We’re often asked the question, “what makes your tube heaters (Superior Radiant) better than other brands on the market”? Suffice it to say, of the approximately 15 manufacturers, all are equal in their intent, that is – to heat building space using the infrared tube heating principle. This is accomplished by directing a hot flame down a long 4” diameter steel tube emitter, allowing the tube to heat up, then directing that heat energy to the floor level via continuous parabolic reflectors. This heating method benefits building owners by generating substantial fuel savings and greater levels of comfort compared to forced air systems.
Since infra-red representatives make similar claims regarding what their systems can accomplish for their customers, what, then, separates one infrared manufacturer apart from another? What are their differences? What are the best criteria for selecting one particular brand over another?
As a manufacturers’ representative organization, we make no apologies for claiming that our product is better than the competition. However, we do our best to validate and substantiate our claims by quantitative analysis. We strongly encourage all to investigate other infrared brands and to make an intelligent decision based on their own findings. To aid in this search, we offer the following criteria; five main points commonly discussed among the engineers and contractors who specify infrared tube heating systems. These “specifiers” are particularly concerned that the products they specify will stand the test of time and provide reliable, hassle-free performance. Simply put, they want to avoid potential complaints and costly callbacks and the responsibility of remedying a problem caused by an inferior product they, themselves, have recommended.
Five Criteria for Choosing an Infrared Tube Heater Brand
1) Reflector Design
2) Heat Uniformity
4) Construction quality
5) Local Representation
1) Reflector Design
Almost all tube heater brands utilize a 4” dia. steel tube emitter. A burner on one end forces hot gases through the tubing, emitting infra-red energy around its’ circumference. An optical reflector suspended over the top of the tubes is used to force the infrared (radiant) energy downward. This energy is then absorbed by floors and objects below, which heat up to warm the surrounding air. Superior Radiant offers the only 10-sided deep-dish reflector among all the infra-red manufacturers and that multi-faceted configuration reflects 100% of the infrared energy out and away from the emitter tube down to the floor level. Infrared energy “bounce-back” onto the tube is virtually eliminated and convective heat loss is minimized. More heat to the floor means less heat wasted at the ceiling. And that ultimately means greater fuel savings. By comparison, the poorest reflector configurations are simply a flat top with two sides, which trap heat beneath the reflector and produce more wasted convective heat at the ceiling. Better reflectors have seven or more bends in an effort to get more heat reflected to the floor and do it more effectively. Superior radiant has higher reflective efficiency than competitors.
The Superior reflector also helps eliminate the “hot spot” effect where back radiation of infrared energy creates excessive heat pile-up within the first few feet of the emitter (where the flame is located). The result is: 1) overly intense heat within the first few feet of the system and 2) thermal breakdown of the tube and potential burn through, a common problem with more than a few manufacturers in the industry. By contrast, Superior’s reflector effectively releases the heat more efficiently, with no bounce back or chance of burn through, and heat uniformity is substantially better, which also enhances creature comfort. Needless to say, burner tube replacement is an expensive nuisance for business owners.
2) Heat Uniformity
The ideal infrared tube heater would produce uniform heat temperatures along the entire length of the heater. Of course, simple fluid flow physics says that this is impossible since heat dissipates as it travels downstream (away from the burner). However, Superior utilizes a patented “jet stream” burner, which shoots the flame and hot gases farther downstream and distributes the heat more uniformly than do other brands. By contrast, poor burner designs have a “lazy flame” (where too much flame impinges on the top of the combustion tube, usually in the first 4 feet), causing an uncomfortable hot spot. The Superior burner cup eliminates the “lazy flame” effect. Rudimentary burner theory is to simply introduce primary air at the gas orifice and secondary air around the inside circumference of the radiant tube. With Superior tube heaters, air is introduced at three points – the air plate, the back of the burner cup, and in between a sleeve surrounding the actual burner cup. In addition, the burner cup is positioned off center, near the bottom of the tube emitter, providing additional protection against thermal breakdown at the top of the combustion tube. The resulting benefit is a “column” of air surrounding the flame, producing, in effect, a “jet stream”, and more uniform, comfortable temperatures along the entire length of the emitter tube.
