CEA Sealed Grow Rooms and Water Cooled Air Conditioners

air conditioning for growing hydroponics indoors

CEA Sealed Grow Rooms and Water Cooled Air Conditioners


Looking for consistent yields from your indoor hydropoinics crops, no matter how hot it gets outside this summer? CEA Sealed Grow Rooms and Water Cooled Air Conditioners have been a reliable answer for all types of growers.

[quote]Cooling requirements vary from room to room. Insulation, the air volume relative to the number of lamps, and the number of walls are all factors that play a role in sizing a water cooled air conditioner[/quote]


The modern CEA Sealed Grow Rooms and Water Cooled Air Conditioning can produce greater high yielding crops consistently in less space.


Increased sophistication in climate control can provide working parameters that were not achievable in the conventional grow rooms described in earlier indoor growing guides.


addison WC AC

Conventional “window banger” air conditioning discharges the hot air removed from the growing area to outdoors-this isn’t always efficient, especially since you are missing out on the chance to add efficient co2 enrichment to the growing environment for faster growth and heavier yields.

Air to Air ACs are also a very good choice, but may require some work and planning to install-however, companies now sell and ship pre-charged refrigerant lines. This makes it possible to do the install yourself or by an electrician with no HVAC specialist in attendance required.

Water-cooled air conditioning, as the name implies, requires a considerable amount of cool running water to operate. While the unit is operative, most models will require approximately 1.5 Gal of flowing water per minute. The principal behind using this type device for indoor and often subterranean growing environments is that the heat generated from the growroom goes down the drain with the water after flowing through the equipment versus ducting hot air to the outdoors in attempt to control growing environment temperatures. Ponds, rivers and other inexpensive sources of water are required to operate such units. When properly installed, the grower simply sets the temperature on their thermostat. The equipment is capable of maintaining exacting temperatures within a pre-set differential, typically 5°C. If narrower temperature differentials are maintained, the equipment is cycled more frequently. This is less efficient in water and electrical consumption.

Water cooled air conditioners tend to be as bulky as they are water and energy intensive. They can weigh into the hundreds of pounds, and may occupy valuable space ranging to refrigerator sized. However when properly crated with the aid of a hand truck they can be moved by two people with relative ease.


CEA Sealed Grow Rooms and Water Cooled Air Conditioners typically requires 240V or more for the power supply and a dedicated high amperage circuit breaker or fuse. A cold water supply will need to be plumbed from the pressurized source to the unit. Industrial grade hoses may simplify the installation. An added benefit for the grower is the appliance’s ability to remove moisture from the air (humidity) in the cooling process. This moisture collects in the drain pan beneath the condenser and must be drained freely away. Note: with proper installation and collection methods, this condensate from the crop itself, may be used as irrigation water; effectively re-cycling crop moisture. This procedure can be simplified with an industrial grade hose, but the machine must be higher than drain level as it is via gravitational flow. Some designs integrate air purification materials such as activated carbon into the air intake portion of a standard water cooled air conditioner. Restricting the intake may diminish the cooling efficiency of the machine.


Cooling requirements vary from room to room. Insulation, the air volume relative to the number of lamps, and the number of walls are all factors that play a role in sizing a water cooled air conditioner. Air conditioning is most efficient when operated in a well sealed and insulated room. Coupled with multiple H.I.D. lamps and propane or natural gas burning CO2 generators, cooling demands can be hard to obtain optimal growing temperatures.

Calculate your cooling requirements based on 4500 BTUs (British Thermal Units) per 1000W lamp. This factor helps provide a margin of buffering. Consult the chart detailing the cooling output of various units relative to the number of lamps per room.



Relative Cooling Output of  water cooled air conditioners for CEA Hydroponics

Max Lights






























60,000+ units usually require a 3-Phase power supply.

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If a water cooled air conditioner fails while lamps and the CO2 burner are operational, the room can get excessively hot. Past certain temperatures crop loss is inevitable, but there may be worse consequences including fire. As a precaution, it is recommended a high amperage relay be wired to the power being supplied to the H.I.D. lighting system. A line voltage heating thermostat is installed in the growroom and set to 95°F and wired to the relay to act as a trigger. If the temperature reaches greater than the set point, the lamps will shut off until temperatures are below the set point. In this configuration, the heating thermostat thinks the lights are heaters. So when the temperature rises above the set point, the “heater” (lights shut) off. This precaution has saved more than one crop with CEA Sealed Grow Rooms and Water Cooled Air Conditioners.



About Erik Biksa 247 Articles
Erik Biksa has been writing about and discussing hydroponics growing, related technologies and cropping methods since 1999 in a variety of professional publications and platforms globally Erik has travelled the world learning and teaching modern growing techniques and technologies and is appreciated by many growers for his informative yet hands on approaches. Presently, he is the Editor at Grozine Hydroponics Mag.