The most important reason to control the conditions of an experiment is to make sure that the environment is affecting the results of the experiment--which would void the study.
It is very important to control the conditions of an experiment because FAILURE TO DO THIS WILL MAKE THE RESULTS OF THE EXPERIMENT INVALID.
A controlled experiment refers to an experiment that is conducted under controlled conditions. Conducting experiments under controlled conditions helps scientists to minimize the changes in all other variables with the exception of the ones been tested.
