Strutt|Building Acoustics|Room Constant calculates the room constant `R` and inserts it in the current row of the active sheet. The room constant can be used in the Reverberant Level (From Room Constant) calculation.
The room constant is calculated as:
`R=(S alpha_(ave))/(1-alpha_(ave))`
where:
`S` is the surface area of the room
`alpha_(ave)` is the surface-averaged absorption coefficient of the room