Coil heaters and cable heaters are heating elements formed from straight, uncoiled segments of heating cable. Forming straight cables into patterns increases the surface area and heat transfer capability, but also requires increased energy and watt density. Most coil heaters and cable heaters operate on AC voltages. Some include a grounding wire or provide distributed wattage arrangements to concentrate heat distribution. Coil heaters and cable heaters can be configured with different termination options. For example, electrical connections can be made via a plug configuration and protected by a terminal box interface. Armor cable, metal braids, and flexible conduits are used to protect insulated leads.
There are a variety of shapes and sizes for coil heaters and cable heaters. Some devices are straight, square, or rectangular. Others are round, coiled, spiral wound, or star wound. Spiral wound heaters are used to generate high temperatures in restricted areas. Star wound cables are offset coils inserted into pipes or ducts to create a turbulent flow in air or fluid. In terms of measurements, coil heaters and cable heaters vary according to coil inner diameter, outer diameter, length, and width. Some devices encase the coil or cable to protect it from damage and to maximize heat transfer. In other devices, the coil or cable includes an internal temperature detector such as a thermocouple.
Coil heaters and cable heaters are made from several different types of materials and typically include insulation. Sleeve, sheath, and jacket materials include aluminum, brass, copper, iron, nickel alloy, steel, and stainless steel. Insulation materials include ceramics, mica, minerals, and fiberglass. Mica is highly resistant to acids while fiberglass is impervious to many caustics. Some coil heaters and cable heaters may be fully or partially immersed in heated substances, while others are corrosion-resistant or suitable for cryogenic use. Clamping straps provide additional protection for coils and connections.
There are many applications for coil heaters and cable heaters. For example, larger devices are used in plastic injection molding machines, holding tanks, metallurgical analyzers, and pulp and paper processing. Coil heaters and cable heaters are also used in blow molding machines, oil reclamation equipment, and food and candy extruders. Smaller, localized devices are used in labeling, bag sealing, hot stamping, and packaging equipment.
Source : http://www.globalspec.com/LearnMore/Processing_Equipment/Industrial_Heaters/Cable_Coil_Heaters
About Coil Heaters and Cable Heaters
How to Choose a New Water Heater
Tankless water heaters are catching on in the United States as an alternative to storage tank models. Instead of constantly heating water in a stored tank, tankless units only heat water as you need it. Turning on your hot water triggers an electric or gas-powered heat exchanger that quickly heats the water to your preset temperature. There are point-of-use models that only operate one or two fixtures, or whole-house units that take care of all your water heating needs. Point-of-use models are small and can be mounted under a cabinet or in a closet. Whole-house units are also wall mounted, saving valuable floor space. To get more detail about how they operate and how to size them to fit your needs
There are many benefits to going with a tankless heater. Most units come with a federal tax rebate of $300 and are more efficient than storage tank models -- you can shave as much as 20 percent from your water heating bill [source: Energy Star]. Since tankless heaters heat water as it flows, you'll never run out of hot water. Tankless heaters also last five to ten years longer than a storage tank model. Electric models don't produce greenhouse gases, and there's no possibility of flooding due to a ruptured tank.
There are also drawbacks to tankless heaters. Natural gas whole-house units can cost up to three times as much as conventional heaters. Although you'll have an unlimited supply of hot water, there are limits on volume because the output is split between all of your fixtures. Some houses require a larger natural gas line to supply the unit with enough fuel, adding to the price. Further expense comes from venting the gas or propane with pricey stainless steel tubing. If you go with an electric unit, it may require an additional power circuit. Gas powered models produce greenhouse gases and require annual servicing. The time that it takes to get the hot water from the heater to your faucet can increase water waste.
A large whole house electric model costs $500 to $700, about the same as a similar storage tank unit. Gas models have a much larger price difference. A whole house gas tankless heater can cost as much as $2,000. The storage tank counterpart runs about $450. Installation of tankless heaters is almost always more expensive as well.
To decide which type of heater to go with, add up the total price of purchase and installation for the heaters that fit your needs. Then compare that to the efficiency rating you'll find on the yellow Energy Star sticker on the heater. The amount of time it takes to recoup the additional expense of a tankless heater is called the payback period. You should also consider that a storage tank heater will need to be replaced again in about 10 years -- you'll get roughly 15-20 years of use from your tankless model.
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How to Choose a New Water Heater (2)
It's the dead of winter, freezing cold outside, and you seek comfort in the piping hot confines of your morning shower. With the lights dimmed, the water hits your face and rolls over your shoulders. Your muscles relax one by one as the warmness of the water finds its way down your legs to your chilly, restless feet. Lathered with soap and shampoo, you slump against the warming tile, eyes closed. You consider falling back asleep standing fully upright when it happens -- a sudden burst of ice cold water hits your chest like acid rain. You crank the cold water down to zero with no result. The water temperature has turned against you, refusing heat in a stubborn show of determination. The cruel reality hits you -- your water heater has just bought the farm.
