Thermal Comfort - Creating Comfortable Environments with HVLS Fans

Ashrae Standard 55 categorises all the standard factors that affect thermal comfort and how adjusting each affects perceived comfort in indoor environments. These 6 factors are:

1. Clothes - This factor provides thermal resistances.

2. Activity level we do (Metabolic Rate). More intense the activity, the more heat we generate and dump out in the surrounding air.

3. Presence of breeze (Air Speed) - Through natural breezes or fans. Because breeze is moving the air, it drives convection cooling to transfer heat from person to surrounding air and cool the occupant down.

4. Air Temperature / Ambient Temperature - Heat flows naturally from high to low temperature. If hot, we dump heat and if cold, we gain heat.

5. Humidity - The presence of how much water vapour is in the air can determine cooling potential of space. The lower the water vapor, the greater the evaporative cooling potential.

6. Radiant Temperature (ie the sun) creates a massive thermal load through its light rays.

Some of these elements are out of our control in a working environment, but Air speed, air temperature, lowering of Humidity can work together to improve thermal comfort levels for a comfortable working environment.