Heating consumption of buildings

Scope

To define heating consumption of buildings.

Definition

Heating consumption (Q) of buildings can be defined with knowledge of surface area of building, inside and outside temperature in certain time period, and heat permeability factors. Easiest way to use heating consumption is to define it as floor area weighted calculation.

Assumptions:

Af = Ar
Aw = nAf
A = Af+Aw+Ar=(n+2)*Af

Buildings overall heat transfer coefficient per floor area is calculated as:

Uf = (Af/Af*Uf + Aw/Af*Uw + Ar/Af*Ur)/(Af/Af)
=[(1/n)*Uf + n*Uw + (1/n)*Ur)]/(n+2)

where A_f is area of floor, A_r is area of roof, A_w is area of walls, A is area of building, which emits heat, n is number of floors in the building and U_f is the overall heat transfer coefficient of floor, U_w the overall heat transfer coefficient of walls, and U_r is the overall heat transfer coefficient of roof. Unit of areas are m², unit of the overall heat transfer coefficients are kW/(m² K).

Heating consumptions of building is calculated as:

Q = Uf * Af * (Tin-Tout)dt

where U_f is floor weighted overall heat transfer coefficient per floor area of building, A_f is area of floor, and T_in is inside temperature and T_out outside temperature in time dt.Unit of areas are m², unit of heating permeability factors are kW/(m² K).

Unit

kW/year