Abstract: Systems and methods for the delivery of fluidic substances in an HVAC system are provided herein. Described herein are various examples of a prisoner cell fluidic substance delivery system. The delivery system installs on an HVAC duct servicing one or more cells. The delivery system includes a removable hatch that allows personnel to access the interior of the HVAC duct. The hatch and its access into the interior of the HVAC duct may be sized to allow for the ability of personnel to clear any debris or other foreign material from the interior prior to the insertion of a fluidic substance, such as tear gas or pepper spray. The various examples described herein allow the introduction of substances to a single cell or a limited number of cells without the need to generally disperse the substance.