well i couldnt really read all this thread but unless your venting the heat directly outside you got nothing to worry about, the imaging system you guys are all worried about is called a f.l.i.r or forward looking infared. This device if focused on your house will not show an outline of your room due to the heat it cannot i repeat CANNOT see through walls or roofs trust me. when the authorities use these they are looking for an inordanent ammount of heat being vented outside especially in the winter because people really dont expell heat in the winter. if your not venting heat directly outside then relax and sleep well if your still nervous educate yourself on infared technology.

-secret