Sign #5 - Sustainable Sites - How much money does the college save by having windows
(and needing less artificial light)?
SBVC saves thousands of dollars a year by selecting high performance windows that also contribute to lower
energy costs due to the placement of windows in key locations that minimizes the need
for using overhead lighting.
Just like in your home, selecting high performance windows (and their strategic locations
within your house) provides a variety of benefits such as:
Heating & Cooling Season Savings
Low-emittance coating, gas-fills, and insulating spacers and frames result in a lower
rate of non-solar heat loss/gain (U-factor), meaning less winter heat loss. Many low-emitting
coatings also reduce solar heat gain.
Improved Daylight & View
Beyond the obvious nature of minimizing use of overhead lighting, many low-emitting
coatings can reduce solar heat gain significantly with a minimal loss of visible light
With a low U-factor, window temperatures are more moderate. With a lower solar heat
gain coefficient (SHGC), there is less discomfort from the summer sun.
Frame, spacer and glazing materials that resist heat conduction do not become as cold
and this results in less condensation.
Coatings on glass or plastic films within the window assembly can significantly reduce
the ultraviolet (UV) and other solar radiation which causes fading of fabrics and
Lower Mechanical Equipment Costs
Using windows that reduce solar heat gain (low SHGC) may allow for smaller, less expensive
cooling equipment. Windows with a very low U-factor may ensure winter comfort even
without the need for heat registers near the windows.
(Reference: Efficient Windows Collaborative – Regents of the University of Minnesota,
Twin Cities Campus, College of Design, Center for Sustainable Building Research)