Installed in mid level bedrooms at beach house.  We opted for smaller sized model to minimize impact on room.  Even with king beds and nicely sized rooms the fan moves enough air to keep air circulating while sleeping.  THese fans will not create a wind but there is a gentile breeze...just the thing for a pleasant evening in the OBX.  Material is PVC or some kind of plastic, also a good choice for hot humid environments.   We are thinking of installing several more on covered front porch for those warm days when the breeze is not coming from the correct direction.