There are circumstances in which a cellar design may require a larger unit due to some existing design restrictions. There are several factors such as glass, stone, concrete, etc. which will seem adequate but do not offer the insulation capacity required to maintain the optimum environment. We recommend purchasing a unit with a larger capacity to compensate for the design limitations. Under sized cooling units can lead to pre-mature failure and/or prevent the system from reaching the desired set temperature. As a result they are not covered under warranty.