Chimneys took a great leap forward in 1678 when Prince Rupert, nephew of Charles1, raised the chimney grate. This increased airflow greatly improving the efficiency of burning fire.
Fireplace grates provide many benefits and a roaring fire is one. As the logs rise from the floor of the firebox, air is drawn from under the burning logs creating a drain. This causes a cycle. Air extraction burns the hottest logs and the hotter the logs burn, the more it attracts. This makes the fire burn cleaner, which means less pollution and less creosote in the chimney, reducing the chance of a chimney fire. A hot fire also means more heat for you. When the grate is placed towards the back of the firebox, the heat hits the tilt of the back of the fire. The tilt of the back of the fire leans forward reflecting heat back into the room.
Another benefit of fireplace grates is that they securely hold burning logs in place so they don’t fall to the floor. This benefit should be obvious. The fireplace grates will also keep the burning logs compact, causing them to “feed” on each other rather than spread out and burn independently.
Fireplace grates also make it easy to light a fire. Just crumple up the newspaper and tuck it under the rack. Next, put firewood in the fireplace grate. On top of the chips lay medium-sized pieces of wood, and lay one or two logs on top. Presto, a full-size fire. The importance of the fireplace grate in all of this is to keep the weight of all the wood off the paper, which would suffocate it, preventing it from getting hot enough to light the wood.
When measuring your firebox for a grate, simply measure the back of the firebox. This is usually the narrowest point if the walls (sides) slope inward. Make sure there is at least 2-4 inches of clearance on each side. The fireplace grate should have 6 to 8 inches of clearance from front to back to keep it as far away from doors or screen as possible. Fireplace grates have a long history and remain so important today for many good reasons.