HD5 insert stoveThe HD 5 Black Insert Stove can be simply installed into a standard solid fuel fireplace opening, and can greatly increase the efficiency of your fire. Open fires can be as low as 20% efficient, with the majority of the heat escaping up the chimney. The HD 5 Black Insert Stove has an efficiency rating of 78. 5% making it an extremely efficient option. Reduce your carbon footprint Fewer toxins discharged into the atmosphere Reduces heat loss up the