I've heard that air conditioners in foreign countries are not very energy efficient, and aren't good for the environment.
It seems that air conditioners in foreign countries are not very energy efficient, and aren't good for the environment.
「 ~ らしい」は I've heard that （聞いたことがある）か It seems that （ ~ のように）で表現できます。
海外 foreign countries
エアコン air conditioners
エネルギー効率 energy efficient
悪い aren't good/not good
らしい I've heard that/It seems that
参考になれば幸いです。
The air conditioning in a lot of foreign countries isn't very good for the environment.
この場合、次のような言い方ができますよ。
ーThe air conditioning in a lot of foreign countries isn't very good for the environment.
「多くの外国のエアコンはとても環境に悪い」＝「エネルギー効率が悪い」
isn't very good for the environment の代わりに isn't very eco friendly とも言えます。
ご参考まで！
オーストラリア 
カナダ 
