Understanding Discomfort
DOWNDRAFT DISCOMFORT
Cold convective air currents, formed by warm room air hitting the cold window surface, create discomfort at the occupant’s feet and ankles. The strength of these currents depends on the height of the window pane, as well as the interior temperature of the glass.
To minimize downdraft discomfort, try:
- decreasing the window height
- decreasing the window U-Value
- using a glazing assembly without a room-side low-e coating
RADIANT DISCOMFORT
Cold interior glass surfaces affect the mean radiant temperature of occupants, and in turn make them feel cold. This discomfort depends on how much the occupant “sees” of the glass, how cold the interior glass surface is and the emissivity of the glass. If the glass has a room-side low-e coating the radiant discomfort will be greatly reduced.
To minimize radiant discomfort, try:
- decreasing the total amount of glazing
- decreasing the window U-Value
- increasing the sill height
- using a glazing assembly with a room-side low-e coating
Understanding Winter Comfort