1. Residential Heating and Cooling Prepared by: Will George Ryan Lester

2. Causality Parameters Temperature – variance in temperature creates different energy demands for heating and cooling. Degree day data was compiled on a state by state basis. Households - number of households was available for each state by decade and interpolation was performed to find the missing years.

3. Causality Parameter Trends Weather is assumed to remain constant over the years, but varies spatially. Housing units have been steadily increasing:

4. Heating Data Natural gas consumption per state per month is available for the past 17 years. Heating fuel usage was extracted and applied to the housing units and degree days to come up with a conversion factor in the form of Btu/Housing Unit/Degree day. Housing Units and Weather are the parameters affecting the heating and cooling requirements

5. Subtract the amount from the lowest month from each month to find the amount used for heating. (The quantity from the lowest month represents utility gas uses other than heating.)

7. Heating fuels used per household were available per decade per state (1940- 2000). These were interpolated to estimate per year for each state. Knowing the contribution in Btu by natural gas allowed the other fuel energies to be calculated. Heating Fuels

8. Heating Trend Natural Gas usage is rising, Coal and Fuel Oil usage is dropping, and electricity is rising slowly. Wood usage has dropped significantly since the 1940s.

9. Emissions Factors (Mg carbon/BBtu) Natural gas 14.47 Wood 100.67 Kerosene 19.72 Coal 25.9 Natural gas emits far fewer emissions than the other fuels

10. Cooling Data Have AC usage data by region for 1993, 1997, and 2001. Average proportion of energy used by region assumed to be constant over time. National energy use for a number of years given. Extrapolation and interpolation done on missing years.

11. Calibration Curves

12. Cooling Trend

13. Energy used for each state has been increasing overall. This increase is a result in increased number of houses and an increase in the percentage of houses that have AC. Some of the inconsistency is due to spotty national AC usage data. Also, an increase in AC efficiency will cause a decrease in AC usage if the number of households remains steady.

14. Suggested Changes Migration to the warmer states –Heating degree days far outweigh cooling degree days Increase people per household Change heating fuel Change thermostat setting Close off unused rooms