külmik

Külmik is the Estonian word for a refrigerator, a household appliance that keeps food and drinks cold to slow spoilage. In operation, the refrigeration compartment is typically maintained at roughly 2 to 5°C, while the freezer is kept at about -18°C. Modern models often offer adjustable temperatures, special drawers, and separate temperature zones.

A refrigerator works by a vapor-compression refrigeration cycle. A refrigerant circulates through a compressor, condenser, expansion device, and evaporator. The evaporator absorbs heat from the interior, cooling the air, and the condenser releases heat to the surroundings. The cycle is powered by electricity and may use environmentally friendly refrigerants such as isobutane (R600a) or hydrofluorocarbons (R134a).

Common designs include top-freezer, bottom-freezer, side-by-side, and French-door configurations, as well as compact models for small spaces. Frost-free or self-defrosting systems prevent ice buildup in the freezer and sometimes in the refrigerator compartment.

From an energy perspective, refrigerators are rated for energy efficiency, with EU labeling and kWh/year estimates to guide consumers. Efficiency has improved due to better insulation, tighter door seals, and efficient compressors. Proper use—avoiding door left open, keeping coils clean, and ensuring vents remain unobstructed—reduces consumption. The environmental impact depends on the refrigerant choice and energy use; older CFCs were phased out in favor of more eco-friendly options, and many new models use low-GWP refrigerants.

Historically, refrigeration evolved from iceboxes to electrically powered units in the early 20th century, with widespread adoption after World War II. Today, refrigerators are essential kitchen appliances found in homes around the world, including Estonia, where energy standards and disposal rules align with EU regulations.