A system comprising: a dryer of a printing system comprising: web conditioners (310-320, 350-352) configured to condition a web of print media; intake ports configured to supply air for the web conditioners; and outlet ports configured to remove air for the web conditioners; a concentric duct system for the dryer including a central hub (550, 750) with concentric supply and return plenums that are stacked with one on top of the other, the concentric duct system for the dryer either comprising: (a) a supply hub including a tubular body with a lower portion and an upper portion, and including supply nodes around the lower portion; a return hub including a body around the upper portion of the supply hub, and including return nodes around the body; supply ducts configured to connect the supply nodes and the intake ports of the dryer; and return ducts configured to connect the return nodes and the outlet ports of the dryer; or (b) a supply hub with first air passages removably attached around a perimeter of a first hub configured to removably attach with the intake ports of the web conditioners; and a return hub with second air passages removably attached around a perimeter of a second hub configured to removably attach with the outlet ports of the web conditioners; wherein the supply hub comprises the supply plenum that includes and/or attaches with a blower and/or heating equipment, wherein the return hub comprises the return plenum that draws exhaust and used air from drying system back onto a blower and/or heating equipment of supply hub, and wherein the supply hub and the return hub are positioned concentrically with one another on a side of the dryer. a dryer of a printing system comprising: web conditioners (310-320, 350-352) configured to condition a web of print media; intake ports configured to supply air for the web conditioners; and outlet ports configured to remove air for the web conditioners; web conditioners (310-320, 350-352) configured to condition a web of print media; intake ports configured to supply air for the web conditioners; and outlet ports configured to remove air for the web conditioners; a concentric duct system for the dryer including a central hub (550, 750) with concentric supply and return plenums that are stacked with one on top of the other, the concentric duct system for the dryer either comprising: (a) a supply hub including a tubular body with a lower portion and an upper portion, and including supply nodes around the lower portion; a return hub including a body around the upper portion of the supply hub, and including return nodes around the body; supply ducts configured to connect the supply nodes and the intake ports of the dryer; and return ducts configured to connect the return nodes and the outlet ports of the dryer; or (b) a supply hub with first air passages removably attached around a perimeter of a first hub configured to removably attach with the intake ports of the web conditioners; and (a) a supply hub including a tubular body with a lower portion and an upper portion, and including supply nodes around the lower portion; a return hub including a body around the upper portion of the supply hub, and including return nodes around the body; supply ducts configured to connect the supply nodes and the intake ports of the dryer; and return ducts configured to connect the return nodes and the outlet ports of the dryer; or (b) a supply hub with first air passages removably attached around a perimeter of a first hub configured to removably attach with the intake ports of the web conditioners; and a return hub with second air passages removably attached around a perimeter of a second hub configured to removably attach with the outlet ports of the web conditioners; wherein the supply hub comprises the supply plenum that includes and/or attaches with a blower and/or heating equipment, wherein the return hub comprises the return plenum that draws exhaust and used air from drying system back onto a blower and/or heating equipment of supply hub, and wherein the supply hub and the return hub are positioned concentrically with one another on a side of the dryer.