A visit to your local big-box home-improvement store is overwhelming, to say the least. You're faced with too many brands and too many sizes to choose from. Different fuel sources and energy ratings confuse you. And what's the deal with these heaters that don't even have a tank? How on earth can they meet your needs? Unfortunately, your big-box home-improvement employee helps you none -- you're going to have to figure this one out on your own.
Fear not, consumer -- your trusted friends at HowStuffWorks are here for you. In this article, we'll walk you through everything you need to know about purchasing a new water heater. From gas to electric, tankless to conventional, we'll lay it out for you in simple terms so you can live to shower again.
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Hybrid Water Heater Technology
Basically, hybrid water heaters combine the technology of tank and tankless conventional hot water heaters.
Traditional tank heaters heat from the bottom, with the air rising through the tank and exiting from the top, allowing a fair amount of heat to be wasted. Tankless models also heat from the bottom, but the water flows through copper pipes. However, tankless models have been criticized because they don't store water and continually provide hot water to multiple places in your home.
The technology behind new hybrid water heaters varies by the model. Eternal Hybrid, one of the few currently out on the market, uses multiple passes of the heat and water to warm up more efficiently. The machine has 44 pipes that heat up, and the water flows around them for quick heating [source: Eternal Water Heater]. And, unlike a tankless system, the hybrid heater contains a reservoir to hold some water at all times, so you never run out of hot water.
This isn't the only technology that hybrid water heaters can use. General Electric is planning a hybrid electric water heater to hit the market at the end of 2009 -- it uses hybrid technology to absorb heat within the air and then transfer it to the water [source: GE]. Hybrid WaterHeater Incorporated is developing a heater for 2011 that will amalgamate several technologies, including fuel cells, batteries and super capacitors [source: Hybrid WaterHeater Inc].
To discover the benefits of a hybrid water heater over what you're using now, read on.
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How Hybrid Water Heaters Will Work
Unless you've had the unfortunate incidence of a broken water heater, you probably haven't given much thought to that large structure in the closet or basement. Until it stops working and you're stuck with cold showers, water heaters don't occupy most people's daily thoughts.
In fact, until recently, water heaters weren't even on the radar of Energy Star, a government program that certifies energy-efficient appliances. Even though water heaters generally use the most energy of any home appliance, Energy Star didn't start regulating their energy usage until 2008 [source: Green].
Now there's a movement to make water heaters more energy efficient. This can mean huge energy savings, as about 17 percent of a home's energy usage stems from its water heater [source: Green]. These savings are good not only for the environment and your future, but also your wallet. It's estimated that hybrid water heaters could save the average family hundreds -- possibly even thousands -- in energy costs each year.
Sound like a dream? Well, on one hand, it is. There are only a few hybrid water heaters on the market, but there are several more in the pipeline for the next couple of years. And hybrid heaters are more expensive than your average water heater - about $2,000 to $3,000 a pop for the ones on the market righ t now. This article will help you get a jump on the latest developments in hybrid water heater technology, so when a model that meets your needs hits the stores, you'll be ready to buy.
When you hear the word "hybrid," you might imagine a tank that gets charged with a battery and then can also run off gas, like a hybrid car. Read on to discover the technology behind hybrid water heaters and find out if your imagination is correct.
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How Infrared Heaters Work
You probably learned about infrared light when you studied wavelengths in science class . You also might have heard of infrared radiation or infrared technology, just from casual tidbits on TV commercials or in magazines. But to be honest, you've either forgotten or never really understood the science behind wavelengths and light spectrums. So you pretty much draw a blank when you try to figure out what infrared heaters do.
You might remember that infrared light isn't visible because it's beyond the spectrum we can see. That's the gist of an infrared heater: The heat is a product of light that is invisible to our eyes. The reason we get warm from an infrared heater is because our skin and clothes absorb the light [source: Wasch]. It's like the difference between being directly in the sunlight versus sitting in the shade. You feel warm in the sun because the light that hits your clothes and skin keeps you warm, but when you're in the shade, the light doesn't reach you as well.
There are several kinds of infrared heaters. Some might direct their infrared light straight into a room or space to create heat on the object it reaches. Other infrared heaters contain three parts that create heat: infrared light bulbs, a heat exchanger (such as a good metal conductor like copper) and a fan that blows air onto the exchanger to create the heat [source: Wasch].
Infrared heaters also differ in fuel source and c onstruction material. There are propane, natural gas and electric heaters. Some are ceramic, and there are also portable ones [source: IQS Directory].
Infrared heaters have certain specifications and should be used only in certain situations. These heaters may be more environmentally friendly. Click to the next page to read more about some of the specifications of infrared heaters.
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