Calculate the kW output and BTU rating your heat pump needs based on room dimensions, insulation quality, climate zone, and window area.
Typical: 10–20%. Large glazing = +heat loss.
This is an estimate. For precise sizing, consult a licensed HVAC technician who can assess orientation, ductwork, and local codes.
Multiply the floor area (in square meters) by a watt-per-square-meter factor that reflects your insulation quality and climate. Typical values range from 60 W/m² for well-insulated modern homes in warm climates up to 150 W/m² for poorly insulated rooms in cold climates. Then divide by 1000 to convert watts to kilowatts (kW). For example, a 20 m² well-insulated room in a temperate climate typically needs around 1.6 kW.
A 25 m² bedroom usually requires a heat pump between 2.0 kW and 3.5 kW depending on insulation, ceiling height, window area, and local climate. With good insulation and a temperate climate, a 2.5 kW unit is typically sufficient. Poor insulation, high ceilings, or a cold climate can push the requirement toward 3.5 kW or higher.
Yes, insulation is one of the most important factors. A well-insulated room can lose up to 60% less heat than a poorly insulated one, meaning you can choose a significantly smaller, cheaper, and more efficient heat pump. Upgrading insulation before buying a heat pump often pays for itself through reduced equipment cost and lower energy bills.