aim the heater to where we want the heat.
-- we use lots of blankets on the bed, so have only left the catalytic heater on while we slept 2-3 times in the last 14 years. when we do use the heater while we sleep we slightly open a window by the bed.
-- always, while the heater is on, the ceiling vent is open, usually at least half way.
-- needing to have the vent open usually brings a response about how much heat you loose with a partially open window and ceiling vent. well, just go outside and stand by your forced air furnace while it is running. you are probably 