How is sating on room air spelled Is it sating or satting?

The correct spelling is “sating.” However, if you’re referring to a medical context, where it might relate to a patient “sating on room air,” it typically refers to a person’s oxygen saturation levels, and the correct spelling would be “saturating” (e.g., “saturating on room air”).

In short, the correct form in this context would be saturating.