Controller Savings For The Smaller Grower

Controller Savings For The Smaller Grower

Many affordable controllers add settings
like DIF and night set-back.

A controller does not have to be elaborate or complicated to save you money and improve your crop quality. It does not have to control every operation of the greenhouse to be effective. Replacing thermostats with a simple controller that handles only the heating and cooling will save you energy and improve your crops. Many affordable controllers add settings like DIF, night set-back, humidity control and curtain control and still stay price competitive with thermostats. 

Single Temperature Reading

One of the greatest cost savings that a controller produces versus thermostats is from the coordination of heats and cools from one temperature probe. It is almost universal that growers will tell you that in a greenhouse with thermostats, you will, sooner or later, get heats and cools running at the same time. This can happen when the heat thermostat is located too close to an inlet or when a thermostat loses its calibration, causing overlap between the heating and cooling ranges.

A controller uses one temperature reading and compares this to a set point to decide if heating or cooling is needed. The temperature cannot be in both the heating and cooling zone, so only heating or cooling will be
active–never both.

Accuracy

The accuracy of a controller will also lead to savings. Inaccurate thermostats often cause the temperature to be higher than the dial setting, causing energy waste through higher heat loss. The accuracy of controllers also makes the staging of appliances effective by using only equipment needed to maintain the desired temperature. In fact, Mark Lugibill of Lugibill’s Greenhouses in Columbus Grove, Ohio, says when he originally installed his controllers, it took a little time to get used to the preciseness of the controllers because he was used to “sloppy thermostats.” 

Night Setback & DIF

Heat loss is a function of the temperature difference from the inside to the outside. Night is generally the time of lowest outside temperature, so dropping the night temperature (night set back) can save energy. Most decisions have trade offs. Be careful that your night set back does not affect your 24 hour average temperature so much that you extend your growing time and miss target dates. Raising your day temperature, when it is easier to heat due to warmer outside temperatures and solar gain, can help boost your 24 hour average temperature to compensate for the night set back.

Lowering the night temperature and raising the day temperature can lead to plant stretch so you can take advantage of the DIF feature of many controllers. DIF is the lowering of the temperature during the one to two hours just before sunrise. The early-morning drop of temperature can convince some plants to act as if the entire day is cooler than the night. This reduces stretch plus allows you to drop your temperature just prior to sunrise, which is usually the coldest time of the night. 

Additional Features

Losing a crop to disease is a horrible waste of energy and labor! Humidity control is the first tool in fighting disease by keeping leaves and surfaces dry. Manual humidity control with thermostats can be tedious, time consuming and inconsistent. First, you adjust the cooling thermostats to purge the humid air. Next, you adjust the thermostats to stop the ventilation and start heating to capture more humidity. Then you repeat the first step to exhaust more humidity. Lastly, you adjust your thermostats back to their original settings and hope they control at the same temperature as before. Controllers with a built-in dehumidification cycle make automated humidity control easy and consistent. The cycle is triggered at a consistent humidity level, runs without any manual adjustments and returns to precisely the original set point. Humidity control does use energy, but saving a crop by controlling the humidity can keep you from being penny-wise and pound-foolish.

Energy/shade curtains are great energy saving devices but hard to control manually. Matt Mohrfeld, of Matt’s Greenhouse & Flower Cottage in Fort Madison, Iowa, wanted to add an energy curtain and inquired about what additional controls he would have to add. He was pleased to find out the small controller he was using had the capability to extend the curtain at night with the timer and adjust the curtain during the day with an unused proportional output. When you are upgrading from thermostats to an affordable controller, make sure it has a timer function to close a curtain at night and a proportional output to move the shade curtain during the day.

Monitoring your greenhouse remotely with a computer interface is another indirect saving that controllers can provide over thermostats. Checking all your greenhouses from your desk or home will eliminate the cold, night-time walk to each greenhouse to check on the heaters and thermostats. You will know the temperature of each house without opening the door and letting more cold air in. Additionally, controllers generally have alarms to alert you of problems and prevent the awful surprise of opening a greenhouse and finding it frozen due to a heater that failed after your last check of the night.

A small, affordable controller can save you energy. “This is the best thing going for small growers,” Richard Bodfish of Bodfish Farms in South Haven, Mich., says of his controllers. Growers who have indicated that the system paid for itself in one growing season have attributed the greatest saving to not running heats and cools at the same time. The great thing about controllers is they are installed for energy savings, and then quickly become a growing tool that will help produce better crops. Schlegal Greenhouse in Indianapolis purchased a controller for the energy benefits but, Terry Christian, a grower there, also commented that they had the best poinsettia crop in 20 years thanks to tight control and DIF. A controller will not solve all your greenhouse problems, but a small affordable controller can start saving energy dollars, provide growing tools not available with thermostats and free up time that was spent continually adjusting thermostats.

Leave a Reply

More From Equipment...
Gaillardia x grandiflora 'Arizona Apricot'

February 25, 2015

National Garden Bureau Designates 2015 As Year Of The Gaillardia

Gaillardia, also known as the blanket flower, is a member of the sunflower family (Asteraceae) and a long-blooming pollinator plant. It is fitting that the National Garden Bureau has specified 2015 as The Year of the Gaillardia.

