Retrofitting Options

Retrofitting Options

Retrofitting a greenhouse is all about spending money to save money. In many cases, increased energy efficiency may be the easiest way to see new technologies impact the bottom line. However, the benefit of improved crop performance should not be overlooked as a factor in the bottom line savings (or rather gains)–from faster turns and fewer chemicals to improved labor conditions and reduced disease potential.

Though there are numerous components of a greenhouse where retrofitting may result in greater efficiency, this article will focus on those that influence temperature and light.

Shade Netting

For years, shade netting was available in black with the amount of shade determined by how tightly knit the fabric was woven. The purpose was primarily to reduce heat or light. Over the years, new colors have been introduced, including an aluminum covered fiber, in an effort to manage the light while reducing the heat.

Frank Giglia, general manager of Signature Supply in Lakeland, Fla., explains, “Plants photosynthesize all day, but they only grow when the temperature range is between 60ºF and 100ºF.” In most parts of the United States, summer greenhouse temperatures can easily exceed 100ºF. Aluminet 50 percent, a specialty shade netting, can decrease the temperature by 20ºF, while only increasing the shade factor by 10 percent. Rather than blocking the sun’s light, the aluminum-coated weave disperses light over the plant canopy.

ChromatiNet is a line of colorful fabrics available in red, blue, gray and pearl. The red and blue fabrics specifically address the wavelengths of the light spectrum that affect plant growth and development. Red, for example, increases the diffused light spectrum to 600 nm and higher, maximizing photosynthesis and leading to faster overall growth. On the other hand, ChromatiNet Blue increases the light spectrum in the wavelength range from 425 to 490 nm, contributing to a reduced growth rate (eliminating the need for a chemical growth regulator) and delay of blooms.

The beauty of the colored shade nettings, besides their color, of course, is their ability to match your cultural needs. Giglia used two Florida growers as an example. Both grow New Guinea impatiens, but their growing environments are tweaked with different ChromatiNets to produce the best product for their customers. One grower uses blue to produce compact plants with lots of buds for landscapers. The other grower uses gray to get blooms as soon as possible so the plants can be shipped to Target.

In either case, a shade netting is a simple retrofit as an exterior covering. It is recommended as a year-round structural component in the southernmost states, and a seasonal addition in northern climates. The shade nettings last four to five years and cost around $0.21 per square foot. For more advanced light manipulation, the Aluminet and ChromatiNet coverings can be used in combination. 

Under ChromatiNet Blue, plants grow more compact with
darkerfoliage–desirable traits for foliage crops such as this
spathiphyllium. Blooming is delayed until plants are removed
from this ChromatiNet so blooming occurs at the
customer’s location.

Energy Curtains

Heat retention curtains have been the biggest category of increased sales in the past year for BFG Supply Co., Burton, Ohio, according to John Urbanowicz, technical service/product manager. Not only do the curtains provide 20 to 40 percent heat savings in the winter, they also provide cooling shade in the summer.

Urbanowicz says that for new builds, the curtain has become a standard feature. Retrofitting a house with a curtain may require some structural upgrades. Patricia Dean, vice president of customer relations at Wadsworth Controls, Arvada, Colo., agrees that the initial build is “the ideal time to install a curtain system.” Wadsworth also has seen a tremendous number of retrofits in the past several years.

The USDA offers a downloadable energy calculator, called Virtual Grower, on the Web (www.ars.usda.gov/services/software/download.htm?softwareid=108). Dean suggests growers use this tool to input their house dimensions, fuel consideration and temperature settings to assess their potential savings by installing an energy curtain. Simply run one calculation without checking the energy curtain box, then run a second calculation with the energy curtain box selected. The difference will help growers determine the potential benefit of a curtain system for their facility. Generally, Dean has found that the return on investment occurs in less than three years. Wadsworth promotes the rack and pinion system over the drum and cable system. Dean explains that the system will last seven to 10 years. With no cables to re-tension, the only maintenance (and therefore additional labor costs) associated with the curtain system is annual lubrication.

