Very simple a outdoor unit and indoor unit to control the Hot & Cold, in bases only. The ventilator needs to be only for air control in bases not controlling the temp. Next maybe add cameras and monitors so players can monitor things outside what is happening around the base.
Heat pumps only work within a certain temperature range, and only in places where you can actually use them. They wouldn't work on planets or moons with no atmosphere, for example, or extremely hot or cold places (of which there are many). Wouldn't work on space stations or ships either.
