I definitely wouldn't recommend anything smaller... Winter is finally upon us here in Pittsburgh, PA and I have been running this humidifier on high 24/7 in just a small 8' x 11' room. As we speak, the current humidity outside is 55% and this big humidifier is struggling to keep the humidity in my snake room at only 43%! I definitely have to be getting a new pump for the built in humidifier system on my furnace, because this humidifier isn't keeping up by itself...
Thanks. I was debating on whether to get this or something smaller just for the one level. The furnace is on the same level where the snakes are so I'm sure that's not helping.