30 years ago an all-electric car would only be commonplace as a subject in a Popular Mechanics article, and highly unlikely to pass you out on the interstate. Today more than 20 million electric vehicles traverse the streets around the globe and the trend is expected to continue rising. Electricity has paved the way for many things throughout history and forges new possibilities daily.
What are electric boilers? Electric boilers are simply pressurized vessels containing fluid (usually water) that is heated to its saturation temperature to create steam or in some cases hot water. Steam is used for various commercial and industrial applications around the globe. Electric boilers rely on resistance elements that are affixed inside the boiler to heat the water and create steam or domestic hot water.
Boilers like cars have long depended on the combustion of fossil fuels to create the steam or hot water needed for various applications. With the increasing attention being focused on green initiatives and reducing our carbon footprint, electricity is being seen as an alternative fuel source for creating this critical steam energy.
Let’s be perfectly clear before we continue, commercial and industrial electric boilers require some serious electrical power. Power that comes from a power plant. Power plants that utilize larger capacity package boilers providing steam to turbines and generating electricity. Packaged boilers that require a fuel source. The point being, that there is still an upstream need for the combustion of a fuel source.
Electric boilers are not a newfound idea. Electric boilers for homes are very common for providing smaller capacities for steam and hot water. The use of electricity to heat water has roots back in the early 1900s. The industrial revolution had man racing to innovate new ways for many things, and many machines were engineered to meet these innovations. Many businesses and manufacturers utilize electric boilers for various process and application needs. It’s common to see where businesses will use rental electric boilers to supplement when an increase in production is necessary.
Why would a company use an electric boiler? Businesses rely on steam for many things. An electric boiler offers many advantages to conventional gas or oil-fired system. Firstly, electric boilers rely on electricity, therefore there is no need for additional field piping or oil tanks. Now being there is no combustion occurring this eliminates emissions. This can be especially useful when permitting may be a concern.
There may be times when permits are required by jurisdictions to operate a gas or oil-fired system because of stack gases. Electric boilers eliminate this need and may speed up the process sometimes required for permitting the use of a steam boiler. Different boiler capacities and sizes can require different operating requirements and permitting. When using an electric boiler, however, the emission regulations or permits are not applicable.
Some companies take advantage of major green initiatives within their local, state, and federal governments by using electric boilers. Certain tax breaks are available for reducing an organization’s carbon footprints. Not using fossil fuel for steam production may very well qualify a company and can offset the cost of purchasing an electric boiler.
This lack of combustion can also make the use of an electric boiler an ideal solution when contingency steam is needed. A mobile electric boiler can be used to supplement steam production and is sometimes placed in areas where an oil-fired boiler cannot operate. With a generally smaller footprint, no fuel piping, and no stack installation, temporary electric boilers are often placed right inside a mechanical room or on a loading dock.
Other times an electric boiler is a great solution for a business could be when noise is a factor. Hospitals, schools and universities, resorts and hotels, and government buildings often utilize electric boilers to eliminate excessive noise in or around a facility.
How do electric boilers work? As noted, electric boilers use resistance elements, much like what you could find in a water heater. The vessel is filled with many elements to rapidly increase the water temperature and vessel pressure. It does this with either a step controller, PLC or other customizable control much like the Siemens LOGO.
As the unit calls for heat, a pressure switch closes and energizes contactors. The associated programmer allows the energizing of the elements as necessary to meet and maintain the needed pressure or temperature. The use of sophisticated controls allows the electric boiler to operate much like a full modulation system.
Some electric boilers have a pre-heat option. This is comparable to the low-fire hold switch on a firetube boiler. This pre-heat switch allows for the boiler’s water to be raised to a warmer temperature before the controller takes over. This can reduce energy cost and premature wear on the boiler or elements or other components. Facilities that shut down their electric boiler every evening could find this controller very useful.
How are electric boilers sized? Electric boilers are sized a bit differently than gas or oil-fired boiler. Kilowatts are used to describe an electric boiler’s size. The roughly ten rule, as I refer to it, is a good practice for quickly converting the size of an electric boiler into horsepower. 9.8 kilowatt is equivalent to a single boiler horsepower. So for example:
This rule of thumb can help you determine how much energy is required to operate an electric boiler. Other factors could be necessary to determine total operation requirements like feed pumps, water softeners, or other controls and support equipment.
Electric boilers are common in many facilities where emissions, noise, or space are concerns. If your facility is interested in learning more about electric boilers or needs a rental electric boiler contact Power Mechanical Inc. today. We have a large fleet of emergency rental boilers in a wide range of pressures and capacities sure to meet your facility’s contingency steam needs.