For now I'm using 4 home made humidifiers out of plastic bar soap holders, 2 on top shelf and 2 on bottom. Drilled many holes in top and sides, fit florist foam inside, and charge them with 50/50 solutions of Polyglycol and Distilled water. Humidity is holding great right around 70% measured with a Wal-Mart digital meter. This is a temporary location in the spare bedroom that is kept cool so the heater does not run much.