Radiant Air Floor Heating
Air-heated radiant floors can be used in conjunction with solar air solutions,
but even in this case the system is disadvantageous.
Radiant air floor heating is not a popular radiant heating choice for one reason: It's just not that efficient, as air can't stay hot for very long. Another reason for its unpopularity is that this system relies on solar energy, which is not always available, particularly at night.
According to the US Department of Energy - Energy Efficiency and Renewable Energy (EERE), solar air heating systems use air as the working fluid for absorbing and transferring solar energy. Solar air collectors (devices to heat air using solar energy) can directly heat individual rooms or can potentially preheat the air passing into a heat recovery ventilator or through the air coil of an air-source heat pump.
Air collectors produce heat earlier and later in the day than liquid systems, so they mayproduce more usable energy over a heating season than a liquid system of the same size. Also, unlike liquid systems, air systems do not freeze, and minor leaks in the collector or distribution ducts do not cause significant problems, although they do detract from performance. Still, air is a less efficient heat transfer medium than liquid, so solar air collectors operate at a lower efficiency than solar liquid collectors. So while air floor heating is an option for residential homes, its disadvantages may outweigh the benefits.
Read more about solar room air heaters and what role they play in air floor heating.