Batch Units

• Batch units are also called manual units because water has to be poured directly into them. They are convenient for home owners and come in different sizes. Countertop models only purify about one gallon at a time while floor models purify up to 10 gallons at a time.
  
  

Continuous Flow Units

• These units are also known as automatic or semi-automatic units. Continuous flow units are connected to the water line and store the pure water in a reservoir under the sink. Since they are connected to the water line, continuous flow units provide virtually endless amounts of pure water.
  
  

Certification

• According to Water Distiller USA, it is important to make sure a distiller is NSF certified. NSF Certification assures consumers that the product is safe, marketed truthfully, structurally sound and consistent in quality. There is a difference between "Tested for NSF Standards" and "NSF Certified".
  
  

Volatile Organic Compound Removal

• Distillers can remove VOC's in three ways: gas vents, fractional columns or activated carbon filters (ACF). Gas vents allow VOC's to escape during the boiling process before the water is sent to the cooling coils. Fractional columns use differential cooling to remove VOC's from the water, and ACF's absorb the VOC's as the water is filtered through.