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What Should You Build Today?

Jennifer Zurko

“As the lingering effects of the recent recession fade away, we’re finding that our industry is back in an expansion phase, and growers across the U.S. and Canada are busily building greenhouses.”

This sounds like it could have been written recently, but surprisingly, that excerpt is from an April 1984 issue of GrowerTalks. Despite the economic difficulties, many growers are still investing in new structures. "I have not seen this much enthusiasm in about five years," said Jeff Warschauer, VP of sales for Nexus Corporation. "An early indicator is this winter’s trade shows, which have been very upbeat. So I think we have turned the corner."

Mark Davis, president of Atlas Manufacturing, shared similar sentiments. "Recently, I have seen an increase in requests for quotes and talk of expansion," he noted. "It wasn't as prominent in the last few years, but now, it appears positives are emerging." In 1984, growers aimed to save on building, energy, and labor costs—a goal that remains relevant. However, today’s growers are also environmentally conscious and future-oriented, looking at how new structures will adapt to an evolving industry.

Thirty years prior, free-standing greenhouses were more common. When manufacturers introduced gutter-connected structures, growers eagerly adopted them. These eliminated sidewalls, facilitating more organized labor and conserving heat. While this setup is still prevalent, modern growers seek more energy-efficient setups that save money and provide better plant environments. "Natural ventilation remains popular, and technology is enhancing such structures," Jeff explained. "The full open-roof, vented structure, often referred to as Venlo style, debuted in the U.S. in the early '90s. It provided a better environment for plants, reducing PGR use and energy costs without needing costly cooling fans or wet pad systems."

However, traditional open-roof greenhouses had drawbacks. They were costly to install and maintain, and produced inconsistent light levels due to multiple gutters. To address these issues, designers improved the “chimney vent”-style, which minimizes gutter use and supports wider structures. For example, a grower can opt for varied vent configurations in a 42-ft wide greenhouse:

• A “full” open roof with all vents opening (typically four peaks)
• A "partial" or "dual" roof with chimney vents opening at 50% (usually two peaks)
• "Single" with one chimney vent (one peak)
• Some hydroponic vegetable growers combine natural and mechanical ventilation to cut cooling costs when weather allows.

"Growers are consistently seeking ways to cut costs," said Mark. "Natural ventilation is less expensive to operate, and now, growers are requesting taller structures, previously 8-ft. or 10-ft., now 12, 14, 16 ft., or even taller. Taller houses simplify environmental control." Efficient motors and better controllers enhanced naturally ventilated greenhouses, triggering demand for heat-retention systems and energy-saving improvements, such as:

• Polycarbonate and acrylic coverings initially emerged in the 1980s with UV and IR additives, now offering different tints and multi-wall insulating values.
• Energy curtain systems and dual or triple curtains further enhance energy savings and adaptable, labor-saving automation in taller greenhouses.

"And don't forget grant money availability," Jeff pointed out, noting that grants from USDA, state and local agencies, and some energy companies help pay for efficient heating systems and curtains. "Higher structures with retractable shades and improved motors and controls offer significant benefits," Mark said, "and better energy consumption management is critical given it’s a substantial overhead budget item." Greenhouse manufacturers are also prioritizing environmental sustainability, with advancements like Nexus' double glazing system which doubles R value and maintains cooler summer conditions.

By stabilizing steel and aluminum pricing, heavily impacted by Chinese and Indian companies and economic fluctuations, U.S. steel manufacturers now offer more competitive pricing. "With interest rates low and borrowing easier, it’s an opportune time to invest in one's business," said Jeff.

In discussing future developments, Jeff mentioned, "Greenhouses and growing systems will adapt more to food production, with flood floors or benches supporting crop diversity, even in off-seasons." Mark observed similar trends with increased interest in hydroponic vegetable growing, driven by enhanced food safety awareness.

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