Looking to heat.

• "Probably the easiest and most cost-efficient way to go is including a radiant heat system in the floors of rooms with tall ceilings. Because the floor is heated rather than the air, the effect is warmer for the people in the room." -- Cathedral Ceilings: Heating & Cooling Efficiently
• "Since radiant heat doesn’t heat the air directly, there’s no hot air rising (and no cold down drafts) in the room, and thus the warmth is evenly distributed throughout the space." -- Cathedral Ceilings and Radiant Heat
• "Three main types of heating are used in the uk: Upgrading to radiant floor heating will keep any size space cozy and comfortable." -- How To Heat A Large Room With High Ceilings
• "Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation." -- https://www.energy.gov/energysaver/radiant-heating