Baseline Condition & Problem Definition

Baseline Condition

Indoor environments—particularly school classrooms—operate without a standardized method to establish and document baseline environmental conditions that influence airborne pathogen transmission.

Key variables such as:

• Temperature
  
  

• Humidity
  
  

• Ventilation performance (air changes per hour)
  
  

• Filtration effectiveness
  
  

• Occupancy load
  
  

are either:

• Measured inconsistently
  
  

• Assumed based on system design
  
  

• Or not recorded at all in a continuous, verifiable manner
  
  

As a result, there is no reliable way to determine whether a space is operating within conditions that reduce or increase airborne transmission risk.

Lack of Continuous Environmental Record

Most current approaches rely on snapshot measurements or generalized assumptions about system performance.

This creates critical gaps:

• No continuous record of environmental conditions over time
  
  

• No documentation of how conditions fluctuate during occupancy
  
  

• No verification that systems maintain performance under real-world use
  
  

Without a structured environmental record, baseline conditions remain undefined.

Disconnect Between System Performance and Environmental Outcome

HVAC systems are typically evaluated based on:

• Design specifications
  
  

• Equipment capacity
  
  

• Installation assumptions
  
  

However, there is no standardized method to verify:

• Whether system output (BTU) translates into actual environmental conditions
  
  

• Whether energy input (kW) is producing effective ventilation and filtration
  
  

• Whether those conditions reduce airborne transmission risk
  
  

This creates a disconnect between system operation and actual environmental performance.

Absence of Evidence-Based Decision Thresholds

Interventions are often performed without a structured decision framework.

• Adjustments are made based on experience or assumption
  
  

• Invasive actions may occur without verified need
  
  

• Outcomes are rarely measured or validated
  
  

There is no consistent process to determine:

• When intervention is necessary
  
  

• What type of intervention is appropriate
  
  

• Whether the intervention produced measurable improvement
  
  

No Per-Occupant Accountability

In high-density environments such as classrooms, occupancy is known and consistent.

However, current systems do not account for:

• How many individuals are being served by the system
  
  

• The relationship between system output and occupant exposure
  
  

• The level of environmental protection delivered per person
  
  

This prevents evaluation of:

• Individual exposure risk
  
  

• Efficiency of environmental protection
  
  

• Resource allocation effectiveness
  
  

Resulting Problem

The absence of a defined baseline, continuous environmental record, and verified outcome framework leads to:

• Assumption-based system operation
  
  

• Inconsistent environmental conditions
  
  

• Unverified airborne transmission risk
  
  

• Limited accountability for performance
  
  

This creates a structural gap in public health protection, where interventions are implemented without measurable confirmation of effectiveness.

Problem Statement 

Indoor air management currently operates without a standardized, evidence-based framework to define baseline conditions, guide intervention decisions, and verify outcomes.

As a result, airborne pathogen risk is managed through assumption rather than measurable, documented environmental performance.