Energy efficiency no longer sits on the back burner. The topic has become a hot potato as consumers and bakery customers turn up the heat when it comes to discussing oven emissions and a bevy of other burning issues concerning climate change.
Practically speaking, saving money has always been a hot button issue as baking and snack companies with thin margins seek to reduce overhead, so why not make the energy consumption a win-win issue for everyone involved before it boils over? That may be why many bakers asked about environmental and alternative fuel processes during the International Baking Industry Exposition (IBIE) in Las Vegas last year.
“Reduction of carbon footprint seemed to be on a lot of customers’ focus lists,” said Clint Adams, vice president of sales and marketing, Babbco and CBF Bakery Systems. “There are numerous baking and food companies that are focused and committed to future carbon-neutral processes, and the oven is an important place to start.”
For myriad global reasons, energy will remain front and center at the interpack and iba tradeshows in Germany this year. The interpack packaging and processing event runs May 4-10 in Düsseldorf, while the iba baking tradeshow will be held in Munich, Oct. 22-25.
“In addition to the issue of carbon dioxide emissions, our European customers have a risk of non-availability of natural gas, which does not exist in the United States, and are investigating alternative solutions to gas,” said Marie Laisne, product marketing manager, Mecatherm. “We will, therefore, focus our iba communications on sustainable gas substitution solutions: electrification of ovens, hybrid heating and energy savings.”
Scott McCally, president of Auto-Bake Serpentine and Hinds-Bock, both Middleby Bakery companies, noted bakers at IBIE last year were looking for sustainable alternatives as geopolitical pressures make the natural gas market pricing and availability unstable in several markets.
“Many are asking for dual-fuel options, including ovens interchangeably operated from gas or electric,” he said.
Overall, energy has emerged as an important factor when it comes to oven selection, observed Nicola Menardo, president of TP Food Group North America.
“While looking at markets such as western and northern Europe in recent times, for instance, issues such as low-energy consumption and sustainability requirements seem to be playing a role in equipment selection,” he said.
Perhaps the biggest burning question for bakeries involves which options are best for them. Replacing or even refurbishing ovens is expensive, although the return on investment can be improved by pairing sustainable options with eliminating bottlenecks or expanding capacity as a part of a broader, long-term capital spending project.
“Fundamentally, the throughput of an existing oven is limited by its size, relative to the baking time of the product,” Mr. Adams pointed out. “The key is to shorten the bake time.”
Because most plants do not have the luxury of disrupting production to perform extensive bake trials, he added, bakers can work in Babbco’s Innovation Center on improvements to formulations or the baking curve.
Reducing oven bake time can become an energy-saving option, especially in bakeries with space restrictions. Baker Thermal Solutions’ Rapid Bake oven combines hot, high-velocity air impingement with radio frequency (RF) technology to enhance efficiencies.
“We are using RF technology to help reduce bake times and the overall footprint,” said Clent Hollin, category sales account manager, Baker Thermal Solutions, a Middleby Bakery company. “That allows using fewer BTUs than previous models and significantly reduces the raw materials needed to build the larger ovens.”
Kevin Knott, technical sales manager, Bühler, suggested that convection technology typically provides a more thermal-efficient use of gas.
In fact, some cookie and snack producers can combine direct gas-fired (DGF) and forced convection heat to better control the baking curve during the critical first baking phase while efficiently removing moisture later in the process.
Such changes, however, should be thoroughly tested prior to making any changes to bolster throughput or save energy.
“It is so easy to think you can simply increase capacity by reducing bake time,” Mr. Knott said. “However, bakers must be careful not to change the flavor and texture profiles of the finished product by baking too quickly. Increasing the length of the oven by adding convection zones is the best way to increase capacity.”
Using heat recovery offers another alternative to explore. John Price, sales director, Spooner Vicars, a Middleby Bakery company, said the recovered energy directly pre-heats the oven burner combustion air from ambient up to 150˚C (300˚F) with 4% to 6% fuel savings possible.
He suggested heat recovery, which also provides primary heat for DGF ovens, offers easy maintenance with simple exchanger removal for cleaning or replacement.
The system uses a vertically downward exhaust pass, and condensate collection of baking volatile organic compounds ensures longevity of the heat exchanger, while a bypass option can extend its reliability.
“Our target is for it to be offered on all Spooner Vicars forced convection impingement and hybrid ovens in the foreseeable future,” Mr. Price said.
As part of its sustainability initiatives to manage oven emissions and energy usage, Reading Bakery Systems (RBS) builds its ovens with better insulation to minimize the conductive heat paths from the interior of the oven to the exterior, noted Shawn Moye, vice president of sales, RBS.
“We also use lighter weight oven belting, when possible, to help conserve energy and offer items like high-efficiency motors and heat reclamation systems that can assist by reheating the oven makeup air,” he said.
Ms. Laisne mentioned that Mecatherm designs ovens that minimize unnecessary fresh air from entering the oven. These ovens also rely on a thermal camera, during the first tests, to audit proper placement of different insulation layers and avoid thermal bridges to lower heat loss.
She pointed out that vertical ovens reduce body surfaces and support thermal efficiency, while convection heat optimizes baking times with lower energy usage, she added. That’s why Mecatherm recommends using convection as the main heating mode in vertical ovens or combining it with radiant heat throughout the oven or in a specific zone for systems having these two heating modes.
Other options, Ms. Laisne said, include modulating burners with software that regulates temperature precisely.
Auto-Bake’s compact convection oven also delivers several benefits.
“In a simple comparison of efficiency versus the traditional tunnel oven, an Auto-Bake Serpentine oven requires 91% less floor space and an average of 83% less oven chamber volume than a traditional tunnel oven,” Mr. McCally said. “This compact oven design bakes 10% faster using an average of 32% less fuel and only one operator for an entire system.”
This article is an excerpt from the February 2023 issue of Baking & Snack. To read the entire feature on Ovens, click here.