Perhaps this has been tried, perhaps common knowledge, but it seems to me that using ductwork to draw intake air from outside for a dust collector would not only reduce the heat lost in winter but also improve dust collection.
I'm referring here to a wood lathe.
Couldn't you affix the ductwork under the bed, between the ways, and creating a bit of an up draft that would move directly into the DC's hood.
Less chance of whatever flows through it to absorb heat.
Also, maybe help keep the shop just a bit cooler in hot wearther.