Mine is a dual fan fireplace insert with 2 slide dampers in the door. It originally had glass in the door but the glass cracked and the original owner had a steel panel welded in place. It takes up to 20 inch pieces of wood and was in the house when we bought it 32 years ago. It heats our den, kitchen, dining room and living room very well and I set the furnace fan on fan only and it draws heat into the far reaches of the house. I let the fire die down at night then rekindle it the next morning. I love the warmth of a wood fire occasionally but i’m glad I don’t have to depend on it as my main heating source. What’s your setup?