My mom and dad’s house is pretty big.
It’s also an older home.
My parents have owned it for over 30 years but they are like the 3rd owner of the place. When mom and dad first got the place, they had to change the HVAC equipment to a more modern style. Initially, the house came with a boiler in the basement and there were several window unit air conditioners as well. My folks put in gas furnace and a central air conditioning system. It was quite an ordeal to get done as there were air ducts to run and the whole thing. But it turned out great and the heating and cooling in that house is still very nice even though their first HVAC units have be replaced. But one thing that sort of bothered my old man for a long time was that a small office on the second floor just didn’t get the heating and cooling he felt it should. The HVAC technician explained that there were a variety of reasons for that room being hotter in the summer and colder in the winter. Yet, it took 20 plus years before my dad figured out just how to deal with it. What he did was get some room to room ventilator fans. These things go inside adjoining walls. And they then pull or push air from surrounding space to get more heating and cooling inside that room. It worked like a charm when he first gave it a try. But he does go on that it took him such a very long time to figure out just how to remedy the situation.