It's entirely possible the wires would get hot enough to get useful heat, but I think the much more practical challenge is moving the air and insulating it from

It's entirely possible the wires would get hot enough to get useful heat, but I think the much more practical challenge is moving the air and insulating it from the outside. Beyond that, you're likely also decreasing the maximal electrical current the wires can carry, as they won't be able to dissipate the heat as effectively with the additionally insulation.