METHOD OF DETERMINING RESISTANCE TO HEAT TRANSFER OF BUILDING WALL BURIED IN SOIL Russian patent published in 2025 - IPC G01N25/18 

FIELD: construction; measuring.

SUBSTANCE: invention relates to construction physics, namely to obtaining characteristics of heat transfer resistance of walls of buildings buried in soil in natural conditions. Method of determining resistance to heat transfer of a wall of a building buried in the ground, including measurement of temperature values outside and inside the building, on its walls, as well as surface density of heat flow. On the inner surface of the wall buried in the ground, U-shaped boxes with heat-insulated inner walls are evenly distributed along the height of the walls at distance of 1 metre, and in each of the boxes a heater, air temperature sensors, a temperature sensor of the inner surface of the wall and a sensor of surface heat flow density are placed, and the boxes themselves are sealed from the wall of the building. At the junction of the wall and floor of the building, an L-shaped box with heat-insulated inner walls is installed, a heater is placed in it, air temperature sensors, wall inner surface temperature sensor and heat flow surface density sensor, and the box itself is sealed from the building wall and floor. On the outer surface of the U-shaped boxes and the L-shaped box, air temperature sensors are placed inside the room, and an outside air temperature sensor is installed on the outer surface of the wall. Inside the U-shaped and L-shaped boxes, heaters are switched on to maintain air temperature inside them, which is equal to the air temperature inside the room, then sensors installed outside and inside the boxes, as well as on the outer surface of the wall are switched on and recording of their readings is started. According to the measured readings of the above sensors during the winter period with a measurement interval of 1 hour, the experimental heat transfer resistance of the wall buried into the ground is determined by formula where t_o is outside air temperature, °C; t_i.s. is the temperature of the inner surface of the wall buried in the ground, °C; q is surface density of heat flow, W/m²; α_o is coefficient of heat transfer between outside air and outer surface of wall, 23 W/(m⋅°C); R_exp is experimental resistance to heat transfer, m²/(W⋅°C). Obtained array of values is then broken down into five-day subarrays, on the interval of which the average resistance to heat transfer of the wall buried into the ground is determined, wherein the five-day intervals on which this average value is determined begin from each day of the winter period. From the values obtained as a result of such processing, the minimum value of the average resistance to heat transfer of the wall buried into the ground is selected, which is taken as the result of the experiment.

EFFECT: high accuracy of the obtained characteristics of resistance to heat transfer of walls of buildings buried in the ground.

1 cl, 3 dwg