The heat sink covered with black heat-resistant paint allows the recovery of heat from the exhaust gas. Thanks to the ribbing used, the heating efficiency has been increased. The exhaust pipe is used to build chimney connections (flue). The chimney connection system can be used as a connection to fumes discharging boilers, the temperature of which can briefly reach 1000 C. Recommended for fumes from the fireplace and solid fuel heating devices operating without condensation.