Garage Foundation Wall Mold

[VHConstruction]

Just looking for your input here.
Insulated garage heated with radiant tube heater. It has been a real cold winter here and now the foundation wall is sweating causing surface mold to grow. Does this have anything to do with the radiant heater used to heat the garage or is it just because the winter has been so cold the exterior walls and ceiling are insulated but the exposed 8" of foundation wall makes for a cold zone causing moisture?
Anyone else ever have this issue?

Any input would be greatly appreciated.

Thanks

 

[MagKarl]

Does your heater exhaust inside or outside?

 

[VHConstruction]

Radiant tube heater exhausts outside

 

[Jlbc212]

To get condensation on the foundation walls the surface temp of the walls has to be at or below the dew point temp of the air in the garage and there has to be moisture in the form of water vapor in the garage. I suspect the foundation walls have been cold right through the winter, so that hasn't changed. Somehow there's now an increase of water vapor in the air inside the garage. That can happen as outside temps increase. The warmer the air is, the more water vapor it is able to hold.