Met with Bill to discuss his mini split system replacement. Took pictures to document the existing equipment. Bill would like to upgrade to a system that can produce heat up to 15 degrees below zero. I explained to Bill that the interior heads would have to be replaced as well, as the exterior condenser. All units have to match for proper operation. Called the supply house to get information and I was referred to the in house specialist for a consultation in order to properly recommend which unit would work best.