Read More
IPPS Sharing Plant Production Knowledge Globally Logo

February 25, 2015

International Plant Propagators Western Region Sets Annual Meeting Date

The annual meet for the International Plant Propagators' Society (IPPS) Western Region has been set for this September. It will take place September 23 to 26 in Modesto, Calif., and will include learning sessions, tours to local nurseries, a research poster display and poster presentations, various networking opportunities and an awards banquet to close the event.

Read More
Evolvulus Blue My Mind

February 24, 2015

Blue Ribbon Bloomers For Greenhouse Production

Grow what consumers want! Surveys show that blue is one of the top preferred colors of today’s consumers. Here are twelve top recommended blue-flowering Proven Winners annuals and perennials to suit your spring production cycle.

Read More
Latest Stories
Outfitting Your Greenhouse

February 24, 2015

Save Energy With The Right Greenhouse Glazing

The glazing you choose can make a big difference in your energy bill and the uniformity of your crops.

Read More
Michigan State University Extension

February 24, 2015

Ethylene From Defective Greenhouse Heaters Damages Crop…

Malfunctioning greenhouse heaters can lead to crop damage from ethylene and carbon monoxide induced illness for workers. Michigan State University's Extension educators Tom Dudek and Randy Beaudry teach you how to recognize the symptoms and check greenhouse heaters to avoid the concern.

Read More
Havest Automation Robot

February 18, 2015

Robots Grab Hold Of Growers’ Material Handling Needs

Harvest Automation’s HV-100 robots automate one of the hardest, most labor-intensive jobs at growing operations – plant spacing. With more technology coming, investing in robots could become even more realistic for growers of all sizes.

Read More

February 1, 2015

4 Lighting Products For Your Operation

These new lighting products have been developed for maximum energy efficiency in greenhouse production. Check out the slideshow to see which products are right for your operation.

Read More
LumiGrow

January 30, 2015

LumiGrow Expands Customer Base In 2014

LumiGrow, Inc. is adding more than 125 new commercial, governmental and research customers to its roster of customers, and beyond the new accounts added this year, many existing customers significantly increased the number of LumiGrow products they use and research customers made LumiGrow a part of their efforts to add to the body of knowledge about spectral science.

Read More
harvest automation featured image

January 13, 2015

Harvest Automation Extends Robot Rental Program

Harvest Automation's robot rental program proved to be such a success for the company that it is being extended through the spring. The program was unveiled last year as a way for customers to get started with HV-100 robots.

Read More

January 9, 2015

Innovations In Irrigation

Need help improving your irrigation? Check out these new products.

Read More

December 2, 2014

Hanna Instruments, Inc. Introduces pH Electrode With Bl…

Hanna Instruments recently released HALO, a professional pH probe with Bluetooth Smart (Bluetooth 4.0) technology that transmits measurement data directly to an Apple iPad running the Hanna Lab App.

Read More

November 24, 2014

Biomass Six Years Later: Would Pleasant View Do It Agai…

Pleasant View gardens installed its first biomass boiler six years ago and has added a second one since. Now it’s reaping the benefits of lower heating costs and dollars saved.

Read More

November 18, 2014

7 New Media And Light Products For Greenhouse Productio…

New media and light products cover a broad sweep of growing conditions.

Read More

October 21, 2014

GreenClocks New Generation City Farm Fitted With Philip…

Osaka Prefectural University’s new city farm, which has been fitted out with Philips LEDs, opened September 19.

Read More

October 1, 2014

Harvest Automation Introduces Robot Rental Program

Harvest Automation has unveiled a new introductory robot rental program as a way for customers to get started with HV-100 robots.

Read More

September 15, 2014

Precision Horticulture: What Piece Of Equipment Or Syst…

Let us know what product you can't live without.

Read More

September 15, 2014

New Products For Precision Growing

Increase efficiency with these new offerings in equipment, automation, structures and software.

Read More

August 12, 2014

LEDs Comparable To High Pressure Sodium Lamps For Cutti…

In his Cultivate'14 presentation on lighting the future of young plants with LEDs, Christopher Currey, Iowa State University, shared recent research on how LED lights stack up against high pressure sodium lamps for liner and plug production.

Read More

July 29, 2014

Bench-Top Root Zone Heating: Can You Reduce Air Tempera…

This is the second article in a two-part series featuring research from Purdue University that focuses on energy-efficient production strategies for annual bedding plants.

Read More

June 27, 2014

4 New Products For Cooling, Shading And Ventilation

The Vertex by Poly-Tex The Vertex is the newest member of the Greenhouse Megastore’s shade structure family. Make a statement and show your colors with this simple, stylish shade house.The easy-snap button frame and bungee-shade attachments will provide  shade in no time. With  more than 7 feet of sidewall clearance and 13 feet to the peak, the Vertex will give shade while keeping that open-air feeling.  

Read More

May 27, 2014

Philips Hosts High Wire Event For The First Time

Philips recently organized the International High Wire Event for the first time. The event was held in the Netherlands for a select group of international tomato growers, and included practical visits and opportunities for exchanging know-how and experience.

Read More