If your insulation is too good, it might get too warm in the box. If the aluminized bubble wrap is not too good as a Faraday Cage you could use one of the remote sensors that come with the home weather stations. If it doesn't show up on the weather station you may have to remove some of the bubble wrap. The aluminum can stop the radio waves.

Faraday Cage:

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