The Importance of Environmental Controls in the Modern Greenhouse By Yen Pham

The challenge in today's business world is to produce more at less cost. The greenhouse industry in this regard is no different than any other business. Historically, most greenhouse owners and managers were and still are a conservative lot. Of course, there are always the early adaptors, but for many it's "if it ain't broke, don't fix it" philosophy. So long as labor and utility costs are cheap, this philosophy may have something going for it. But times have changed and it is highly unlikely that these costs will reverse themselves.
Again historically, many greenhouse owners lived on the property with their business. A number still do. Some, it would seem, live as though they are tethered to their property, 24/7. When a storm passes through, they hurry out and close the vents. In the depths of winter before retiring for the night they visit the boiler room and most likely make a final tour of their greenhouses. Typically their children move some distance away and are not as inclined to want to get out of bed in the middle of a cold winter night, start the car, and drive to their greenhouses.

These are only a few of the situations where modern automated environmental controls can make a huge difference in one's business life style. But there are many other reasons also. We will highlight a few of them.

Improving Plant Quality
Perhaps foremost is improved plant quality and increased yields. By mimicking the plant's natural growing conditions growers will not only produce better plants but save energy as well. The controller assures accurate temperature and humidity readings, and permits automatic night setback temperatures with gradual transitions from day to night and the reverse. With the use of the controller's dehumidification control capabilities, the need for fungicide spraying is reduced resulting in stronger healthier plants. Various dehumidification strategies can be employed based on the greenhouse equipment and the outside environmental conditions.

Spraying with chemicals for plant disease and insect control is at times a vital and crucial part of a greenhouse operation. To eliminate employee risk, special care must be taken along with protective garments for the person doing the spraying. This whole problem goes away with the controller that now can be programmed to trigger a fogger
(perhaps in the middle of the night) and to setup the greenhouse conditions appropriately. For example, prior to activating the fogger, the fans go off and the vents get closed. After the fogging period, the HAF fans remain on to complete the circulation and then sometime later, the mechanical equipment is used to purge the air in the greenhouse.

Temperature Control
We already alluded to savings for fuel and electricity. Heating costs can take a big bite out of the bottom line. The single-zone temperature sensor eliminates the possibility of both heating and cooling occurring simultaneously. Dropping the nighttime temperature gradually to simulate natural conditions and its reversal in the morning will result in significant savings. The integration of all the electro/mechanical equipment in a greenhouse zone contributes to further energy savings. The CO2 injection only occurs when certain light level and temperature conditions are satisfied. The curtain can be used for cooling in addition to shading and the energy curtain is only engaged when outside temperature and light levels are met. These are only a few of the possibilities that could be listed.

A Labor Saving Tool
The modern environmental controller is a great labor saving tool. It frees up the grower for more productive activities — he or she can focus on growing. Once programmed, it runs on its own 24/7. For seasonal changes the grower can quickly replace the current program with one previously prepared that is stored in the controller.

In addition to an interface to a third-party alarm unit, the modern controller has the option to send alarm messages directly to selected cell phones, tablets and similar devices. Sensors other than zone temperatures can also be set to trigger an alarm. These might include boiler, pipe, floor heat temperatures, or sensors such as vent position or steam pressure. With one of the above "smart" devices, the user can check the operational details of the greenhouse equipment, i.e., what's on, what's off, and make changes as desired. What's amazing is that this can be done from virtually any location in the world.

Data Storage
While the controller is keeping the greenhouse environment happy, it is at the same time collecting and storing away useful data. It is data logging all the sensor information and keeping track of each piece of equipment as to its status. With a link to an office PC, the data can be down loaded, or if the PC is online, this occurs automatically and will provide information in graphical formats that can be extremely useful. For example data history can be used to correlate growing success with environmental conditions. Or the plants aren't doing as well as you would expect and from the data you have a good chance to figure out why.

How important are environmental controls in today's greenhouses? I would suggest that they are essential. If you, Mr. Grower, truly want to be competitive and build a sustainable, profitable greenhouse business with a bright future, you will want to automate. There are so many upsides and I can't even think of a downside.

Besides, isn't your time better spent with your family, friends and a trip or two to Hawaii without having to worry about what the weather is like back home?

The Importance of Environmental Controls in the Modern Greenhouse

Yen Pham

Yen Pham is president of Link4 Corp., Yorba Linda, Calif. For more information on this article, please call 866.755.5465 or e-mail