Thermal conductivity of the material.
Tile has higher thermal conductivity than carpet.
It simply has a higher conductivity and density and thus removes more heat from your relatively warm body more rapidly.
So it makes sense that the specific heat of the carpet is lower meaning it will heat up really fast when you step on it making it feel warmer than the tile which has a higher specific heat meaning it takes longer for it to warm up when you step on it and therefor feels cold.
For example wool carpet rates a maximum r value of 2 1 while other types of carpet can rate as low.
However because marble tiles are usually twice as thick as ceramic tiles they offer greater protection against thermal conductivity.
As can be seen from the table the thermal resistance of carpet is significantly higher than that of concrete and plywood two common flooring materials and similar to fiberglass insulation.
Wool carpet had a higher insulation value than com parable carpets of other fibre types.
Heat conductivity is all about the rate at which the material can conduct heat.
The thermal conductivity normally found in tables is the value valid for normal room temperature.
Tile and stone also retain heat well making the system efficient.
Wool carpet had a higher insulation value than comparable carpets of other fibre types.
Tile and rocks have a higher thermal conductivity than carpet and fabrics so they can transfer heat away from a foot at a much quicker rate making the tile appear cool to the touch.
When high temperatures are involved in ovens for instance the influence of temperature has to be taken into account.
Tile and stone have a high thermal conductivity meaning that the heat from an underfloor heating pipe or wire transfers to the floor surface quickly.
Pvc tile has only 1 3 of the insulation of wool carpet.
Carpet ranks very highly i e.
Carpet particularly wool and shag varieties provides the best r values among all standard flooring choices.
Of carpet with its millions of tiny fibres traps air and further increases its thermal insulation.
The thermal insulation values r values of different household materials are compared in figure 1.
Thus any statement that tile is one of the coldest floor materials is quite simply a misconception.
Simply put tile is the better conductor of heat than wood or carpet and can take away the heat from your feet faster than the others.
Pvc tile has only 1 3 of the insulation of wool carpet.
This value will not differ much between 273 and 343 k 0 70 c.
Thermal conductivity explains why walking bare foot on a cold tile floor feels much cooler than walking on carpet even though both are at room temperature.
The best type of flooring to use with underfloor heating is tile and stone.