I have a single hung, wood sash of 21 lbs. Height of 28" . From long point of sill to bottom check rail of top sash is 27". Jamb height overall is 54" from long point of sill. Top sash height is 27". Bottom sash is plowed out for 5/8" spiral balances. Bottom sash seems comfortable opening a distance of 23" from closed position. Seems to be a home made window set up and there were never balances of any kind present. Sash is held up with stick presently.
What spiral balances do you recommend?
![User submitted photos of window hardware.](/images/pictures/2016/04/68782.jpg)