Guardian DP21 NEMA 12, 3R & 4Air-Cooled Panel-Mounted Air Conditioners

The Guardian DP21 is a NEMA 12, 3R & 4 rated panel-mounted air conditioner designed to maintain precise temperature control and protect sensitive electrical components in industrial enclosures. Built with a heavy-duty steel shell featuring a baked powder finish in ANSI 61 gray (with custom color options available), the unit provides robust construction that withstands demanding operational environments. All models are fully gasketed for tight, leakproof installation, ensuring compliance with NEMA Type 4 enclosure ratings for dependable environmental protection.

The Guardian DP21 incorporates advanced cooling and environmental management features that enhance both performance and operational reliability. A closed-loop cooling system isolates the enclosure interior airflow from ambient conditions, preventing humid or contaminated outside air from invading the sensitive component compartment. The built-in condensate evaporator eliminates the need for manual condensate drainage under normal operating conditions, though an overflow drain fitting and hose are included for high-humidity applications. The cooling system utilizes CFC-free R134a refrigerant and features epoxy-coated condenser and evaporator coils that withstand 1000 hours of salt spray testing per ASTM B 117, extending service life in moderately corrosive environments. A multi-layer corrugated aluminum filter with a one-piece aluminum frame removes contaminants and maintains internal cleanliness, with replacement filters readily available online.

The control and protection systems are equally comprehensive, featuring a programmable thermostat for precise temperature management and a programmable temperature alarm that alerts operators when early corrective action is needed. A compressor short cycle protector prevents damage from frequent restarts caused by low heat loads, power interruptions, or solar gain, thereby extending compressor life and reducing operational stress. The condenser blower controller optimizes cooling efficiency, while a six-foot 3-wire power cord facilitates standard electrical connections. The Guardian DP21 is UL/CUL Listed and CE Compliant, with all specifications meeting international standards for safety and performance.