Internal fans will make it use more gas because the thermostat will never cut out. The thermostat is designed for a static plate evaporator, which should switch off at around -11c. That will never happen with a fan blowing on it.
External fans will reduce gas usage because they will lower the condensing temperature of the refrigerant... the evaporating temperature will come down with it and thermostat cut out sooner.
That's the theory anyway![Smirking face :smirk: 😏](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f60f.png)
External fans will reduce gas usage because they will lower the condensing temperature of the refrigerant... the evaporating temperature will come down with it and thermostat cut out sooner.
That's the theory anyway
![Smirking face :smirk: 😏](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f60f.png)