Lämpömitoitetta

Lämpömitoitetta is a Finnish term used in building services engineering to describe the process and result of sizing the heating demand for a building or an energy system. It refers to the design heating load needed to maintain specified indoor temperatures under design conditions and is used to dimension heating equipment and distribution systems.

In practice, heating load calculations are used when designing new buildings, planning renovations, or assessing district heating connections and energy retrofits. Calculations are based on factors such as climate data, building envelope properties (insulation, windows, air leakage), ventilation rates, internal heat gains from occupants and equipment, and prescribed indoor temperature setpoints. Methods can range from simpler steady‑state approaches to more detailed dynamic or hourly simulations.

The output of a heating load calculation is typically given as design heating power (in kilowatts) and, for annual planning, the expected annual heat energy consumption (kilowatt-hours per year). This information guides the selection and sizing of boilers, heat pumps, radiators or underfloor heating, and distribution networks, and it supports energy performance assessments and compliance with building regulations.

Accuracy depends on quality data and the chosen calculation method. Overestimating the load can lead to oversized equipment and higher initial and operating costs, while underestimating it may cause insufficient heating and comfort issues. Lämpömitoitetta is a foundational element in efficient, climate-appropriate heating design.