Copper pipes which are widely used in the refrigerator industry can sometimes work in high humidity atmospheres and in aggressive conditions which can produce dangerous corrosion phenomena of the pipes. Moreover, the design of the refrigerator cooling circuit can introduce some other corrosion problems because copper pipes are frequently in electrical contact with aluminium pipes causing serious galvanic attack on the less noble metal. In order to eliminate these corrosion phenomena, the insulation of capillary copper tubes, used for the production of regenerative heat exchanger, was proposed, by the application of organic coatings. The protection of copper capillary tubes was obtained using the same technology (coextrusion) and the same resins (polyvinylformal or polyestherimide layer followed by a polyamideimide layer) employed for insulating copper wires for electrical motors. The barrier properties and adhesion of the selected organic coatings have been studied using coated copper samples in the as received conditions or after pipe bending or coating scratching, in order to simulate actual defects which can be introduced during refrigerator assembly. EIS proved to be a very useful technique in order to evaluate the protection properties of the selected coatings. PVF coatings showed good barrier properties only when 60 mu m thickness coating was applied. Nevertheless, when artificial defects were produced in the coating, barrier properties were remarkably diminished. In fact, mechanical deformation increased water permeability and coating delamination easily occurred at scratches. PE coatings showed better barrier properties, even applying a thinner coating (40 mu m). Mechanical deformation, in the range of 10% elongation, was sustained by this coating without suffering a clear decrease of its barrier properties. Moreover, this kind of coating showed better resistance to coating delamination processes, probably because of better adhesion to the metal substrate. Such property could be greatly enhanced for both kind of coatings using a suitable surface pretreatment.