Earlier quoted context omitted.
You’re ignoring one critical difference between these two scenarios. Humans, and all human related activities, produce heat as a waste product. It’s much easier, and consumes less additional energy, to heat an occupied space, than to cool it. Thanks to the fact that your average human produces 80W of heat just to stay alive. So every human in your cold space is 80W fewer watts of energy you need to produce to heat th…
I also point out that Phoenix's "summer" last longer than Berlin's winter: https://weatherspark.com/y/75981/Average-Weather-in-Berlin-G... https://weatherspark.com/y/2460/Average-Weather-in-Phoenix-A...
For each day, use the average high and the average low. Subtract the desired maximum dwelling temperature from the average high: if the result is positive, add it to the cooling degree-days total. Subtract the average low from the from the minimum dwelling temperature: if the result is positive, add it to the heating degree-days total.
Over a year, that gives you comparable figures on how much you will need to cool or heat the space. Many agencies calculate this for specific areas.
Here, for example, are the current season numbers for Boston: https://www.massenergymarketers.org/resources/degree-days/bo...
Generic regional numbers for the US: https://www.eia.gov/energyexplained/units-and-calculators/de...