Vinotemp WM-4500HZD Self-Contained Wine Cellar Cooling System, Black This unit is a self-contained, all-in-one, and ready for use. No copper tubing or drain line are required. Horizontal cold air supply is optimized for use in wine rooms. When installed into a wine cabinet or cellar, this unit must vent outside. The WM-4500HZD cooling unit is designed and used to provide a stable temperature between 50~65 F for a properly insulated and sized space. The ambient temperature range for WM-4500HZD should not be higher than 95F or lower than 50F in order to operate properly. The refrigerated space will maintain humidity within the range of 50~75% RH. We use an exclusive method to provide additional humidity. Uses R134a refrigerant which is considered environmentally friendly Digital display with easy push-button controls Display notifications provide alerts help to protect your wine cellar and alert you when maintenance is required. Control panel includes digital display, manual defrost button, up and down arrows to adjust temperature as well as browse parameters, power button, and SET button.