Why are Reliant products less expensive than other brands?
It’s because we came into the industrial oven market with a fresh approach to the design, manufacture, and distribution of equipment. We price our products based on what it costs to build them, not on “what will the market tolerate?” We’ve invested in high-end manufacturing equipment, but we don’t have fancy offices or a showroom for our products. We save our customers even more money by cutting out layers of middlemen that don’t really add any value.
Reliant customers have been buying our ovens for curing, drying, heat treating, and other applications since 2005. Their comments about the price and performance of our ovens have been amazingly positive. The cost savings from using our ovens have been well documented. We’ve gotten very impressive feedback from our customers, particularly those who have a competitor’s oven installed next to ours in the same plant. But, over the years we’ve consistently been asked to explain in plain language why our ovens are so affordable and efficient.
The answer is pretty simple: We can sell for less because ovens are our specialty. We’re the fastest-growing industrial oven manufacturer in the U.S. Although we’ve only been in business since 2005, we have hundreds of walk-in sized ovens in operation around the world. Our ovens work better because they have an innovative, highly-efficient design and our heat systems are built from premium components that have been configured specifically for use with our ovens. When you deal with Reliant, you get high-performance equipment straight from the factory that built it—and you talk with experienced specialists that can literally look across the plant and see your equipment being made.
Why are ovens from Reliant so much more efficient?
Because the technology used in our ovens is superior in two key ways:
1. Our conventional gas-fueled ovens utilize a heat system where the flame is blasted directly into the air stream entering the oven. The heat transfer is much more effective than in indirectly fired systems that use heat exchangers or less expensive direct-fired heat systems that use trough style burners where much of the air is not fully impacted by the flame. Because our heat unit has a large, symmetrical combustion chamber and the fan cycles a large volume of air directly past the flame at a lower velocity, more air is being directly heated at any given time. This reduces the amount of fuel required to heat the oven and shortens the time it takes for the oven to reach operating temperature.
2. On our conventional gas-fueled ovens, our controls allow the heat system to “learn” how much fuel is required to heat the oven to the target temperature. Through automated tuning and custom calibration, we are able to prevent the dramatic overshoot and constant cycling that some other ovens demonstrate. Also, because we have faster moving motorized gas valves with high turn-down ratios, extremely high-output fans, forced induction burners, and more sophisticated control devices, our heat units are much more responsive—making our ovens very stable and fuel efficient.
Some competitors use confusing jargon or “theoretical” terms to avoid answering the hard questions about their ovens. We strive to make our information accurate, easy to understand, and based on real world tests instead of sales hype. Our efficient, high-performance designs have been recognized by customers around the globe.
It has been observed that, when compared to our ovens, many other brands need a great deal more time to reach curing temperature and bring the material being heated up to temperature. In a batch environment, that means that the cycle time (not including cool down) can be up to twice as long as ours. Interestingly, most similarly sized ovens from other manufacturers use burners that are larger than ours in terms of maximum output in order to make up for their less efficient design. When the competition uses a larger burner, the cost savings with Reliant are even greater. In fact, a full curing cycle on a competing oven may not only take longer, the operating costs can be more than double that of a Reliant oven.
Some competitors claim to have precise air/fuel mixtures that are “self-adjusting” due to factors like the venturi effect. These methods are less effective at the root level than those used by our computer-controlled burners.
Some competitors make misleading comments about “enrichment” and fail to explain that heater output is directly related to fuel use. There is a difference between heater output and overall oven efficiency, but this is often confusing to the customer. If our heater has a 750,000 Btu/hr burner and theirs has a 1,000,000 Btu/hr burner, then it should make sense that no matter how much oxygen (and the corresponding amount of fuel) we pump into our device, it CANNOT use more fuel than theirs at maximum output. All heaters have a heat output rating that is based on their maximum fuel flow rate. This has NOTHING to do with the performance or fuel efficiency of the appliance. There MUST be a reason that our equipment gets to temperature faster than our competitors’ while using significantly less fuel. It’s because all Reliant heaters are custom configured for the application at hand, and have much greater “designed-in” efficiency and heating performance—which is why we typically use smaller burners than our competitors. Our ovens get to curing temperatures faster while offering better convection performance.
What are the oven structures made of?
Reliant ovens are built of G-90 galvanized steel, premium aluminized steel, or various types of stainless steel. All of our steel is prime domestic stock. There has been an influx of sheet metal from overseas that is sold simply as “galvanized” because it does not meet common industry standards. Even worse, inexpensive imported steel is also commonly thinner than the standard gauge thickness, so panels may actually be too thin to meet code. A recent surge in the use of “second” quality, non-prime metal stock has also been observed. Surprisingly, some established manufacturers still choose to use mild steel of unknown quality and simply paint over it. Although this material is much cheaper to use, the end-product will not be as durable and moisture resistant as equipment built from true U.S. prime treated or stainless steel. There has also been a rise in the use of low-cost “paintable” aluminized stock (often called “paint lock”). This material’s textured surface traps dirt and can increase contamination issues and shorten maintenance intervals.
