The company's air conditioner is broken, and the Korean property will be repaired.

First of all, the failure of the company's air conditioner depends on whether the air conditioner is installed in the original property or your company. From your point of view, it should be installed in the original property. Generally, this situation does not need to inform the property immediately in the form of letters, just call the property directly. If you notice the property several times or the door-to-door maintenance is not in place, you can send a letter to the property.

But if you are a large or standardized company, you can send a letter directly to the property, but the key to explaining the problem is communication, not notification.