The effectiveness of three measures of energy efficiency for furnaces has been demonstrated by comparison of the resu/ts for predicted energy savings against the cost savings predicted by the calculated total annual cost of operation using Department of Energy (DOE) test procedures. Two of the efficiency measures currently prescribed by the DOE--the annual fuel utilization efficiency (AFUE) and the DOE energy factor (EF) are pared with an industry-proposed energy factor--the seasonal energy utilization factor (SEUF).

Various parameters that affect the SEUF have also been demonstrated. These include the effects of power rating (wattage), burner input rating, electric to fossil fuel cost ratio, and the effect of annual fuel utilization efficiency (AFUE).