The simplest and fastest way to cool the garage area in your metal building is to add radiant barrier to the metal roll up garage door using the BlueTex™ Roll Up Garage Door Kits. For your convenience and easy installation, we have 3 pre-made kit sizes:
A Single Roll Up Garage Door Insulation Kit (covers up to a 12' x 12' size door): bluetexinsulation.com/products/bluetex-50-wide-roll-up-garage-door-kit
A Double Roll Up Garage Door Insulation Kit (covers two 10' x 10' doors or a single larger door up to 200 sq ft): bluetexinsulation.com/products/bluetex-50-wide-roll-up-garage-door-kit?variant=44080581050586
An Oversize Roll Up Garage Door Insulation Kit (covers up to 300 sq ft): bluetexinsulation.com/products/bluetex-50-wide-roll-up-garage-door-kit?variant=44608816218330