Patent ID: 8544460

Claim:
A ground-heating apparatus, comprising: a frame configured to sit or be placed on the ground; a heat exchanger disposed in the frame, the heat exchanger configured to emit heat energy, the heat exchanger further comprising: a first tube comprising first and second ends, the first end configured to releasably couple to the heater assembly, the second end operatively coupled to a first elbow, a second tube comprising third and fourth ends, the third end operatively coupled to the first elbow thereby defining communication from the first tube to the second tube, the fourth end terminating near the first end, the fourth end configured to be closed, and a third tube having fifth and sixth ends, the third tube disposed within the second tube thereby defining communication from the second tube to the third tube, the fifth end disposed near the fourth end, the sixth end configured to exit from the heat exchanger; and a heater assembly, the heater assembly operatively coupled to the heat exchanger, the heater assembly configured to convey heated air or gas through the heat exchanger.