Where are the ovens manufactured?
Reliant ovens are all designed and manufactured in the United States at our facility in Somerville, Alabama. Over the past few years, some finishing equipment and industrial oven companies have chosen to source their major components from foreign suppliers that provide products that are less expensive–but poorly made and very poorly supported. Some competitors have set up offices in Mexico, and others have partnered with Chinese and Korean manufacturers that specialize in cheap versions of popular products. Our designs have already been knocked off by competitors looking to cash in on our success, but we won’t compromise on component quality just to improve our bottom line.
How do the oven panels get fastened together?
Our ovens typically utilize bolt-together construction via pre-punched holes instead of relying on pre-fabricated panels that are butted together after being slid into a small track. This assures the ruggedness and airtightness of the oven once it is assembled, plus it makes the oven structure more rigid—yet better able to absorb damage. We’ve compared forklift “oops” damage on our ovens with similar damage on ovens that use slide-together panels. Repairs that would take days on theirs can be made in less than a day on ours. Butt-together oven panel assemblies are also noted for sometimes requiring extensive field modification for good panel to panel fitment if the floor is unlevel. Our ovens use a two-row redundant fastening pattern for extra-snug panel fitment, even on imperfect floors. We provide genuine Fastenal brand fasteners, including premium zinc-finished or stainless 5/16” flange nuts and flange head bolts. The assembly process is fast and the quality of fitment is outstanding. After years of operation, this can make a big difference in terms of maintenance and safety. Slide-together panels can develop gaps which reduce the heat retention of the oven and increase fuel costs. Also, because our panels are insulated in the field, there is no chance of insulation settling during shipping—a common issue with pre-fabricated panels.
Is there anything unique about the oven “box” itself?
The oven “box,” which we refer to as the “cabin” or “oven enclosure,” is bolted together, but it also has a floor track system and a roof track system. These tracks keep the panels aligned and assure extremely tight panel-to-panel fitment and minimal heat loss. All oven panel flanges, floor track/roof track sections, and corner joints include multiple rows of redundant holes on 6” or tighter centers. If the installer encounters an issue with an unlevel floor or other factors that cause the panels to not mount perfectly, he can use additional bolts in the problem area and improve panel fitment. Our basic cabin has 6” thick wall panels, and some models have panels up to 9” thick. Many other ovens on the market have only 3”, 4” or 5” thick wall panels. Our roof is also the same thickness as our walls, while other ovens may have roofs as thin as 2”-3”. We use 6# density or heavier genuine Rock Wool brand mineral wool insulation shipped from their facility in Alabama. Many companies only use 4# density, so their panels have a lower R-value. Some rely on cheap mineral wool imported from China that has very poor consistency and an even lower overall R-value. Our doors and our heaters are also packed with 6# or heavier insulation. Our standard doors are over 5” thick, versus as little as 2” with some competitors’ doors. There are also overlapping 3” door “lip” flanges that assure heat retention where the doors meet. Our oven cabins retain heat better than most comparable brands, saving the operator money.
How does the heat system work?
The 1973 Oldsmobile was probably a fine car in its day. But if it was being sold today for $10,000 more than a car that performed like a Corvette and got the gas mileage of a Prius, the Olds wouldn’t be a hot seller. That is a pretty good analogy for the difference in technology between our ovens and the ovens built by some of our competitors. We use forced-induction, direct-fired heating. A flame heats the air stream directly and cool oxygen-rich air is injected at the combustion point to assure that efficiency is maximized. We are often asked about “old technology” heating methods, like those used in boilers and industrial furnaces. The burners we use now weren’t around back when the boiler and furnace business was in full swing. Many boiler, furnace and oven designs have changed very little since the 1950s. Our ovens include innovative, money-saving features and new technologies, yet sell for thousands less than brands that use unremarkable designs and outdated components. The slot-fired burner is one type of older burner that is popular for use in less expensive ovens and heated wet paint curing booths. Although fairly reliable, these burners don’t perform as well as ours for oven applications. The burner configuration we use significantly improves oven performance and costs roughly twice as much as units used by some of our competitors–yet our ovens sell at lower price points. Even on our standard oven models we typically use American-made Power Flame FD-series burners with the unique “Jet Fire” upgrade. This type of burner is sometimes used by European manufacturers on their high-end products for the North American market, and a couple U.S. companies offer them on their most expensive models. A handful of boiler, furnace and oven companies also now offer burners similar to ours as upgrades on their appliances. Our heat systems consistently represent a better value than other brands.
