Multiple terminologies as “radiant heating”, “radiant heater”, “infrared heater” and most of all the lack of regulations about what an infrared heater is, creates confusion. Indeed, a heater that “generates” only 10% of infrared (so 90% convection heating) can be designated “infrared heater” if the manufacturer decides so, primarily for marketing reasons.
The answer to the question is (as often) multiple. Yes the feeling of warmth will fade almost immediately when speaking of average or even poor quality heaters. In this industry, only high-end products are able to produce enough infrared and at a sufficient range so that the energy accumulates in a “significant” way into the walls. Indeed, when the infrared heat builds up in the walls of the housing, it naturally heats up “as a whole” and in a homogeneous way, providing an excellent comfort. In addition the infrared is an excellent way to increase the apparent air temperature without increasing the ambient temperature (thus the consumption): see our article.
A temperature (almost) uniform from the floor to the ceiling (unlike convectors) is a key to comfort.
“If the heater has a sufficient power and the range of its radiation is at least 4 m and the heater is well placed within the room (to reach all areas), then, even with the heater being switched off, the heat stored in the structure will be redistributed in the room.“
Source manufacturer: DEGXEL
Only infrared heaters with a radiation range over 50% (so 50% of remaining convection) are able to produce enough infrared at sufficient range (distance). Of course the heater placement is a key element to the effectiveness of this contactless heating technology. It does not heat the air directly but indirectly after having heated the walls, floor and ceiling. If the heater is placed in an isolated area of the room, or if the radiation is blocked by a furniture for instance, it is easily understood that the radiation won’t accumulate in the whole structure of the room. In that case, the comfort is no more guaranteed.