How is a thermal comfort CFD project carried out?

An effective CFD analysis is not simply about running a simulation. It requires a clear workflow closely aligned with HVAC design objectives:

1. Define the evaluation objectives

Clearly identify the purpose of the simulation:

• Assess thermal comfort
• Evaluate ventilation effectiveness / air distribution

2. Build a CFD model that reflects reality

• Geometry of the space, furniture, heat sources
• HVAC systems (diffusers, AHU, FCU, etc.)
• Appropriate level of detail depending on the analysis objectives

3. Set boundary conditions and reasonable assumptions

• Airflow rate, supply air temperature
• Heat loads (occupants, equipment, lighting)
• Environmental conditions (outdoor climate, building envelope)

4. Analyze results within the occupied zone

Focus on areas where people actually stay:

• Air velocity
• Temperature
• Comfort indices (PMV, PPD if applicable)

5. Compare with standards (ASHRAE, ISO, etc.)

• Benchmark results against ASHRAE 55 or equivalent standards
• Determine whether comfort criteria are met

Important note

CFD should not be treated as a standalone step, but as part of an integrated HVAC design approach:

• Supports validation of design options
• Helps optimize diffuser placement, airflow rates, and air distribution strategies
• Should be combined with load calculations, equipment selection, and practical experience

👉 In other words: CFD is a decision-making tool, not the final goal.