This AC/heated enclosure allows alarm control panels to be protected from extreme temperatures or other areas requiring UL Type 4 protection. The extra large, super tough, heavy-duty metal enclosure guards against vandalism, either accidental or intentional, as well as dirt, dust and grime. Its size allows the enclosure to house significantly sized electronic devices with space to spare. This UL Type 4 enclosure mounts to the wall enabling the units to be protected in their designated location. Unlike competitive models, this enclosure is available with a clear window allowing the unit within to be quickly identified. Both the enclosure and AC/heater unit have a durable finish to help protect against corrosion. The enclosure has two turn latches to help prevent unauthorized entry. HOW THEY WORK To help maintain the correct range of operating temperatures, the AC/heater unit cycles as required and a fan runs continuously to sustain a uniform temperature inside the enclosure. The steel AC/heater is cost effective, low maintenance, is externally mounted to minimize space intrusion and has a low ambient operation package to help prevent it from freezing. This package allows the unit to work in cold temperatures without causing the heater lines to freeze.