When air is used as reinforced insulation, the appliance shall be constructed so that clearances cannot be reduced below the values specified in 29.1.3 due to deformation as a result of an external force applied to the enclosure.NOTE 1 A sufficiently rigid construction is considered to meet this requirement.NOTE 2 Deformation due to manhandling the appliance has to be taken into account. Compliance is checked by inspection and by manual test.