Thermal insulation involves wrapping the copper refrigerant lines in high-density foam to prevent energy loss and "sweating" inside your walls. Our Installation Kits feature UV-rated white insulation that is thicker than the industry standard. This is essential for maintaining the efficiency of a Tri-Zone system where lines may be exposed to the elements. To prevent birds or rodents from damaging this foam, always use Line Set Covers for any exterior runs. A Bravo Milano 18,000 BTU Universal Floor/Ceiling unit can lose up to 10% of its cooling power if the line sets are poorly insulated. For specialized environments, you can find extra-thick insulation in our Other Accessories catalog. Proper insulation is the easiest way to ensure you are getting every BTU you paid for.