In Hot Pursuit Of Heating Trends For The Greenhouse

Heating system trends are likely to be the last thing on a grower’s mind. But with cooler conditions right around the corner, we’ve taken the liberty of doing some research. Read on as five manufacturers discuss new developments, popular products and the heating systems of the future.

Trend #1:High-Efficiency Equipment


Heating a greenhouse without breaking the bank is easier said than done. Luckily, manufacturers continue to focus on building better equipment. By investing in the latest technological advancements, growers should expect to achieve efficiencies above 90 percent.

“We’ve moved our efficiencies from 65 percent to 80 percent by making some product design changes,” says Modine Manufacturing Company Sales Manager Randy Mich. “Six years ago, we introduced the Effinity93 product line. These hydronic unit heaters are 98 percent efficient.”

Part of Modine’s success has come from enhancing the equipment by focusing on the greenhouse industry’s unique needs. Although this market comprises a mere 10 percent of the company’s total business, Mich says the company builds products that can hold up in the greenhouse before introducing it to the commercial side of the business.

“It’s easy to satisfy the needs of a warehouse, but in the greenhouse, the product needs to hold up against things like humidity, chemicals and years of usage,” he says.

For example, Modine’s Conservicore technology helps eliminate corrosion and withstands acidic condensate. The separated combustion design ensures the heaters use dry, clean air outside the greenhouse instead of heating the humid, chemical-filled air from within. These changes have resulted in better product longevity, which means growers can count on 25 to 30 years of consistent performance.

Modine isn’t the only company proud of its efficiency percentages. BioTherm, which produces tubing and aluminum heat pipes, helps growers do more with less.

“With the advent of low mass boiler technology, aluminum-finned pipes and alternative heating products such as our MicroClimate tubing, greenhouse growers are able to heat the same amount of greenhouse space with less pipe, less water and overall smaller systems,” says Key Accounts Manager Joel Rechin. “Further, as boiler technology advances, the same heat can be applied but at much higher efficiencies, like with the condensing boiler.”

Better boilers and condensing technology can help growers achieve 99 percent efficiency. The good news, Rechin says, is that these higher efficiency boilers now boast cascading systems and are available to large commercial operations.

Delta T Solutions is one company that supplies hydronic-heating systems with direct and indirect radiation types. The company’s product line includes the Infinite Energy 2 Condensing Boiler that, within certain temperature ranges, can achieve the much-discussed 99 percent efficiency.

“We heat the plants, not just warm the air that eventually rises out of the greenhouse,” says National Sales and Marketing Director Mike Kovalycsik. “Using a DTS-designed system can save at least 30 percent over a standard, forced-hot-air unit heater. That usually gets the grower’s attention. Hydronic heating promotes less plant disease, less watering and quicker and enhanced root growth.”

Trend #2: Improved Product Designs

In addition to increasing efficiencies, manufacturers are continually implementing small design tweaks to advance their heating systems. Delta T Solutions’ push to create better efficiencies involves reducing electrical costs: The company is developing new high-efficiency systems that will use pump motors with variable frequency drives.

Detroit Radiant Products, which manufactures separate component, combustion unit heaters in Michigan, also understands the importance of continuing to innovate. The company’s latest improvement is a finger-proof fan guard that comes standard. This guard protects employees’ fingers from the unit’s propellers and stops sunshades from falling into the heater and getting tangled.

Another design perk is the product’s indicator lights, which help growers troubleshoot problems without opening the cabinet. When both lights are illuminated, the unit is producing heat. If only the first light is illuminated, growers know everything up to that point is running, which helps them locate and identify problems. With respect to efficiency, Detroit Radiant Products focuses on the grower.

“The efficiency we shoot for is application efficiency,” says Vice President John Wortman. “If you have a unit that produces 250,000 BTUs, you’re equipped to meet the demands of the coldest time of the year. The rest of the time, the unit is likely being overused and over-cycled.

“We would recommend two 125,000 BTU units, which allows the grower to use zoning as an application efficiency measure,” he says. “One unit can be used in the spring and fall, instead of blasting a ton of heat in from the one larger unit. We’re trying to educate the industry. There are so many misunderstood beliefs that you need the efficient units, and we say you need to get the application efficiency down.”

Across the board, manufacturers say they continue to see heating systems that give growers greater control. As with most greenhouse equipment these days, the technology is increasingly becoming Wi-Fi-enabled and integrated with other systems.

“We see this as the future,” Wortman says. “Smart technology makes it easier for growers to manage zone efficiency. With web integration, managers can view multiple heat zones and heaters at once. Someone may forget to turn off the heater, and it might be on for a day or two without anyone noticing. With occupancy sensors, you won’t accidentally run the heat when you don’t mean to.”

Trend #3: Alternative Fuel And Energy Types

When it comes to cutting costs, heating equipment can only take growers so far. Fuel materials are often partly responsible for slashing savings. Hurst Boiler, which recently developed a streamlined, simplified line of biomass boiler systems that range from 1.5 million BTUs to 8.4 million BTUs and don’t require expensive sensors and controls, is looking to give growers options.

“Right now, the main push is diversification of fuel types,” says Gene Zebley, who manages biomass renewable energy system sales. “Traditionally, biomass boilers run on wood waste, but there are a lot of other waste streams that are viable replacements for wood waste. We’re using pecan-shell husks from pecan processing plants, agricultural waste from food processing plants and agave waste from tequila distilleries.”

To use these alternative fuel types, Zebley says growers would need to make some manual adjustments to their boilers, but Hurst systems are generally less sensitive to fuel quality.

Manufacturers are also interested in geothermal energy as a means of cutting costs and improving efficiency. Modine, for example, is exploring this option and is in the very early stages of having a geothermal product line.

“I think this is a product line that will be very important to growers,” Mich says. “They put a lot of their efforts into root-zone heating. Geothermal is a way to follow those heating requirements because the temperature in the ground facilitates heating — and cooling — to the greenhouse. To compare this heating mode with traditional heaters, geothermal heaters are more than 300 percent efficient.”