The earliest sunrise of the month in Dublin is 5:41 AM on August 1 and the latest sunrise is 51 minutes later at 6:32 AM on August 31. The latest sunset is 9:20 PM on August 1 and the earliest sunset is 1 hour, 4 minutes earlier at 8:16 PM on August 31.
1.2 kWh x $0.25 = $0.30 per hour to run your window air conditioner. At 8 hours a day for 125 days of summer, your window air conditioner will have an annual running cost of $300 a year.
To continue the earlier example of the window fan, if energy costs 17 cents/kWh in your area, running the fan as estimated earlier for one year will cost you approximately 1.25 (kWh per day) * 365 (days--the time period) * .17 (cost of energy/kWh) = about $77.56 per year if you use the fan every day.