Serviceability is a primary concern with installers and building owners. First, Superior burner controls are easy to access. To service, the contractor simply loosens four screws located on the sides and back of the control box, allowing the hinged cover to hang below it. Controls are viewable and accessible from either side of the box. Since the blower fan feeds air into a compartment separated from the pressure sensing controls, the service technician can make diagnostics while the blower fan is still running. Note: without this capability, the serviceman must close the access door and screw it down tight before determining whether or not the corrective action was, in fact, correct. If not, he must remove the screws to the access door and start the procedure over again.
Second, Superior’s controls are not located in the air stream of the system. Unlike some other brands, which force combustion air through the control compartment, Superior’s controls are isolated out of the air stream. This prevents dust, moisture and contaminants from corroding or adversely affecting circuitry. Superior controls have a 3-year warranty, compared to a 1-year warranty on many competitors.
Third, to aid the contractor while servicing a Superior tube heater, a site glass is conveniently located inside the control box for easy flame visualization. Other manufacturers place the site glass outside the box directly on the combustion tube (where the flame is!) Over time, these site glass micas become clouded with soot and small cracks and require cleaning and eventual replacement. This is yet again another nuisance expense that repairmen and business owners can experience with other infra-red tube heater brands. Superior Radiant has eliminated this problem because the sight glass is located where there is no negative affect from heat.
Fourth, Superior has eliminated the potential for sooting, which occurs when insufficient air is introduced into the air stream, resulting in incomplete burn. Properly orificed and regulated tube heaters should never produce soot. Nevertheless, some tube heater brands suffer from sooting due to 1) poor tolerances to higher elevations (above 4000 ft.) and 2) poor location of the fan blower, inherent in the manufacturers’ control box design. As previously stated, Superior’s fan is separate from the control compartment. Its location allows air to smoothly pass over properly sized air plates directly into the emitter tubing with no air passing through the control compartment. Superior tube heaters have much higher tolerances to elevation, even at some of the highest ski resorts in the country. Nevertheless, all burners are de-rated in-house before shipping out to job sites to ensure optimum performance at elevation.
4) Construction Quality
There is no substitute for seeing a product up close and “kicking the tires”. This especially holds true for the variety of radiant tube heaters in the infrared marketplace. Superior Radiant Products was founded on the principles of product quality and customer commitment. The quality of Superior products is evidenced by superior design, a regard for design detail and an upgrade of materials wherever justifiable. Early on, Superior Radiant Products engineers designed and tooled components by analyzing the weaknesses and strengths of other brands in the industry. Primary components of an infra-red tube heater consist of the burner/control box, emitter tubes, reflectors, couplings and hangers. Let’s compare:
a) Superior’s burner/control box is constructed of heavy-duty powder coated galvanized steel. It uses the most industry-proven name-brand controls. The innovative box design and layout of controls provides easy access, easy servicing and is attractive in appearance.
b) 16 guage steel tubing is the standard in the industry. Superior tubes are heat-treated aluminized. The aluminizing process alone provides corrosion and rust resistance, but its silver color is a poor absorber of heat. Therefore, Superior heat treats the tubes to create a nice gray/black color on the inside and outside of the tubes. This process dramatically increases emissivity (the ability of the tube to emit heat outward) while adding corrosion resistance. Other brands may use non-heat treated aluminized tubing or even hot-rolled steel, which is subject to rust and corrosion. Superior Radiant tube heaters are made to withstand some of the most abusive environments, such as truck and car wash bays and atmospheres with corrosive chemicals.
c) Superior’s reflectors are constructed of 24 guage aluminum sheet metal. The extra bends in the reflector help make it more rigid and less susceptible to warping through the heat-up and cool-down cycles. To help keep the reflectors straight and rigid, Superior provides two reflector support brackets for each 124” long reflector. Superior reflectors stay straight and true and continue to look good over time and use.
d) Superior uses 12” long heavy-duty double band clamps for connecting the 10’ tube sections. They cannot be over-tightened and they make it easy for the installer to get the tubes perfectly straight during installation, a common problem with other brands. This coupling design also makes it easier for just one installer to lift and suspend the tubes in place during installation. Superior couplings are often used for field repairs when other manufacturers’ couplings fail.
e) The entire Superior tube heater is supported by heavy-duty chrome plated hangars, which are generally spaced 9-10 feet apart and suspended from the ceiling with chain. These rugged hangars are designed to carry the weight of the entire system, up to 70 feet in length, and can be positioned horizontally or on a 45 degree angle to direct heat energy where it is best utilized.
