My humidity is 72% right now and we have four fans circulating the warm air from the RMH (rocket mass heater). We also have two Vick's brand warm mist humidifiers that we run when it is too cold to mist the plants with the hose.
Air movement is critical but I will be mounting the fans higher up this summer (for the winter), because some orchids do not like the air hitting directly on the plant. It can stunt the blooming and cause keikis instead.
