Thanks. I am wondering about the right length. It seems like the length of the old spiral balance is not necessarily the right length, because the old and new operate differently. The old one sits in a channel in the bottom sash and is anchored to the window frame at the top of the bottom sash. It moves up and down with the sash and is never visible. The new one is anchored at the top of the upper sash, right? That is 31" from the top of the bottom sash.
Yes, you are correct. If you'd like us to calculate the balance length for you, please give me the height of the glass for both the top sash and bottom sash. Thanks!
The glass height is 30 inches in the top sash and 29 1/2 inches in the bottom sash. (The top sash is fixed, and I'm looking for a balance for the bottom sash.)