How does the hot air get from the heater to the object being heated?
Our ovens offer extremely uniform heat distribution and very rapid substrate heating. We typically use a fully insulated overhead plenum with discharge holes located around the perimeter of the oven where the walls and ceiling meet. Hot air fills the oven from the ceiling down. This unique design significantly improves “real world” oven performance. Most batch oven operators load their parts onto wheeled carts that are rolled into the oven. Most large-scale process ovens rely on overhead conveyors. In both cases, the parts being heated are suspended off the floor. So why do our competitors typically use floor-mounted discharge ducts in their ovens that blow dirt off the floor and blast hot air onto the ground–instead of focusing on the area of the oven where the parts are hanging? Most other manufacturers install massive sections of ductwork on the floor and mount them against their ovens’ interior walls. This ductwork protrudes into the oven’s interior, forcing their customers to waste several feet of valuable floor space while paying to heat the “dead” space around the ductwork that cannot easily be used for curing parts. Depending on the model purchased, the customer either has much less usable space (particularly compared to the size of the oven’s footprint) or has to heat several cubic feet of useless space around the ducts. The wall-mounted duct design also leads to a “hot spot” in the center of oven. Because heated air is not being discharged in critical areas (just inside the doors, in the corners near the ceiling, etc.) the oven’s usable curing space is reduced and the oven’s performance can vary with objects of different sizes and shapes. Over only a few months these shortcomings can dramatically increase the cost to operate the oven.
How does heated air cycle back through the heat system after it has been heated and discharged into the oven?
Our heater discharges heated air directly into an overhead plenum instead of routing it through a maze of ductwork. The pressurized hot air is then forced through the oven cabin, and the majority of it is drawn back into the heat unit via a flush mounted floor level intake. This intake is located away from the exhaust system. The fact that the recycled air going back through the heater and the exhausted air being ducted outside gets directed to opposite ends of the oven helps assure uniform heating. Also, unlike almost all other designs on the market, the air being drawn back into the heat unit is at the floor—not the ceiling—so it is the coldest air in the oven. Many other brands draw in air at the ceiling, discharge it a few feet away, and create a “short cycle” where a small amount of air gets super heated while the rest of the air in the oven remains much colder. This can lead to measurable striation within the oven, often with multiple temperature layers that vary by up to 50°F from layer to layer. Our ovens typically have maximum temperature variations of less than 10% over the interior workspace at operating temperatures around 400°F. As an added bonus, the interior of our standard oven is smooth, with nothing protruding into the workspace. Although it may not seem like a big difference, almost all other brands on the market charge a hefty upgrade for a floor-mounted heat unit instead of a roof-mounted model. Our floor-mounted heat system is a standard feature, and it contributes to our oven’s superior performance. Having the burner at chest height instead of on top of a hot oven also makes the heat system easier to inspect and maintain.
What type of primary fan and heating chamber is being used?
We frequently use dual-inlet forward curved steel fan wheels of extremely high quality. They retain their shape better and don’t deform under load the way cheaper fans do, so they provide excellent airflow per horsepower. They also move more air than conventional plug fans. We have a special fan shaft that is larger than others on the market. It’s less prone to vibration and more resistant to warping. Instead of economy bearings we use only premium high-temperature bearings rated for sustained service at up to 450°F, or ceramic bearings for even higher heat ratings. The fan drive (motor, pulleys, belts, and bearings) and other major components of our heat system are easy to inspect and maintain from outside of the oven—unlike rooftop systems. Because our heater’s combustion chamber is larger than on most other brands, we move more air (volume in CFM) through the heater, but it moves at a lower speed (velocity in FPM). As a result, more air is directly impacted by the transmission of heat energy from the flame of the burner at any given time. Because our heater’s combustion chamber is symmetrical and the burner’s flame is in the center, we achieve greater transfer and more uniform heating. This subtle design difference makes our equipment more efficient. We also have industry-leading airflow ratings (in terms of the volume of recycled air relative to oven size), so our ovens consistently have excellent convection heating performance and get loads to curing temperatures faster than most other brands. Important: We’ve increased our standard fan sizes and gone to an even more efficient fan design for 2014, so now our ovens have even greater airflow.
What type of internal exhaust airflow pattern is used?
