Tutorial: Build an Industrial Heater Sizing Calculator Using HTML, CSS, and JavaScript

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A DEV Community tutorial walks developers through building a browser-based industrial electric heater sizing calculator using HTML, CSS, and JavaScript. The tool estimates the electrical power needed to heat a given volume of water from an initial to a target temperature within a set time. It applies the standard heat energy formula Q = m × c × ΔT, converting the result to kilowatts by dividing energy by time in seconds. Users can also apply a safety factor of up to 25 percent to account for real-world heat losses through pipes, tanks, and the surrounding environment. The project is structured across three files and is designed to be responsive and accessible, including support for screen readers via the aria-live attribute.

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