Are steam baseboard heaters energy efficient?

The energy efficiency of a steam baseboard heater depends primarily on whether it is powered by an efficient central boiler system, with systems using modern boilers having far higher efficiency than those using older models. Design or maintenance flaws in the ducts between the heater and boiler also affect efficiency.

Average fuel use efficiency ratings for modern central boiler systems can reach up to 95 percent for direct-vent designs that burn natural gas or propane, with fuel-oil furnaces typically achieving a peak efficiency of 85 percent. By comparison, older designs often only achieve a fuel use efficiency of 65 percent in perfect working order.