We installed overhead radiant heat in our screen print production area, mostly to minimize dust blowing around from those overhead shop blowers. It was a concrete and brick structure from the 40's. It was a good idea production wise but I'm not at all sure about the economics. The rest of the shop, including the printer area is all forced air.
My concern about radiant with the printers would be the proximity of the printers to the actual heat source. Radiant does what it is supposed to, that is, heat stuff not air. If you have a high ceiling and your units are not directly underneath the tube(s), I can't see an issue but if there 8' apart or so I wouldn't do it.