Effect of air flow on temperature inside box

[e2m2a]

If I have a heat source on for a one hour period inside an adiabatically sealed box, such as a 10,000 watt light bulb turned on for an hour, and simultaneously I have a fan on that constantly circulates the air inside the box, would a temperature probe measure a lower temperature due to the circulating air then if the air was not circulating?

I am conducting a similar experiment and the temperature is not rising as it should. I suspect it is because of circulation of air inside the test box due to a fan.

 

[Dr Lots-o'watts]

Seems to me like the fan forces the air to make contact with the walls, which are in contact with colder exterior air. So indeed, the inside air should take longer to heat than if it weren't moving at all. Seems to make sense. Of course, getting the numbers would be important to validate any explanation.