Annual conduction by degree days calculator

Degree days estimate conduction only, not the full building load.

Units

Q_{\text{annual}} = U \times A \times \mathrm{DD} \times 24

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

Q_{\text{annual}} = 0.1 \times 5000 \times 5000 \times 24 = 60{,}000{,}000

Symbol	Meaning	Unit
$Q_{\text{annual}}$	annual conduction heat flow	Btu/yr
$\mathrm{DD}$	annual HDD or CDD on matching base	°F·day/yr
$U$	overall heat conductance	Btu/(h·ft²·°F)
$A$	envelope surface area	ft²

Symbol	Meaning	Unit
$Q_{\text{annual}}$	annual conduction heat flow	kWh/year
$\mathrm{DD}$	annual HDD or CDD on matching base	K·day/year
$U$	overall heat conductance	W/(m²·K)
$A$	envelope surface area	m²

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.