Communicating Proof of Performance in Ventilation Systems and Set Baseline Standards for Subsequent PERIODIC ASSESSMENT
The concept of Proof of Performance (PoP) is fundamental to the success of any ventilation system installation meeting its design objectives. It ensures that the system achieves its intended purpose, complies with applicable guidelines, and adheres to regulatory requirements. By clearly defining PoP parameters and rigorously validating system performance, stakeholders can ensure optimal functionality, protect worker health, and minimize environmental impacts.
Why Proof of Performance Matters
1. Assurance of Design Intent:
PoP verifies that the system operates as per the system design point, delivering the specified air flow rate derived from LEV, GV or any specific objectives, for effective contaminant removal or process byproduct venting. Any ventilation system is designed based on it system flow rate. System flow rate are derived from the specific application of the flow rate equation either using :
typical LEV system equation such as Q-flow rate =V-volume. A-area, X-capture distance, P-perimeter, L-height from source, v-capture velocity; Q=VA, Q=V(10X^2+A), Q=1.4PLV
typical GV system equation such as flow rate Q = (ACH x Room Volume)/60
exhaust or supply based on pressurisation required such as flow rate Q = dominating Q x (percentage of pressure variance)
dilution effective ventilation flow rate such as Q’- effective ventilation = G-Generation Rate / C-Steady State Concentration
dilution actual ventilation flow rate equation for airborne hazard such as Q -f low rate = (G-Generation Rate X K-Air Mixing Factor)/C-Steady State Concentration
dilution actual ventilation flow rate equation for flammable vapour such as flow rate Q= (G-Generation Rate X K-Air Mixing Factor)/LEL -Lower Explosion Limit
Qs - volumetric flow rate for sensible heat, Qs = H-sensible heat gain / (1.08 x Delta T)
QL-volumetric flow rate for latent heat, QL= m-moisture /density x Delta rate of moisture release.
and many other customised equation subjective to the actual objective of the ventilation system
2. Regulatory Compliance:
Compliance with codes and standards, such as OSHA’s Permissible Exposure Limits (PELs), USECHH Regulation 17, 18 and 19, Clean Air Regulation 5,7,9 EPA emission standards, or industry-specific guidelines, ensures both worker safety and environmental protection. In actual fact most of this regulation spells out the proper implementation of engineering basis and practises in the design sequence, installations, commissioning and after sales. A change of management will need to addresses any changes on these documents.
3. Alignment with Industry Standards:
Recommendations from resources like ACGIH® (e.g., control velocities or hood capture efficiencies) and ASHRAE provide benchmarks for system performance. Adhering to these standards validates the system’s capability to meet occupational hygiene needs. This is important to ensure we clearly understand ventilation systems are designed precisely to meet is intended purposes without causing energy waste.
4. Risk Mitigation:
A poorly commissioned system can lead to non-compliance, increased operational costs, or failure to protect workers and the environment. PoP ensures proactive identification and resolution of such risks. In fact POP eliminates the culture of having GUESTIMATEDLY DESIGNED SYSTEM which will give the highest air flow by actually dropping the efficiencies of system and components but running a fan at a very high amp unnecessarily. A clear objective of meeting permissible exposure limit or airborne chemical concentration must be set as the objective to meet. The air flow rate must only serve as an indicative parameters and not become the primary goal to be achieved.
Key Components of Proof of Performance
1. Design Basis Verification:
Validate performance against specific design parameters, such as:
• Air volume flow rates (e.g., “x” acfm) to generate to reduce the concentration of emission to the lowest intended concentration. (ALARA, Action Level, Permissible Exposure Limit, In house standards and etc).
• Minimum duct velocities, filtration velocity, scrubbing velocity, cyclone inlet velocity, efflux velocity, etc (e.g., “y” fpm).
• Capture velocities at hoods, referenced to ranges (e.g., 150–250 fpm as per ACGIH® guidelines).
2. Pre-Installation Baseline Data:
Establish baseline conditions before commissioning:
• Measure background concentrations of dust, VOCs, or other airborne contaminants at critical locations within the facility. This is call identification of Hazard (anticipate and recognise, evaluate and control as per Industrial Hygiene tenets).
• Identify pre-existing conditions that might influence system performance (non standard air, etc)
3. Post-Commissioning Validation:
Conduct measurements after system installation and commissioning:
• Compare pre- and post-commissioning contaminant levels.
• Validate capture, transport, and emission levels against guarantees.
• Factor in ambient conditions that the system cannot control, such as plant-wide dust contributions.
4. Compliance Testing:
Verify adherence to regulatory limits for emissions and workplace exposures, ensuring:
• PELs are met or exceeded, Efflux velocity, establishment of performance monitoring criterion.
• Emission rates comply with environmental standards, load to air cleaning device is within range of design, and etc.
Challenges in Proof of Performance
1. Defining Performance Metrics:
The wide ranges in design standards (e.g., ACGIH® hood velocities) may require a focus on specific values within these ranges, based on the facility’s operational needs. A proper design steps must be taken and a proper engineering service provider must be chosen. Do not take fabricator and equipment suppliers who claims to be specialist of ventilations system who most of the time uses the well known GUESTIMATION APPROACH.
2. External Influences:
Background ambient conditions, such as dust from other processes, may mask the system’s effectiveness.
3. Control Factor Limitations:
Systems may only control certain parameters, such as point-source emissions, without addressing broader facility-wide air quality. This is why the design approach on deriving the system flow rate is very crucial in taking into consideration such as non standard air, room pressurisation, chimney emission away from plant air intake, the need to integrate sensible heat and latent heat flow rate with any LEV and GV systems, covering adhoc services air ventilation needs such as adequate ventilation during tank cleaning or silo purging and etc.
Recommendations for Effective Proof of Performance
1. Comprehensive Commissioning Plan:
Incorporate PoP as a key stage in system commissioning. The plan should include:
• Documentation of design criteria and assumptions.
• Pre- and post-installation measurement protocols.
• A corrective action framework for non-conformance.
2. Stakeholder Collaboration:
Engage project teams, including designers, installers, and environmental health and safety (EHS) personnel, to ensure shared responsibility for PoP outcomes.
3. Clear Documentation and Reporting:
Maintain detailed records of:
• Baseline measurements.
• System installation and commissioning details.
• Final PoP validation results.
4. Operational and Maintenance (O&M) Integration:
Use the O&M manual as a living document that outlines ongoing performance verification protocols and troubleshooting guidelines. Stop reactive maintenance and establish effective performance monitoring requirement in line with regulations such as USECHH Reg 17 1 a Monthly inspection, Regulation 9 of Clean Air Regulation 2014 and etc.
Proof of Performance is more than a regulatory formality—it is an operational necessity. Proper commissioning based on clearly defined PoP parameters safeguards worker health, protects the environment, and ensures the ventilation system performs as intended. By anchoring PoP in design verification, baseline evaluation, and compliance testing, stakeholders can achieve and sustain a high-performing ventilation system.