Human Comfort and Indoor Air Quality
Radiant systems provide control over surface temperatures within the occupied space (Mean Radiant Temperature).
Human comfort perception is mainly determined by the “Operative Temperature” which is a perceived combined effect of “Air Temperature” and “Mean Radiant Temperature”.
Radiant systems provide control over surface temperatures within the occupied space (Mean Radiant Temperature). 100% outside ventilation air is tempered to desired room temperature.
This combination provides optimum thermal comfort conditions. Traditional all-air HVAC systems perform combined space temperature and ventilation function by moving large volumes of air and control only air temperature (thermostat).
Displacement ventilation provides increased ventilation effectiveness by supplying a small amount of 100% outdoor air at low level (occupant level) and low velocity. Air is never re-circulated. Ventilation air is driven upwards by buoyancy.
This provides superior indoor air quality compared to traditional overhead HVAC and UFAD systems.
Projects using this technology require in-depth building modeling to optimize both passive architectural features and the building system design. This company uses the TAS software package to model these buildings and their systems.
Credits: Graphic Courtesy of Arizona State University