In some embodiments, preferences 135 are specific information about a user such as height, weight, sex, activity level, or insulation value of clothing. The system then may use an estimator 150 which uses at least one of the preferences associated with the known user to estimate at least one of user metabolic rate, user heat level, user convection level, or user sweat level, etc.

In some embodiments, there is also a radiant value calculator 165 that is used to calculate radiant temperature for a given person or people. This may be associated with the comfort level calculator 155. The comfort level calculator calculates (in some embodiments) a comfort level, which will be used by the modifier 140 to modify state of the defined space 105. This may be associated with the person or object identified by personal electronic device or may be calculated for a generalized person. Humans do not directly determine from a specific temperature how comfortable they are. Rather, perceived human comfort is a combination of air flow, humidity, and radiant temperature, which, roughly, is the mean temperature of a set of surfaces around a person. According to Wikipedia¹, ¹ https://en.wikipedia.org/wiki/Mean_radiant_temperature, last viewed May 12, 2020

• • “There are different ways to estimate the mean radiant temperature, either applying its definition and using equations to calculate it, or measuring it with particular thermometers or sensors.