One of the big benefits of a grow room is that you can create a tiny biosphere specific to your output goals. As noted above, plants use CO2 during daylight hours. If you choose to use a burner to boost CO2 levels, obviously daylight hours are critical to get the best results. Controllers can help you time when to
increase the heat
boost the humidity
move more air
enrich the CO2 levels
extend the hours of light exposure
In the controlled environment of a grow room, you can actually push your plants to boost the sugar or energy storage within the flesh of the plants. Flowering is process that takes a set amount of time, but light exposure can help you to convince the plants to start flowering and continue to store energy.
To make sure that your plants are getting the optimum care, carefully review the data you're getting from the different meters in your space. High levels of humidity and warm, moving air may be ideal at some points in the growth cycle of your plants. However, it can also turn your grow room into a haven for dangerous fungi, mold and pests.
Tracking the angle of the sun outdoors can also help you time the light exposure inside your grow room unless your space has an opaque lid. Because most growers use as much sunlight as they can get, you can extend your sunlight exposure with the right timer and climate controller.