Heat transferred from a heating wall with a heat transfer coefficient of approximately 0,45 W/m2K for a room with a temperature of +20°C (at outdoor temperature te = -15°C), Marks: L – spacing of heating pipes with a diameter of 1/2”, 1 – Insulation (8 cm of mineral wool), 2 – solid brick wall (with a thickness 36 Cm).

The figure shows graphs illustrating the problems related to the use of vertical and horizontal heating planes in the given temperature conditions. For a wall made of solid brick 0,36 m, depending on the spacing of steel heating cables and the average water temperature, the specific heat output ranges from approx 45 W / m2 to over 400 W/m2. At average heating water temperatures of + 50 + 60 ° C and different pipe spacing, the temperature of the internal surface of the partition varies from + 28 ° C to + 46 ° C. The data shown in the drawing may be characteristic of steel heating pipes placed in the ceilings.

The heat is transferred by steel heating pipes placed in the ceiling with a heat transfer coefficient equal to 1,5 W / m2K and separating rooms with temperatures of + 20 ° C. Marks: L – spacing of heating pipes with a diameter of 1/2” (the heat given off at the edges of the ceiling and transferred to the room above was omitted)

They concern steel pipes built into the concrete layer of the ceiling, with the share of the heating area in the total area of ​​approx 50%. The amount of heat obtained with similar spacing of heating pipes is smaller than for heating walls.

For heating ceilings, the same rule applies as for internal walls; the smaller the spacing of the heating pipes and the greater the average temperature of the water flowing through them, the greater the amount of heat transferred to the heated room. They grow with an increase in the share of the heating surface, the increase is proportional to this area. The amounts of heat indicated above also include the amounts of heat given off by the floor. Should be added, that the floor in the room above also gives off heat.