In most cases, Power Density is used to describe the exposure to radio frequency (RF) energy. Power density decreases at a rate inversely proportional to the square of the distance (1/r²) to the radiating source. Limits to the power density are set by the regulatory entities of each country or region and are usually in the order of 1 mW/cm².
The Smart Thermostat communicates via 6LoWPAN, which is a low power standard for IPv6 enabled devices and reaches a power density of approximately 0.0003 mW/cm² at one-meter distance during transmission. The Smart AC Control uses Wi-Fi for networking and reaches a power density of approximately 0.0005 mW/cm² at one-meter distance during transmission.
One also has to keep in mind that during normal operation the devices are transmitting on a very low duty cycle in order to save energy, which reduces exposure to RF energy even further.
When comparing the average sending Power Density of tado° devices (about 0.004 mW/cm²) with that of a Wi-Fi enabled device such as a laptop or smartphone (about 0.1 W/m²) it becomes readily apparent that the Power Density of tado° devices is magnitudes lower.
In addition to this, tado° devices transmit much less frequently and are operated at least at “arm’s length”, in contrast to smartphones which are often operated directly next to the head.
Together these facts result in an extremely low overall RF exposure from tado° products compared to many common household electronics.