The burner, tubes, reflectors and couplings are the main components of an infra-red tube heating system. Superior’s strengths are found in all its’ parts, not just one or two. While other brands may have some good points, we contend that they fall short of meeting all of the criteria specifiers and building owners want.
5) Local Representation
Specifiers look for more than just good products. They want to know that there is a reliable local source for service, parts, warranty, and application assistance – when they need it. Infra-Red Products Supply is the local factory representative, covering all of Utah, Idaho, Western Wyoming, Nevada and other Western States. They keep a plentiful supply of various tube heater sizes and parts in stock to meet the demands of installers and servicemen. They are always on hand to assist in the design and application of Superior tube heating equipment and help ensure that business owners have the best systems in their facilities. Since 1986 Infra-Red Products Supply has developed the core business and organizational skills, coupled with extensive product knowledge and field training, to help ensure customer satisfaction.
A lot of misleading information exists in the heating industry regarding the term efficiency. What does the term efficiency mean? In the context of space heating, there are basically four types:
1) Thermal Efficiency
2) Combustion Efficiency
3) Radiant Efficiency
4) Reflective Efficiency
Thermal efficiency is a general term used in the gas heating industry to describe the ability of an appliance to convert fuel to thermal energy (heat). Combustion efficiency is a more specific term used to describe the combustion process of a burner and the ability of the heat exchanger to squeeze out heat what would otherwise be lost through a flue to the outside.
It is important here to recognize that efficiency ratings applied to home furnaces are not applicable to infrared tube heating systems. That is because infrared systems rely on radiant (infrared) energy as the primary method of heat transfer, not convection. Given that fact, no standard for determining the efficiency of an infrared tube heater has ever been established by CSA that is agreeable among all the infrared manufacturers. Infrared manufacturers are left to use their own criteria and devices for determining the effectiveness of their systems based on fundamental principles of thermal dynamics.
Thermal efficiency is important. Converting fuel to useable heat is the goal of all heating appliances. But infrared tube heaters rely mostly on the latter two terms, radiant efficiency and reflective efficiency. Radiant efficiency is the ability to convert thermal energy (heat) to radiant energy. In a tube-type heating system, hot gases are forced through a 4” diameter steel tube. The goal is to heat the tube to a temperature of about 1000 degrees F. The ability of the tube to emit the stored heat, its emissivity, is largely a function of the properties of the tube itself. Following are emissivity ratings for various materials measured on a scale of 0 to 1.
Material Emissivity Index Emitter Temperature
Plain steel 0.79 to 0.81 1000 Deg. F
Aluminized Steel (type 1) 0.21 to 0.50 1000 Deg. F
Aluminized Steel Heat Treated 0.80 1000 Deg. F
Cast Iron 0.95 1000 Deg. F
Stainless Steel (Type 304) 0.44 to o.62 1000 Deg. F
Galvanized Steel 0.28 100 Deg. F
Colonized Steel 0.57 1000 Deg. F
Aluminum 0.02 to 0.05 100 Deg. F
Stainless Steel (Type 430 polished) 0.10 to 0.20 100 Deg. F
Pyromark Paint (silicon resin) 0.80 1000 Deg. F
This index shows that some of the lowest emissivity ratings are found in stainless steel and aluminum. Some of the highest are found in cast iron, heat treated steel and specially coated steel. Generally, the darker “black body” colored steel (such as heat-treated aluminized) achieves a higher emissivity rating compared to silver or lighter colored steel.
Also important is reflective efficiency, which, in the context of infra-red tube heaters, simply refers to the ability of the parabolic reflector to reflect or bounce the highest percentage of infra-red energy from the emitter tube to the floor level. Superior Radiant tube heaters combine the use of heat treated aluminized steel (for high emissivity and rust prevention) along with virtually 100% radiant efficient deep dish parabolic reflectors – the best in the industry!
Scott Workman is owner and president of Infra-Red Products Supply, Inc. of Draper, Utah and a leading expert in gas radiant heating systems. For more information, please feel at ease to call us 801-571-0036.