RTO Systems are gaining wide spread acceptance due to an 85% reduction in combustion fuel bills. Louis Herrington will present design details for a new type of Regenerative Thermal Oxidizer. Existing RTO type Oxidizers operate with Reverse Flow of hot gas and fresh air. The new type uses one way flow for both hot stack gas and fresh air. The advantage of the new type RTO is that full heat capacity of the Pebble Bed is maintained allowing extended switching time between Pebble Beds. With existing types the switching time is reduced about 2.5 minutes. Contaminated air can be reversed and sent out the stack unburned unless special means are added to purge the beds. Such RTO types can give satisfactory performance for some dilute solvent burners but HAPs can pose a difficult problem. The new type RTO works well with dilute air streams from suction ducts that are used to evacuate sample points, and system purges in Chemical Process Plants. Such RTO systems are also useful as retrofits for existing Thermal Oxidizers. Design details to be discussed will include Residence Time, Pebble Bed Size, Blower Selection, and the effect of pressure drop in the bed.