Why ASHRAE 55 & 62.1 Matter in HVAC Comfort Evaluation

In Vietnam, HVAC design is required to comply with national standards such as ASHRAE, QCVN, and TCVN.

However, current Vietnamese standards still have limitations when evaluating:

• Thermal comfort within the occupied zone

• Ventilation effectiveness

• Fresh air distribution in real spaces

This is where ASHRAE standards play an important role in advanced HVAC design.

Key ASHRAE Standards

ASHRAE Standard 55

Defines thermal comfort conditions based on:

• Air temperature

• Relative humidity

• Air velocity

• PMV / PPD comfort indices

ASHRAE Standard 62.1

Provides guidelines for:

• Ventilation effectiveness

• Fresh air supply rates

• Indoor Air Quality (IAQ)

These standards are widely used as technical references for high-performance buildings and international projects.

CFD + ASHRAE = Real Performance Evaluation

When Computational Fluid Dynamics (CFD) is combined with ASHRAE standards:

✔ Thermal comfort is evaluated inside the occupied zone, not just using average room values
✔ Air distribution and ventilation effectiveness become visually measurable
✔ Design risks can be identified before construction

This integrated approach is becoming a key trend in modern HVAC design and building performance analysis.