Douglas, TKCamry and Nash posts both show the technical backup confirming your assumption is wrong. The point I was trying to explain was why your little experiment was flawed thus leading you to make the wrong assumption.

Two climate control systems, one inside and the other at the tailpipe.

2007 Camry Hybrid (in service June 2006)
FE: 6.77L/100km (34.8 mpg) over 37750km (23450mi)
75% city - Ave trip 20 min - 2 Winters