It is possible to build a fireplace fire on the hearth floor of the fireplace. This fire, though, will not burn as well and long because a fire needs a great deal of air. An open fireplace needs 250 – 350 m3 of air per hour.
Better ventilation and burning. In order to let the fire burn better, fires have been elevated for thousands of years with andirons. The first purpose of andirons is thus that by raising the fire, the air can get to the fire from all sides, so that it burns better.
Through the 15th century, andirons were mostly a single rod or block with one or two elevations. Those elevations served to prevent the wood from rolling out of the fire, the second purpose of andirons.
Starting in the 16th century, people started using andirons in pairs, which made the ventilation of the wood even easier.
Over the course of the 16th and 17th centuries, the design of andirons or firedogs was further adapted to practical needs that go along with cooking in and around the open hearth:
- -spit hooks were added so that foods could be grilled
- -bowls were attached to the top so that people could warm food or keep it warm
Starting in the 16th century, more attention and effort was also put into the decoration of andirons, as real status symbols. Whereas they were mostly made of iron until the 17th century, starting in the 17th century, they were decorated with bronze and/or brass, which was scarce and expensive at the time. As an addition to the dark iron, it made a beautiful contrast in the fireplace fire.
The cooking functions of andirons are no longer relevant, except for a limited group of hobbyists. But the other three functions have remained unchanged, to wit:
- -the improvement of the ventilation of the wood; poor draw in an open fireplace can significantly improve due to the use of andirons, whether or not with a fire grate
- -the prevention of the wood rolling out of the fire; all andirons have an elevation on the front for this purpose
- -decoration of the fireplace
The same effect can be achieved by using a fireplace grate or fire basket in stead of andirons. Both have advantages and disadvantages.
Advantages of andirons over a fire grate is that they made larger fires possible and that the size of the fire can be adjusted by moving the andirons closer or further away from each other. The advantages of a fireplace grate can be that a fire is more compact, often burns just a bit higher than with andirons, and that it is harder for the wood to roll out of the basket.
More about andirons and fireplace grates: