Minimum heating temperature
The lowest air temperature that a heat gun can produce when operating in normal mode, in other words, the lower limit of the operating temperature range. Accordingly, the lower this limit, the wider the range, ceteris paribus, and the more versatile the tool: after all, for different jobs and temperatures, you need different ones. Some modern hair dryers have the ability to "cold" blowing, without heating.
Max. heating temperature
The highest outlet air temperature that a hair dryer can provide. As with the minimum temperature, this parameter determines how wide the operating range of the tool is and for what range of work it can be used. High operating temperatures are important not only for refractory materials — they can significantly speed up the processing of large surfaces. On the other hand, it is worth considering that for strong heating, appropriate power is required, which affects the weight, energy consumption, and often the price of the hair dryer.
Weight
The total weight of the tool. On the one hand, heat guns are held in the hands during operation, which means that a lot of weight is undesirable for them — heavy devices are less “agile” and tyre the operator more. On the other hand, too little weight can mean low quality materials, a small thickness of insulation and, accordingly, unsatisfactory safety performance. Therefore, in most modern models, the weight is at least 500 g, and in the most advanced models it can exceed 1 kg. Also note that some "heavy" hair dryers may have a design that allows you to install them on a flat surface during operation.
If there are additional nozzles in the kit, the weight of the tool without them is usually indicated.