What's the heating range of a patio heater?

To determine the heat range, a patio heater is tested in an enclosed space of 18°C where the wind has no influence. During this kind of test, sensors in the floor measure at which maximum distance the heat can still be felt. For example, you have a heater with a range of 15m². This doesn't mean the heater feels just as warm at a distance of 10m² as it does at 15m². You can still feel the heat, but not as much. That is why you shouldn't take the heating range too literally. In the image, you can clearly see that the heat intensity of the light decreases a little bit at a time.

Heaters are tested in an ideal situation of 18°C where the wind has no influence. In reality, this isn't a very common situation. Perhaps your heater is mounted in a windy, open space where the outdoor temperature is 14°C. In that case, a heating range of 15m² as measured in the test situation is unrealistic. In the image, you can see that even in the first arc, there is already less thermal radiation than in the ideal situation due to wind and a lower temperature.

The images above show the heat radiation of a round heater. But there are also other models, of course. Think of a hanging, rectangular heater whereby the heat isn't spread around the heater. The image on the side shows what the thermal radiation looks like in this case.