Given a low temperature of 18°F and a high of 42°F, with an indoor temperature of 65°F, calculate the Heating Degree Days (HDD).

To determine the Heating Degree Days (HDD) using the provided temperatures, the formula is typically:

HDD = (Base Temperature - Average Outside Temperature)

The base temperature is conventionally set at 65°F for heating needs. First, you need to calculate the average outside temperature based on the given low and high temperatures.

The average outside temperature is calculated as follows:

Average Temperature = (Low + High) / 2

Average Temperature = (18°F + 42°F) / 2

Average Temperature = 60°F

Next, using the base temperature of 65°F, we can now calculate the HDD:

HDD = Base Temperature - Average Outside Temperature

HDD = 65°F - 60°F

HDD = 5 HDD

This value indicates that there is a need to heat the building in order to maintain the desired indoor temperature. Given the understanding of how HDD is calculated and the proper use of the average outside temperature, it appears there was an oversight in initially identifying the correct option. The calculated value suggests a need for clarification in the provided choices or question details. The conclusion here reflects a fundamental look at degree days for heating, emphasizing that the actual heating requirement based on provided temperatures would yield a minimal HDD