3 um minimum
TVOC Sensors
- Accuracy: +/-0.2 ppm (as isobutylene) or 2.5% (whichever is greater)
- Resolution: 0.025 ppm
- Technology: PID with 10.6 eV lamp
Calibration Requirements
CCAC defines calibration schedules based on sensor deployment:
Centralized (Fixed) Sensors
- Factory calibration every 6 months
- On-site verification between calibration cycles
- Calibration records must be maintained
Separate (Portable) Sensors
- Calibrate before every measurement session
- Never use separate sensors for more than 1 month without recalibration
- Calibration must be traceable to recognized standards
Episodic Events
Unpredictable events such as dropped cages, bedding spills, or equipment failures can cause sudden and significant air quality excursions. These events highlight why continuous monitoring paired with demand-based HVAC response is the most effective strategy:
- Immediate detection: Continuous sensors detect contaminant spikes within minutes
- Automatic response: Demand-based HVAC increases ventilation automatically
- Staff notification: Real-time alerts ensure personnel can respond to the root cause
- Documentation: Event data is captured for compliance records and trend analysis
Without continuous monitoring, episodic events may go undetected, exposing animals to elevated contaminant levels for extended periods.
Air Recirculation
CCAC explicitly precludes air recirculation in animal facilities due to cross-contamination risk. Key points:
- 100% outside air must be supplied to animal housing areas
- Recirculated air can spread pathogens, allergens, and contaminants between rooms
- This requirement applies even when high-efficiency filtration is available
- Differential measurement between supply and room air can verify compliance
Monitoring Requirements
Critical Parameters
CCAC requires monitoring of:
- Temperature
- Relative humidity
- Air quality indicators (NH3, CO2, PM2.5, TVOC)
- HVAC system performance
Alarm Systems
Requirements include:
- Audible and/or visible alarms
- Alarm notification to responsible personnel
- After-hours response capability
- Documentation of alarm events
ATEK provides multi-channel alerting via SMS, email, and phone calls, ensuring responsible personnel are notified immediately when conditions deviate from acceptable ranges.
Documentation for CCAC Assessment
Required Records
Facilities must maintain:
- Environmental monitoring data
- Alarm response records
- Equipment maintenance logs
- Calibration certificates
Record Retention
CCAC specifies:
- Minimum: 1 year retention for all environmental monitoring records
- Recommended: Up to 5 years for comprehensive compliance demonstration
- Records must be readily accessible for CCAC assessment visits
Assessment Visits
During CCAC assessment visits, inspectors review:
- Environmental monitoring systems
- Historical data and trends
- Response to out-of-range conditions
- Documentation completeness
- Sensor calibration records
ATEK maintains complete environmental records with timestamps and audit trails, ready for CCAC assessment visits.
Ventilated Racks and IVCs
Rooms using individually ventilated cages (IVCs) or ventilated racks must still meet the same room-level air quality standards. Since cage supply air is drawn from the room environment, room-level monitoring remains essential. CCAC does not provide different air quality targets for ventilated rack rooms.
How ATEK Supports CCAC Compliance
Continuous Monitoring
ATEK monitors critical environmental parameters:
- Temperature readings every 15 minutes
- Humidity monitoring with configurable alerts
- Multi-contaminant air quality monitoring (NH3, CO2, PM2.5, TVOC)
- Trend analysis for proactive management
- Historical data for compliance demonstration
Immediate Alerts
When conditions deviate from acceptable ranges:
- SMS text message alerts
- Email notifications
- Phone call escalation
- Configurable alert thresholds
Assessment-Ready Documentation
ATEK provides:
- Complete temperature, humidity, and air quality logs
- Calibration certificates
- Excursion reports with corrective actions
- Exportable data for CCAC review
- Records stored for up to 5 years
Research Integrity Support
Documented environmental conditions:
- Support reproducible research outcomes
- Provide evidence for publications
- Demonstrate animal welfare compliance
- Enable retrospective analysis