Eco-rate has analyzed various heating technologies to help you choose the most cost-effective and efficient system. Hover over the rating icons below to see our rating criteria; visit our How We Rate page for more details. We recommend you consider your local climate before making a purchase and contact a certified HVAC professional before installing the system. Note: ratings are based on averages and estimates for ENERGY STAR qualified models, 36,000 BTUH (output) for a 2,000 square foot home in a temperate climate (1834 heat load hours).