I'm trying to model the energy savings due to improved glazing for an
apartment building. The windows will be changed from single untinted, to
triple pane low-e glass. In addition to better thermal charistics from
improved U-value and SHGC, I am trying capture the savings due to the
fact that the occupants will not have to crank up the thermostat to
raise the air temperature to compensate for the radiant cooling due to
single pane glass if you are standing near the floor to ceiling windows
in winter.
I made a guess that the average occupant will put the heating set point
at 68 instead of 70 since the improved glazing will block the radiant
cooling effect. Is there a more elegant way to model this?
Jacob Goodman , LEED AP
You might ask the question: "how much could they realistically crank it
up?"
It's not uncommon in our design work to provide thermostat controls in
spaces which really only allow the occupants to adjust the setpoint a
few degrees in either direction. There's a placebo effect of sorts when
you crank the dial/lever all the way from "red" to "blue," but given
free reign to vary the setpoint wherever, you might find cases like my
high school math teacher who was convinced she was part-penguin and all
the students had to bring jackets to concentrate in her class.
Point being, if you have to guess at a change in occupant behavior,
start with establishing to what degree they can change the setpoint.
NICK CATON, E.I.T.