The corn heat is so cheap, I went and bought another corn burner from Facebook Marketplace and refurbished it and it's now in the shop and I'll be idling my propane fired in floor pex heat this winter. Heating a 10" thick concrete slab, 40 x 40 is quite expensive even with 6" of pink foam insulation underneath and on the sides, in the rat wall. I like a warm floor to work on but I don't like the propane bill, it's currently at $2.39 a gallon here and will probably go up appreciably over the cold months.