I couldn't place my box fan at the top of the stairs as there was no outlet nearby and I feared tripping on the cord. So I placed the fan downstairs at the base of the stairs blowing towards the stove (which is in my downstairs family room). It really helps. Last evening I had my thermostat upstairs set on 66 and it consistently said it was 68. I think that is pretty good as my stairs take a turn at a landing downstairs, you turn, go down 2 more steps and go down a short hallway into my family room. (My fan is in the middle of that hallway aimed out into the family room.) There is no way that the insert is going to put me in the 70's upstairs, but it keeps the furnace from kicking in so often.