Dean warns that the labor to install the curtain system can cost as much as the curtain itself, though. Growers with construction experience may forego professional installation, but Dean and Urbanowicz suggest, at the very least, someone with installation experience should be hired to supervise and lead the project.

Urbanowicz cites 54 to 57 percent shade curtains as ones most commonly used by BFG customers. In addition to the typical shade fabrics, Dean also mentioned clear curtains, which allow for all day sunlight penetration while the curtain remains closed to retain heat in the winter. Another specialty curtain is made from open weave fabric that provides shade in the summer but lets heat escape through the curtain to the open roof vents. 

Glazings

Greenhouse glazings occasionally need to be replaced, and it’s a prime opportunity to investigate the latest innovations available. Polyethylene films are now available with anticondensate properties and increased thermal retention. Thermal films are more costly, but have the potential to reduce rising heating costs. Urbanowicz reports that a double layer of thermal film does not double the heat retention. Instead, many growers are choosing to use the thermal film as the exterior layer and an anticondensate film on the interior to maximize the benefits of both technologies.

As for acrylic glazings, DEGLAS recently introduced Highlux High Impact acrylic sheets that offer more optical clarity by having fewer interior sheet ribs. The ribs are spaced 96 mm (3 ¾ inches) apart, which equates to one third the number of ribs in 16 mm acrylic. Acrylic has long been valued for its high light transmission, but it also offers tremendous weather protection, particularly from hail damage, heat retention and an anti-condensate coating.

In addition to energy savings, shade nets, energy curtains and glazings contribute to improved crop quality, increased worker comfort, decreased water use and humidity and condensation control. In most cases, however, the fuel dollar will dictate the feasibility of retrofitting a greenhouse with energy saving technologies.

Leave a Reply

More From Structures...
Shane-Nitschke-Rough-Bros

April 11, 2018

Rough Brothers’ New Sales Manager Eager to Use Design Experience to Help Growers With New Projects

Shane Nitschke, the new Sales Manager of Rough Brothers’ Southeastern region, says his previous experience in commercial design will be a valuable resource in helping growers carry their own greenhouse vision to reality.

Read More
Greenhouse-retrofit-with-Reglazing-2

April 10, 2018

How to Decide Whether to Build a New Greenhouse Structure or Retrofit an Existing One

Is it time for you to update your greenhouse structure? Follow this tips from L.L. Klink to help you decide whether it’s better to retrofit an existing structure or build a new one.

Read More

April 5, 2018

Building Custom Solutions With L.L. Klink

Through its vertically integrated family of businesses and collaboration with greenhouse manufacturers and equipment suppliers, L.L. Klink Greenhouse Solutions works with growers and institutions to design, build, maintain, and furnish greenhouse structures.

Read More
Latest Stories
Shane-Nitschke-Rough-Bros

April 11, 2018

Rough Brothers’ New Sales Manager Eager to Use Design E…

Shane Nitschke, the new Sales Manager of Rough Brothers’ Southeastern region, says his previous experience in commercial design will be a valuable resource in helping growers carry their own greenhouse vision to reality.

Read More
Greenhouse-retrofit-with-Reglazing-2

April 10, 2018

How to Decide Whether to Build a New Greenhouse Structu…

Is it time for you to update your greenhouse structure? Follow this tips from L.L. Klink to help you decide whether it’s better to retrofit an existing structure or build a new one.

Read More

April 5, 2018

Building Custom Solutions With L.L. Klink

Through its vertically integrated family of businesses and collaboration with greenhouse manufacturers and equipment suppliers, L.L. Klink Greenhouse Solutions works with growers and institutions to design, build, maintain, and furnish greenhouse structures.

