Heating degree-days (HDD) integrate over time which simple comparison between outdoor temperature and a balance/base temperature?
Choices
- (A) Always above base
- (B) Equals dew point
- (C) (Base − T_out) for hours when T_out < base, summed/integrated
- (D) Humidity only
Correct answer: (C)
(Base − T_out) for hours when T_out < base, summed/integrated
Explanation
HDD = Σ max(0, T_base−T)/24 per day, etc. — used for load estimation.