Abstract: The present invention relates to a seat or chair cooling apparatus. In an embodiment the seat cooling apparatus cools the back of a user without the need of forced air. The seat cooling apparatus includes an array of conduits held in place by a set of supports to form a heat exchanger. Heat from the contact surfaces is removed by free convection, an upward air movement due to density difference. When the seat cooling apparatus is in the preferred substantially vertical arrangement, the warm air exiting the conduits is replaced by cooler air entering the conduits. A seat securing attachment secures the heat exchanger components to a seat. The seat cooling apparatus shapes into the back of the user to provide comfort that is effective in cooling. The seat cooling apparatus can be light weight, portable, and occupies little space, can be quickly installed and removed, easily cleaned and is very low cost to manufacture.