Abstract: A heat exchanger apparatus for a portable tank that has an access opening and an access door removably attachable to seal the access opening. The apparatus includes a cover plate configured to be removably attached to the access opening to seal the access opening, and a heating circuit attached to an inner surface of the cover plate such that when the cover plate is attached to the access opening, the heating circuit extends into an interior of the tank. Input and output ports extend through the cover plate and are connected at inner ends thereof to the heating circuit such that fluid flowing into the input port flows through the heating circuit to the output port. The input and output ports are adapted at outer ends thereof for attachment to a fluid heating system to circulate heating fluid through the heating circuit.

Abstract: A heat transfer system having a flexible surface member having a first side and a second side, forming a heat transfer surface, and two or more thermal conduits, spaced apart and extending across a portion of the heat transfer surface, the two or more thermal conduits adapted to receive a thermal media to form a heat source (heating) or heat sink (cooling) across the heat transfer surface. The flexible surface member may have a plurality of edge regions, the two or more thermal conduits extending between edge regions, such as adjacent edge regions or opposing edge regions. The flexible surface member may have a plurality of corner regions, the two or more thermal conduits extending between corner regions, such as adjacent corner regions or opposing corner regions.

Abstract: A heat transfer system with a surface member having a first surface and a second surface, forming a heat transfer surface, and a thermal conduit attached to and spaced across the first surface, the thermal conduit adapted to receive a thermal media to heat or cool the heat transfer surface to heat or cool a body within the heat transfer surface. A method of heating or cooling a body including providing a heat transfer system comprising a surface member having a first surface and a second surface, forming a heat transfer surface, and a thermal conduit attached to and spaced across the first surface, the thermal conduit adapted to receive a thermal media to heat or cool the heat transfer surface, positioning the heat transfer system proximate the body, and supplying heated or cooled thermal media to the heat transfer system to heat or cool the body.