I've been using a 4.5 gallon Lasko 1128 Evaporative Recirculating Humidifier for a few months now. It's rated for 3200 square feet, but it definitely wouldn't keep the humidity very high in that much space. My snake room is only about 8' x 11' and it will keep the humidity between 50% and 60% during the winter running it in high 24/7...