Indoor heating; devices or systems used to warm interior spaces (used to raise room temperature in cold seasons).
冬は暖房をつけないと寒くて眠れない。
In winter I can't sleep without turning on the heating because it's too cold.
このアパートは暖房がよく効く。
The heating in this apartment works well.
光熱費を節約するために暖房の設定温度を下げた。
I lowered the heater's setting to save on utility bills.