An uninsulated heating element composed of flat stripes is referred to as what type of heating element?

An uninsulated heating element made up of flat stripes is referred to as an open ribbon heating element. This type of element provides efficient heating because the flat ribbons can have a large surface area exposed to the air, which enhances heat transfer. The open design allows for quick heating and effective heat dispersion, making it suitable for various applications in heating systems.

The other types of heating elements mentioned serve different functions. Flat coils generally involve a different configuration that may not provide the same exposure to the surrounding air. Spiral wire heating elements are wound in a spiral shape, which affects how heat is distributed. Electric strips, while they can refer to similar heating elements, do not specifically describe the uninsulated characteristic that is key to identifying open ribbon heating elements.