Forvarmende

Forvarmende refers to the deliberate raising of temperature in a component, system, or environment before normal operation begins. The goal is to reduce thermal stress on materials, decrease lubricant viscosity, improve starting reliability, and support more efficient operation when service begins. The concept is used across engineering and industry and is commonly expressed in Norwegian as forvarming or preheating.

Applications include internal combustion engines and vehicles in cold conditions, where devices such as engine block heaters or coolant heaters warm the engine and fluids before starting. In industrial plants and power generation, preheaters for air, feedwater, or process streams raise temperatures upstream of subsequent equipment to improve energy efficiency and reduce emissions and thermal shock.

Common methods are electrical resistance heating, circulation of hot fluids or steam through heat exchangers, and targeted radiant heating. The choice of method depends on factors such as the required temperature, response time, energy availability, and safety considerations. Effective insulation and control systems help minimize energy use and prevent overheating.

Benefits include easier starting, reduced wear, improved filtration and chemical reactions, and smoother ramp-up of processes. Potential downsides are energy costs, the need for maintenance of heating equipment, and the risk of overheating or uneven heating if not properly controlled.

The term derives from for- (“before”) and varmende (“warming”).

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