Chest Freezer

Overview

A chest freezer stores frozen food in a top-opening insulated box rather than an upright cabinet. The horizontal layout is what makes it efficient: cold air is denser than warm air, so it pools at the bottom of the Cabinet and stays there when the lid is opened, instead of spilling out the way it does from a front door. That lets the compressor run less often and holds temperature longer during a power cut.

The body is a deep-drawn Inner Aluminum Liner wrapped inside a painted Outer Steel Shell, with the gap filled by injected Polyurethane Foam Insulation. The evaporator tubing is bonded directly to the outside of the liner, so the entire inner wall becomes the cooling surface. A foam-filled Lid closes against a magnetic gasket and is held up by counterbalanced hinges that take the weight of the lid at any angle.

This is a manual-defrost design. There is no fan and no defrost heater inside the box, so frost slowly builds on the walls and is cleared by hand a few times a year, draining out through the Defrost Drain at the base.

How it works

Cooling runs on a sealed vapor-compression cycle inside the Refrigeration System system, charged with R600a hydrocarbon refrigerant. The Hermetic Compressor draws in low-pressure refrigerant vapor and compresses it, raising its pressure and temperature. That hot gas flows through the condenser coil mounted against the back of the cabinet, where it gives up heat to the room and condenses into a liquid.

The liquid is then forced through the Capillary Tube, a long narrow bore that meters the flow and drops the pressure. On the low-pressure side the refrigerant enters the evaporator tubing wrapped around the liner, where it boils and absorbs heat from inside the box. Boiling at low pressure pulls the liner wall down to freezing temperatures; the vapor then returns to the compressor and the loop repeats.

A thermostat in the Thermostat & Control Board assembly senses the box temperature and switches the compressor on and off through a relay to hold the setpoint chosen on the temperature knob. The compressor itself starts under load with help from a start relay and overload protector, and its motor windings are sealed inside the welded steel housing along with the pump.

A small interior light and sliding wire baskets in the Interior complete the unit, with leveling feet keeping the cabinet steady on uneven floors.