Is it a reverse cycle A / C unit also used for heating in winter or at night, in which case it will pump out colder air then that doesn't rise? (skepticalscience.com)
If you're keen to retain heat in winter months pleated blinds — with aluminium backing — will help to control the temperature. (madetomeasureblinds-uk.com)
Design and layout of windows, walls and floors collect, store and distribute solar energy in the form of heat in the winter and block solar heat in the summer. (rismedia.com)