My pedal harp used to pop strings quite often, it was in the living room near the front door. So even though our windows were closed it was apparently getting temperature changes from the door alone. I moved my harp into my bedroom, I keep the door closed and don’t open the window anymore. The rest of the house has a nice breeze when we open up the windows but my room will stay nice and at an even temperature all seasons. My advice would be to pick a “harp room” and try and keep it as stable as possible. I hope that helped, God Bless!
— Natalie