Understanding Heating Load Results - Summary

You have completed your heating load calculation according to DIN EN 12831 – but what do all the numbers actually mean? This article explains all results in detail: from the room overview to the annual heat demand to specific renovation suggestions.

Room Heating Load vs. Building Heating Load

An important difference that is often misunderstood:

Heating Load Type	Calculation	Use
Room heating load	Transmission + 100% ventilation	Sizing radiators per room
Building heating load	Transmission + 50% ventilation	Sizing the heat generator

Why the difference? For the building heating load, only 50% of the ventilation heat loss is applied because in practice not all rooms are ventilated simultaneously.

Annual Heat Demand

In addition to the design heating load (for the coldest day), the calculator also determines the annual heat demand – how much energy you actually need over the year. This enables:

• Calculation of annual heating costs
• Heat pump planning and COP estimation
• Before/after comparison for renovations

---