This post looks more in depth into the problem of inefficient thermal insulation and how you can improve the efficiency of your tunnel oven
Industrial Hybrid Tunnel Oven
How to replace oven insulation?
Thermafiber® Fire & Sound Guard® Plus
How to replace oven insulation?
Forced Convection Tunnel Bakery Ovens
How to replace oven insulation?
Yet Another Reflow Oven
Whirlpool Range Repair - How to Replace the Insulation (Whirlpool
Owens Corning R-30 Thermafiber Fire and Sound Guard Plus Mineral