A room heating and/or cooling device which includes a housing which can be mounted on a ceiling, at least one heat exchanger being located in the housing and having an inlet connection whereby heating water or cooling water can be circulated through the heat exchanger. A room light fitting, such as a fluorescent fitting, is mounted directly below the housing and a fan is provided to draw air through the chamber over the heat exchanger. For this purpose an air inlet plenum chamber is mounted to one side of the housing and draws air through an inlet immediately adjacent the side of the lighting fitting and a similar air outlet plenum is provided on the other side whereby air flows out immediately adjacent the lighting fitting.