I would like to increase the humidity of my room. The room is heated with a hot water radiator pipe: hot water flows through the pipe that runs along the walls. I cannot control the temperature of the water (the pipe feels warm, but not hot at all) and can only control the volume of water that runs through the pipe (I have a scale from 1-10). The pipe is 1.5 inches wide. Humidity is low in the winter.

How can I increase the humidity of my room given these conditions?