Well this is a patio heater i made the other day it has a fire box at the bottom then pipes up to a SS manifold it has a trio of fans to blow the hot air from the tubes and at the back has a fan that blows air up the chimney to halp draw the fire hotter
This is one I made for my brothers wedding anniversary
used a 30kg gas cylinder for the body and a small one for his head drilled a lot of holes in the top of his head to let the smoke out then added a few facial features
used a few off cuts of scaffold tube for his arms and legs