Layer 2: insulate the cab forehead

The hidden radiator

The upper-front steel section above the cab had little/no insulation. In direct sun it became a broad hot surfacefeeding the front zone.

Our fix

We placed reflective insulation behind the interior covering across the width. Surface temperature by touchdropped sharply and the area behaved more like the insulated living section.

Reflective is not magic R-value

A low-emissivity surface needs an adjacent air space to work primarily as a radiant barrier. Compressedbetween solids, it behaves mostly as a thin conductive layer. Use proper insulation and air-gap strategy for theactual cavity.

Safety

Do not block airbags, curtain-airbag deployment, wiring, drainage, structural access or required ventilation. Usematerials suitable for vehicle temperature and flame/smoke requirements.

System rule

Do not judge a cooling upgrade at the vent. Judge it by the hottest occupied zone, humidity, energy usedand whether the system can recover that energy safely.

CHAPTER CHECK

• I can explain which heat path this step addresses.• I measured its effect at front, middle and rear - not only by touch.• I added its power, failure mode, maintenance and safety action to the system plan.