Read More
GrowSpan-Series-500-Tall-Greenhouse-GrowSpan-feature

March 30, 2018

The Latest in Structures: New Greenhouse Systems Offer …

Structures manufacturers and suppliers say their grower customers are asking for new models that can accommodate a diverse crop mix, while providing flexibility in design, maintenance, and control of the environment. Here’s a closer look at some of the latest options.

Read More
Greenhouse-Snow-Load

December 18, 2017

How to Make Sure Your Greenhouse Can Withstand Heavy Sn…

Heavy snow loads can cause greenhouse structures to collapse if proper snow removal techniques are not practiced or extra support is not provided.

Read More
Adding-Heat-to-a-Greenhouse-GrowSpan

November 15, 2017

Tips on Adding Heat to Your Greenhouse for the Winter

Heating your greenhouse for the winter is important, and choosing efficient equipment and designs can help you quickly get returns on your heating investments.

Read More
Smart-Magenta-Greenhouse

November 14, 2017

Smart Solar Greenhouses Designed to Generate Energy and…

Research at the University of California Santa Cruz has shown that the first crops of tomatoes and cucumbers grown inside electricity-generating solar greenhouses are as healthy as those raised in conventional greenhouses.

Read More
BrightFarms Ohio

October 18, 2017

Leafy Greens Grower BrightFarms Building New 120,000 Sq…

The operation will provide locally grown salad greens and herbs to supermarkets in the Cincinnati, Dayton, and Columbus, OH, metropolitan areas.

Read More
Rough Brothers HopsHouse

October 18, 2017

New Greenhouse Aimed at Hydroponic Hops Producers

The new greenhouse model is the first single-solution hydroponic greenhouse for year-round hops growth, and harvests anywhere from two to five times a year.

Read More
GVZ Glasshouses

October 12, 2017

How to Deal With Common Greenhouse Maintenance Issues

The most common problems often come from a lack of cleanliness and faulty equipment. Here are a number of tips you can follow in each of these areas.

Read More
Youngs Greenhouse Space Growing Feature

August 14, 2017

How Young’s Plant Farm Invests in New Structures and Eq…

The Auburn, AL-based Top 100 Grower operation is improving its production infrastructure so it can continue to efficiently produce quality plants and keep up with demand.

Read More
CS3 Greenhouse (Stuppy)

June 4, 2017

7 Factors That Can Determine the Cost of Building a New…

Want to know the main factors that determine the cost of building a new greenhouse? Phil Bishop of Stuppy has put together an overview of the expenses involved in this type of project.

Read More
Dallas Johnson Greenhouses

May 28, 2017

Growers Offer Advice on What to Know Before Your Next B…

Two Top 100 Growers discuss their most recent building projects, the challenges they addressed, and what they learned during the process.

Read More
GGS Cannabis Production

April 19, 2017

Suppliers Can Offer Technical Solutions for New Cannabi…

Here’s a look at how a few manufacturers have partnered with growers to make their transition into cannabis a smooth one, whether it’s through hands-on guidance or partnering with other industry leaders.

Read More
GrowSpan Series 1000 Greenhouse (GrowSpan) feature

March 24, 2017

New Greenhouse Structure Models Emphasize Crop Protecti…

Manufacturers of new structure models say they are responding to grower concerns with designs that focus on ventilation, maximizing your space, and incorporating a wide range of crops. Here’s a look at some of their latest offerings.

Read More
Brian Munchel

March 18, 2017

Brian Munchel of Ludy Greenhouse Manufacturing Dies at …

Munchel, a long-time member of the National Greenhouse Manufacturing Association, worked at Ludy Greenhouse Manufacturing for more than 30 years and was a computer-aided draftsman.

Read More
Nexus Atrium for Prides Corner

March 15, 2017

How Tech Suppliers Are Helping Growers Find Solutions

Greenhouse structures and components manufacturers highlight some of their most recent projects.

Read More

February 15, 2017

Growers Planning to Invest in Structures in 2017

Data from this year’s Greenhouse Grower State of the Industry survey indicates that growers are planning to make major investments in structures and facility upgrades this year.

Read More