Which of the following drying processes does NOT involve the use of heat?

Allowing the item to drip-dry in a drainer is a method that relies solely on the force of gravity and air circulation to remove moisture from the item. This process occurs at ambient temperatures without the application of additional heat. Drip-drying is especially effective for various items, as it lets natural evaporation occur, allowing moisture to escape into the atmosphere. By not involving heat, this method preserves the integrity of sensitive materials that may degrade or warp under high temperatures.

In contrast, using a heater for drying actively applies thermal energy to expedite moisture removal, while vacuum drying utilizes reduced pressure, often with heat, to encourage evaporation. Blowing off moisture with compressed air also aids in drying without directly introducing heat but typically comes with a cooling effect rather than a traditional drying process.