What is the ruling on a husband saying "it's normal" after he swore an oath that the air conditioner would not be installed, and then it was installed?

If a husband swears by Allah, or by one of His attributes, or by the Qur'an, and then breaks his oath, he must offer expiation for the oath. The expiation for an oath is to feed ten poor persons with an average meal, or to clothe them, or to free a believing slave. Whoever cannot find any of these, then he must fast for three days, as Allah Almighty says: "Its expiation is the feeding of ten poor persons from the average of that which you feed your [own] families, or clothing them, or the freeing of a slave. But whoever finds not [the means] - then a fast of three days. That is the expiation for oaths when you have sworn. And guard your oaths. Thus does Allah make clear to you His verses that you may be grateful." [Al-Ma'idah: 89].