Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Normally HDD and CDD are associated with a specific climate rather than to a particular building. ASHRAE 90.1 defines them as:
degree-day: the difference in temperature between the outdoor mean temperature over a twenty-four-hour period and a given base temperature.
In general, HDD and CDD are used as proxies to indicate much heating and cooling a typical building might have in different climates. It is a rough proxy since all buildings are different.
HDD is often at base 65F and CDD is at base 50F. The ASHRAE Handbook of Fundamentals (2017) contains Chapter 14 which describes this in more detail and has some example. For EnergyPlus weather files, the accompanying "stat" file contains information about HDD and CDD per month and annually.
