PROPORTIONS

To ensure the proper operation and performance of the fireplace, some proportions have to be respected. Most providers of industrial fireplace hearth and inserts will provide summary tables that can be used for the most common fireplaces; all these tables respect more or less the following proportions:

o The surface of the opening of the firebox (AxB) is 9 times the surface of the flue lining.
o The height of the smoke chamber (D) is the same as the height of the firebox opening (B).
o The height of the flue lining is equal to 7 times the height of the opening plus the height of the smoke chamber (B+D).
o The depth (C), height (B) and width (A of the firebox has to respect the ratio of 4,5,6 ; with C=4, B=5 and A=6.


With these simple rules, the dimensions can be defined from a single measurement. For example a flue lining of 25 cm will give a fireplace of these dimensions: 25 cm x 25 cm = 625 cm2.

So the opening of the firebox (AxB) will have a surface of 9x635 cm2 =5626 cm2

As given above, the ratio A/B is equal to 5/6 and AxB = 5626 cm2, so: 6/5 x B2= 5626 --> B = v(5/6x5626)=68,5 A=(68,5/5)x6 = 82,2

We know the ratio B/C is equal to 5/4, so: C = (4/5)x68,5 = 54,8

The height of the smoke chamber (D) is equal to the height of the firebox opening (B), so: D=68,5

The height of the flue lining (H) is 7 times the height of the of the firebox opening (B) + the height of the smoke chamber (D), so: H = (B+D)x7 = (68,5+68,5)x7 = 959 cm