Smart Greenhouse Heating Saves Money

Switching from a thermostat to a computerized system keeps heating and cooling equipment from running simultaneously.

As the days get shorter and temperatures drop, it’s a perfect time to start thinking about how to reduce your energy consumption this winter. There are a number of relatively simple methods you can use.

The installation of thermal energy curtains has been popular in recent years due to the substantial energy savings associated with them. They can serve double duty in the spring and summer as retractable shade curtains.

Energy curtains can be expensive. For example, a grower installed a 40-foot-by-78-foot energy curtain for the price of $12,000. If the grower heats the greenhouse without the curtain from January 1 to May 31 at a temperature of 65°F, it would cost almost $24,000 to heat. With the curtain, it only costs about $17,000. At the time of installation, heating oil cost $3.10 per gallon. The grower saved about $6,600 per year, making the payback on investment in less than two years.

Insulating hot water pipes can be a very inexpensive way of conserving heat. According to John Bartok of the University of Connecticut, you can save about $5 per linear foot per year if you insulate a 0.75-inch pipe, or up to $16 per linear foot per year on a 3-inch pipe.

Thermostats have been used extensively in greenhouses over the years but can be inaccurate and can only run one system. This can result in your heating and cooling systems running simultaneously. Upgrading to a computerized system has become more affordable and can run both heating and cooling systems more efficiently.

Cleaning or replacing glazing also has a number of benefits: better light transmission, which results in less disease, fewer PGRs needed and higher-quality plants. Plus, newer glazing often allows better heat retention, which means lower heating bills.

Explore Alternate Energy Options

Wood heat is an option with an outdoor boiler and cordwood. Some growers are investing in large-scale wood chip burners. Be sure to work with your local governments and abide by local ordinances associated with burning certain alternative fuels. Boilers can be run at maximum efficiency 24 hours a day, which creates excess heat during the day and under-produces heat at night. The excess heat from a boiler can be stored in water and extracted at night. One pound of water will store about 1 BTU for each degree increase in temperature. For example, one gallon of water weighs 8.35 pounds. If it is heated from 60°F to 100°F, it is a change of 40°F. (8.35 pounds × 40 degrees = 334) This means each gallon of water can hold 334 BTUs.

While large tanks can store more BTUs, they are not a viable option
for most growers. A low-tech option is filling 50-gallon drums with water and placing them in an unused space in the greenhouse, such as under benches.

The water heats passively from the surrounding air temperature and
returns the heat back to the air as the temperature drops. This method
can help moderate fluctuations in temperatures.

Crop Scheduling For Savings

Taking the time to schedule your crops can have a dramatic effect on your heating bill. When scheduling, be accurate. Don’t second guess the weather and add in extra weeks of production to compensate for poor growing conditions. Write down your schedule and make it accessible to your staff. Make sure you stick to it.

Consider a crop grown for Mother’s Day in a typical poly house. If the crop is accurately scheduled, it should take eight weeks to finish. It will cost about $2,700 to heat the poly house. If the schedule is overestimated by just two weeks, it will cost $3,600 to heat it — a difference of more than $900 for just two extra weeks.

Stop now to plan ahead for the coming spring season. While no means an all-inclusive list to conserve energy and save money, I recommend starting with the low-hanging fruit by targeting things that are the easiest to implement and have a short payback on investment.

Leave a Reply

More From Equipment...

March 4, 2015

Nexus Corporation’s Cheryl Longtin Encourages Women To Seek Volunteer Leadership Opportunities

When Cheryl Longtin came to the horticulture business in 1994, she applied her experience in the automotive industry to promote the adoption of more technology in greenhouse production. Longtin says horticulture, with its rich family tradition, has long promoted women in the industry compared to other industries, but women in horticulture must continue to seek out opportunities to provide volunteer leadership in organizations that shape the future of the business.

Read More

March 4, 2015

Second Annual GreenhouseConnect Will Bring Growers and Suppliers Together in San Diego This October

Following a successful inaugural event in Tampa last fall, Greenhouse Grower has announced the dates of its second annual GreenhouseConnect: October 26-29, 2015. Representatives of an expected two dozen leading greenhouse operations from across the U.S. will join senior-level suppliers at Rancho Bernardo Inn in San Diego for several days of one-on-one strategic meetings, a growers-only roundtable, informational sessions and a variety of networking events.

Read More
cultivate'15 logo

March 4, 2015

Cultivate’15: AmericanHort Announces What’s New

In an industry that has seen major changes occurring at a fast pace, many industry professionals leave Cultivate with their heads spinning and no clear idea of how to regroup and strategize. Cultivate’15 is “Changing the Game.” As this year’s focus, Changing the Game will call your attention to the ways in which our industry has changed and your opportunities to compete successfully.

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