My electricity bill came out to 400,000 won this month. lol

Usually, the electricity bill is around 200,000 to 220,000 won in the summer, but it came out quite high this month. lol
We are a family of four, with 4 rooms and 4 air conditioners. There is no air conditioner in the living room, though.
Two of them are inverter types purchased less than 5 years ago, but the other two are constant-speed types that are over 10 years old. lol
Especially this year, since my daughters are on school break, they keep them running constantly except when they are out, so it's becoming unbearable. lol
Since last year, my second daughter has hit puberty and stays cooped up in her room with the AC on all the time. T_T
Especially since the indoor temperature exceeded 33 degrees for 2 to 3 weeks in August, there was no other way... T_T
Should I quickly replace my daughter's air conditioner with an inverter type? T_T