Passage III
Heating degree-days (HDD) and cooling degree-days (CDD) are used to estimate the amount of energy needed to heat or cool, respectively, any building on a given day. HDD are calculated by subtracting the daily mean temperature (Td) from a base temperature of 65°F. Each degree difference is one HDD. CDD are calculated by subtracting 65°F from Td.
Table 1 lists, for each of 10 US cities, the latitude of the city and the city's total HDD and CDD for a 1 yr period.
For the state of Illinois, the annual total HDD and the annual total CDD were determined for each of the years 1985-2010 (see Figure 1).
15. According to Figure 1, did the maximum HDD occur during the same year as the minimum CDD?
Your Answer is
Correct Answer is D
Explanation
Find the highest point of the HDD line and the lowest point of the CDD line according to the image, and find that the highest point of HDD is at 1996, and the lowest point of CDD is at 1992.