The Excel is the best-selling unit in North America and for good reason. It is a high capacity Bio-drum toilet that is very simple to operate, features well proven technology and is extremely reliable. The Excel was the  first ever self-contained composting toilet to be certified by the National  Sanitation Foundation (NSF). So, when you purchase an Excel, you are literally  purchasing a composting toilet that sets the standard.

The Excel has enough capacity that it can be used just about anywhere; in residences, cottages and even in light commercial applications.

To simulate residential use the Excel was tested by the National Sanitation  Foundation (NSF) at maximum capacity for 6 continuous months, during which the  Excel produced no odor and produced a clean, safe compost. Only Sun-Mar  self-contained units are listed for residential and cottage use by NSF, whose Standard #41 is the toughest composting performance standard in the world.

The 2" vent is attached at the top back of the Excel and can be  installed invisibly by running it through the wall and up the outside wall. For  comfort the Excel has a sturdy detachable footrest which can be removed to pull  out the finishing drawer.

In normal use the Excel can normally evaporate all liquids, however a ½" emergency drain is fitted at the rear and this should be connected if the unit is to be used residentially or heavily, or if prolonged power outages are expected.