[GoFish_Tony]

I have started construction of my Pop Can Solar Heater and have a question for you all.

I will duct my cold air in through the bottom and hot air out the top.
My question is; "Should the Hot Air Plenum be larger/smaller/same size, as the Cold Air Plenum?

I admit I know nothing about HVAC or Ducting air flows.

Any help would be greatly appreciated,
Tony