DIN EN 12831 Heating Load Dashboard

Multi-room · multi-floor design heat load (SI units)

DIN EN 12831-1

Design θe (°C)

Annual mean θm,e (°C)

Airtightness n50 (1/h)

ΔU thermal bridge (W/m²K)

Reheat f_RH (W/m²)

Total Heat Load Φ_HL

0.64 kW

637 W

Transmission Φ_T

0.36 kW

57%

Ventilation Φ_V

0.27 kW

43%

Reheat Φ_RH

0.00 kW

32 W/m² avg

Building

Room use

θint (°C)

Floor area (m²)

Height (m)

Ventilation

n_min (1/h) [0.5]

Mech. supply (m³/h)

Heat recovery η (0-1)

Building elements

Type	Boundary	Orient.	A (m²)	U (W/m²K)

Library:

Library:
		—
Library:

Living room — Φ_HL

637 W

32 W/m² · 20 m² · θint 20°C

Transmission Φ_T365 W

Ventilation Φ_V272 W

Element losses

wall (N) · f=1.00127 W

window (S) · f=1.00110 W

floor (N) · f=0.50128 W

Air: 25 m³/hinf 9 · min 25

Orientation

2 external elements

Method — DIN EN 12831-1 (design heat load)

Φ_HL = Φ_T + Φ_V + Φ_RH. Transmission Φ_T = Σ (U+ΔU_TB)·A·f·(θ_int−θ_e) with temperature-adjustment factor f per boundary (external f=1, ground f=1.45·(θ_int−θ_m,e)/(θ_int−θ_e), unheated and adjacent-room by temperature ratio). Ventilation Φ_V = 0.34·V̇·(θ_int−θ_e), V̇ = max(2·V·n50·e·ε, n_min·V). Heating design ignores solar gains; orientation drives wind-shielding and documentation.