| X |
Width of the firebox opening
|
| Y |
Height of the firebox opening
|
| OL |
Distance to nearest obstruction or edge left of the firebox
|
| OR |
Distance to nearest obstruction or edge right of the firebox
|
| FF |
Distance between firebox and the finished floor
|
| RHH |
(If applicable) Height of opening for a Recessed Hearth
|
| RHL |
(If applicable) Length of opening for a Recessed Hearth
|