You need to contact your local DriSteem or Nortec distributor for assistance with selecting the proper model and unit. It all depends on how much moisture you need to add to your space and this will be determined by the size and configuration of the space, the tightness of the building, the nature of the artifacts you are protecting, and the set points you are attempting to maintain. A conservator can work with your facilities manager to address these issues. If you only need a small amount of humidity in one room, a stand-alone cool- mist humidifier using distilled water may be sufficient. However, such units do not deliver much humidity int0 the air. If you need more than several liters a day, you will probably need to have a steam humidifier installed. The model will depend on the amount of steam you need to produce for the space during the driest days of the year.