Cutting costs of production is on the mind of any gardener using hydroponics, whether it's the cost of energy (electricity) or the use of water, which you have to pay for as well. Setting up a dual room operation means you can use one OptiClimate air conditioning unit to service two spaces at the same time and potentially cut your energy and equipment costs. You'll need the 3 Way Valve to get this set up. The valve connects to the OptiClimate unit's air outlet so the unit's output is split into each room. With an additional temperature sensor you can keep a close check on both your day and night rooms at the same time. You will need a plenum box as well to connect to the OptiClimate's air inlet, and when you get everything set up you can cool two rooms around the clock.