Abstract: A heat exchange assembly has a heat exchanger, a fan at one side and a drain tray assembly extending beneath the heat exchanger. The heat exchanger has a pipe along which heated or cooled water is supplied, and a stack of vertical, parallel plates between which the fan passes air. The drain tray assembly has a tray with a peripheral wall and a drain outlet at one end. An inverted gutter fits loosely within the tray spaced from its edges by two channels. The height of the gutter is such as to block the space between the upper surface of the tray and the underside of the heat exchanger so as to prevent air flow beneath the heat exchanger.