Explain the heating degree day application. What will be an ...

[bclement10]

Explain the heating degree day application.
  What will be an ideal response?

Question 2

Explain the effects humidity has on diurnal temperature ranges.
  What will be an ideal response?

[sultana.d]

Answer to Question 1

ANSWER: The heating degree day application was developed by heating engineers to estimate energy needs. It is based on the assumption that people will begin to use their furnaces when the mean daily temperature drops below 65 degrees Fahrenheit. Therefore, heating degree days are determined by subtracting the mean temperature for the day from 65 degrees Fahrenheit. Thus, if the mean temperature for a day is 64 degrees Fahrenheit, there would be 1 heating degree-day on this day. On days when the mean temperature is above 65 degrees Fahrenheit, there are no heating degree days. Hence, the lower the average daily temperature, the more heating degree days and the greater the predicted consumption of fuel. When the number of heating degree days for a whole year is calculated, the heating fuel requirements for any location can be estimated.

Answer to Question 2

ANSWER: Students should demonstrate an understanding that in humid regions the diurnal temperature range is usually small. Haze and clouds lower the maximum temperature by preventing some of the Sun's energy from reaching the surface. At night, moist air keeps the minimum temperature high by absorbing Earth's infrared radiation and radiating a portion of it to the ground. An example of a humid city with a small summer diurnal temperature range is Charleston, South Carolina, where the average July maximum temperature is 33 degrees Celsius (91 degrees Fahrenheit), the average minimum is 23 degrees Celsius (73 degrees Fahrenheit), and the diurnal range is only 10 degrees Celsius (18 degrees Fahrenheit).