Ir-cameras(detectors) for rent.

For those who can not sleep at night...You can rent IR camera(detector) from this site ...Thermography Inspection and The Infrared Camera
So you can take some pictures when lights and fans are off and temp is the same or very close to the rest of the house, and then take one when everything is on. Then take pictures of neighboring buildings to compare heat signatures...

 

I do not know for sure (most likely not, your dryer creates more heat than those lights...)
I am guessing that location of your grow area( in the house) and location of the hot air exhaust along with the amount of lights in your grow area will play a role in heat signature (size (??)).
I think if "ONE" recycle hot air in to one of the internal walls or in between basement ceiling and 1st floor opening or in between 2nd floor and 1st floor ceiling openings(instead of your attic or running directly outside ) then it would be harder to detect .Because air in surrounding rooms and insulated walls should work as shield... Again, this is just me guessing... There is also IR block film http://www.discount-hydro.com/productdisp.php?pid=552&navid=33. Also you can look for Radiant barrier Radiant Barrier Technology & Products
And for Radiant paint http://www.koolcoat.com/ witch can possibly create protection(probably the easiest method of reducing heat signature out of 3 listed above)

http://en.wikipedia.org/wiki/Infrared_photography

 

Here is the video of police using FLIR on the helicopter at night .http://wn.com/Police_Helicopter_with_FLIR
You can see that most of the heat is coming trough the ventilation pipes and windows...(probably around 75F)
And also if you look at the fresh blood that came front he suspects body , you'll see that even temperature of 36.6C/ 98 F (normal body temperature) will glow on FLIR if FLIR operator has direct shot of the heat sours. But on the other hand you can not see peoples heat signatures in surrounding buildings. Roofs and air in the attics creates IR shield and preventing FLIR to see trough it. But who knows, FLIR can be probably adjusted to the higher levels of sensitivity...

And here is another video of British police using FLIR at the day light to spot illegal 420 grows..[ame="http://www.youtube.com/watch?v=CRbBu8nkjRk&feature=player_embedded"]http://www.youtube.com/watch?v=CRbBu8nkjRk&feature=player_embedded[/ame]
And here is the brief overview of FLIR[ame="http://www.youtube.com/watch?v=sudf5xDIhmM&feature=player_embedded"]http://www.youtube.com/watch?v=sudf5xDIhmM&feature=player_embedded[/ame]