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Greenhouse Computer Equipment

In a Nepenthes greenhouse, computer automation equipment can make the difference between good growing and great growing. Computer equipment controls heating, cooling, humidity, and water. They can manage multiple heating and cooling equipment for day and night operation, and "step" from day to night and night to day. Stepping allows you to conserve greenhouse heat from the day and carry it into the night. It also keeps the heater from coming on if the sun has risen and will be heating the greenhouse in a short amount of time. This keeps energy from being wasted. Otherwise, it could be possible that at 8:00 am the heater would turn on, and by 8:15am the heater turns off and the cooling equipment has to kick in due to the sun heating up the greenhouse.

The computer can cause different equipment to work in unison. In larger greenhouses you'll have a heater, HAF fans, vents, exhaust fans, and swamp coolers. The computer can set when each of these turns on and off, opens or closes. Some computers also track when and how much a piece of equipment was operated. You can easily change the settings for each piece of equipment.

Some computers allows a communication interface to a PC. My greenhouse computer is set up this way. A CAT-5 cable is run from the greenhouse to my house where my PC is located. This PC has carbon copy loaded on it. Carbon copy allows me to dial into this PC from a remote location, which then allows me to operate the greenhouse computer.

Some computers also have alarms and paging capability to notify you if there is something out of toloerance. For instance, the computer can page you if the temperature rises above 95 degrees, which could mean that a piece of cooling equipment has malfunctioned. It could page you if the temperature drops below 45 degrees, which means the heater isn't working or that the greenhouse covering has been damaged. It can page you of the humidity drops below 40 percent, which means the water supply may have a problem. Fast notifications of problems allow them to be fixed before any major damage occurs.

A greenhouse computer allows the temperature and humdity to be tightly controlled, which results in better growing. Although usually expensive, they should be considered for large collections.

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Above: A view of the main greenhouse computer and contactor panel. Both systems are made by Wadsworth. The computer (open cabinet to the left) contains 12 relays, each of which control some piece of equipment. The line of relays can be seen as small square shiny boxes to the bottom of the cabinet. The switches and LED status are lined up above the relays, and allow manual control of the devices. The box to the right of the computer is the contactor panel. The contactor panel takes the low power signals from the computer to turn on high power equipment such as the exhaust fan, swamp cooler, main vent, etc. The main computer contains the equipment schedule, which controls (by software) when each device turns on and off.