日本国内で産出された石炭はその９８．３％までが瀝青炭と呼ばれるもので、それを家庭用の竃や七輪に使うことは困難だった。発熱量あたりの単価についてみると、都市部での石炭価格は薪のおよそ半額、木炭の３０％程度であったので、価格的には石炭は経済的であった。しかし煙と炎の質の問題から石炭を厨房で使うのは難しく、暖房に使おうとすると大きな煙突付きストーブを必要としたので、北海道を除いて石油は家庭用暖房には利用されなかった。このような理由から、日本家庭における石炭は風呂用に特化した。
As much as 98.3% of the charcoal produced in Japan were those called as asphalt charcoal, which were not suitable for use with charcoal stoves or clay charcoal stoves in homes. In view of the unit cost for calorific power, charcoal in urban cost only half of firewoods, and 30% of wood coal. Charcoal was more economical in cost. However, it was difficult to use in kitchen for the characteristics of its smokes and flames. For heating use, it also requires heating stoves with large chimneis, therefore it was not much used at homes for heating except in Hokkaido. For these reasons above, charcoal became exclusively used for heating up the water in the bath in Japanese homes.
