source: The exhaust gases could not be allowed to cool below a certain temperature, as there was a risk of the sulphur and nitrogen oxides in the flue gases condensing and forming acids which could have damaged the ID Fans.
target: The exhaust gases could not be allowed to cool below a certain temperature. There was a risk of the sulphur and nitrogen oxides in the flue gases condensing. The condensation would form acids that could have damaged the ID Fans.
references: The exhaust gases could not be allowed to cool below a certain temperature. There was a risk of the sulphur and nitrogen oxides in the flue gases condensing. The condensation would form acids that could have damaged the ID Fans.