Well in my bedroom i have very limited control. I can turn heat on or off. the handle does not really regulate it. In NYC they say the window is the thermostat. It averages to 25 C but can go down to 15 or up to 32 C [close to the radiator - where i put a shelf sitting on some bricks on top of it and I keep my Adeniums / cactuses etc].
In the winter I have to water often. It gets dry too.
Well past few days it has been mild I keep the heat off and the window open all the time.
I think being native of Burma/ Indonesia 15 C may be too cold for the Ludisia to be active.
Probably you need 25 to 30 C and humidity.
I would keep it close to a light to keep it warmer and use some clear pot upside down on top of the pot to keep humidity high.
I have seen them in terrariums.
low light outdoors sometimes can mean bright light indoors...
Ludisia discolor - Wikipedia, the free encyclopedia
Now