Small window unit does nothing for big house

Grandma has a nice big house so I was surprised that no one was staying over at her house for the family reunion. Everyone was staying in hotels. When I asked why, I was informed that Grandma doesn’t have air conditioning. However, when I talked to Grandma, she assured me that she does. I wanted to save money so I chose to stay at her house. The moment I walked into her house, I knew I had made a mistake: the house was very warm. Grandma had one window air conditioning unit in the living room and that was it. And this window unit was small. It was made for one small office or room, not a big old house like Grandma has. Needless to say, I didn’t get much sleep that night. My room was very hot and uncomfortable. I could hear the air conditioner running in the other room but couldn’t feel it at all. Grandma, on the other hand, said she was perfectly comfortable. During the family reunion I brought up the idea of all of us going and together to get central air conditioning installed in Grandma’s house and she wouldn’t hear of it. She said that she rarely ever even ran the window unit and only turned it on because I was coming. I took the couch in my brothers hotel room for the remainder of my trip. I told Grandma that we had some catching up to do so that her feelings wouldn’t be hurt, but really, I just wanted to sleep in an air conditioned room.