have the air on non recirc and run the heating and the aircon together if you can. That's what i used to do in the jimney (reccommended in the jimney handbook.)
Have the heater temp as hot as you can. The intention is the same as in a house...warm air to maximise its ability to hold water vapour, warm surfaces to minimise the precipitation of the vapour onto cold surfaces and good ventilation to let in dyer air and let out the moist air...and direct the air to the upper vents ie not round your legs and feet