Winter Quiz Contest [Ended]

Beinecke Plaza, devoid of snow.  

Snow is ubiquitous in New Haven, at the moment. In defiance of this, the plaza at Hewitt Quadrangle has no snow on it at all.

If you can answer correctly why that is, by tweeting to @nhvorg with #nhvsnow and the correct answer, we will award you with a giftcard to Willloughby's Coffee And Tea, who have graciously sponsored this Winter Quiz Contest. Expect more contests to be announced.

This is not an easy question. It's not an obvious answer but there is a very specific reason, and it's unlike any other for granite courtyards.

Previous Answers:

1.  It's not because of the climate control in the library (the library is of course climate controlled, but it does not affect the temperature across the entire courtyard).
2.  It's not because of office space underneath (which is true, there are offices underneath, but that's not why all the snow melts).

The correct answer via CTGirlAboutTown:
"Radiant Heating."

You Win!