In this paper

we′ve established the heat balance equation of the building envelope

calculated the floor surface temperature

heat flow rate per unit floor area

indoor air temperature and inner surface temperatures of building envelopes.Through the comparison of thermodynamic properties with those of traditional column radiators and experimental data fitting

it provides the calculation formula of the heat release with an applying range of the temperature water supplies is 30~60℃ and water flow rate is 0.030.60 cubic metre per hour

verifying validity of the formula.