YSK You can save a lot of electricity and money in dry heat by closing your blinds and windows during the day and airing out your house at night when temperature is low.
from /r/YouShouldKnow
YSK 昼間はブラインドや窓を閉めて、夜は気温が低いときに空気を入れ替えることで、乾燥した暑さの中でも電気代とお金を大幅に節約できます。