Our exhaust system is usually mounted to the shop floor, typically near the end of the oven that is opposite the heat unit. Since heated air is discharged into the oven from overhead and blows down around the entire perimeter of the oven, hot air is drawn over the contents being heated before exiting the oven. A small amount of oven air is exhausted via one or more flush mounted floor level vents. This airflow pattern significantly shortens the time it takes for the load to reach curing temperatures. Other manufacturers often do something that reduces their manufacturing costs but compromises performance. They mount the exhaust fan on the roof of the oven and/or on the same frame as the heater itself. Not only does this make it tough to inspect and service the exhaust, but the oven wastes fuel because the exhaust draws hot air from the warmest part of the oven before discharging it into the outside atmosphere. Since their heater typically discharges hot air into the oven via plenums mounted on the side walls, the hot air is sucked out as it rises above the object being cured. The problem with this design is that when the object in the oven extends past the side-mounted discharge ducts (front to rear), the exhaust is directing the heated airstream away from at least part of the object. This can lead to longer process times and/or hot and cold spots across the surface of the object. Even on our standard ovens we offer precise adjustment over the oven’s atmosphere via a VFD control system for the exhaust motor(s). The amount of air being exhausted can be fine-tuned while the oven is operational for maximum performance.
What is the turn-down ratio of the oven’s heat unit?
The turn-down ratio indicates the burner’s lowest level of output, and reflects the accuracy with which fuel can be metered to the burner. The higher the ratio, the less waste due to temperature overshoot or “cycling” where the burner cannot adjust properly in response to the temperature controller. Our burner offers extremely fine control of output, with turn-down ratios that are often up to twice as high as other brands. Depending on the product, our turn-down ratio is typically 40:1, one of the best in the oven industry.
What type of gas valve is used? How quickly can it adjust from its highest setting to its lowest setting?
Our equipment uses a high-speed motorized gas valve which quickly responds to the signal from the temperature controller. Depending on the model, our valves adjust across the full operating range in as little as 15-20 seconds. This is much faster than most valves being used. A 120 second full-range response is common in some other oven brands. Simply put, the faster the valve can respond to the information being processed by the temperature controller, the more efficiently the fuel can be metered to the heat unit.
What type of temperature controller is being used?
We use digital PID “fuzzy logic” temperature controllers on our basic panels and PLC devices mated to color touch-screen HMIs on our upgraded panels. These state-of-the-art controls anticipate the performance of the oven and adjust on the fly. Every controller is “trained” on-site to provide optimized performance for a particular oven. Based on the response characteristics of the heater, the controller will accurately anticipate the temperature rise inside the oven and adjust the heat unit’s output very quickly. Unlike ovens with slot-fired burners, there is no seasonal setting or periodic adjustment required. We do suggest that the equipment is inspected regularly and the lens of UV flame sensor checked, but actual cleaning inside the heat system is very rare. Because of the technology we use, the equipment is running at optimal performance settings every time it is operated—not because of crude dampers or venturi adjustments, but because the computerized control system monitors the oven’s performance and adjusts it while the oven is in operation.
What happens if an architectural feature on-site prevents the oven from being installed in the “standard” configuration?
Our modular oven design is the most customizable on the market, so we are often asked to work around on-site features that would discourage most oven manufacturers. We offer our customized ovens at prices that are lower than most companies’ standard catalog models. But, because of their modular design, our standard ovens can often be reconfigured on-site with no additional parts. The heat system and exhaust can be mounted on either side wall or on the rear wall without reworking any of the oven’s components. Because we typically avoid roof-mounted heat and exhaust systems that can only be mounted in one spot, the locations of the floor-mounted heater and exhaust unit are rarely impacted by overhead features—plus both components can be repositioned during assembly with no change in parts. Even on roof-mount models, the location of the exhaust can be changed without the use of additional parts. As an added benefit, the exhaust fan systems are over-built on purpose, so they can easily accommodate the increased resistance of complex ductwork if it is required. There is no need for an upgraded exhaust system or booster fan.
What if the owner wants to relocate or expand an existing oven?
Our modular panel design allows unrivaled flexibility, making it very easy to enlarge our ovens or relocate them after they have been installed. Most customers can increase the size of their oven without significant downtime. We rarely use any field-welded components and our cabin design makes disassembly fast and easy with common tools. Because we use panels that are bolted together instead of mating by tongue and groove or other friction-fit systems, the panels don’t “settle” and are easy to take apart. All of our oven panel flanges, floor track sections, and corner joints include multiple rows of redundant holes on 6” or tighter centers. This assures that if a component is damaged during handling or has to be adjusted while dealing with a problem on-site, a snug fitment can still be obtained without drilling. This feature also enables the installer to overcome bad spots in the floor that won’t allow for a snug fit by a masonry anchor—the installer simply uses one of the adjacent pre-punched holes in the track.
Reliant ovens offer an incredible value in terms of performance, fuel economy, and throughput. Because Reliant’s primary focus is the design and manufacture of superior quality ovens, we are an excellent resource for OEM/PBL partners and end-users alike.