Definition of Room Temperature

To the average person, "room temperature" is the thermometer reading of the room. In science and industry, the temperature is defined. However, not everyone uses the same value:

Room temperature is a range of temperatures that denote comfortable habitation for humans. Over this temperature range, a person isn't either hot or cold when wearing ordinary clothing. The definition of the temperature range is somewhat different for science and engineering compared with climate control. For climate control, the range is also different depending on whether it's summer or winter.
In science, 300 K can also be used as room temperature for easy calculations when using absolute temperature. Other common values are 298 K (25°C or 77 °F) and 293 K (20°C or 68 °F).

For climate control, a typical room temperature range is anywhere from 15 °C (59 °F) and 25 °C (77 °F). People tend to accept a slightly higher room temperature in the summer and lower value in the winter, based on the clothing they would wear outdoors.

Ambient temperature refers to the temperature of the surroundings. This may or may not be a comfortable room temperature.