Coil balance size

Question

Our bottom sash weighs 30lbs and has a triple coil balance that needs replaced. We feel almost certain we need the Series 160 coils. There is no stamp identifier on the old coils that we could find. Do we need three of the 4.5lbs coils (13.5lbs) or three of the 5.5lbs (16.5lbs) coils for the 30lbs weight of the sash? Also, when would the 15-111 pivot shoe be recommended compared to the 15-191 heavy duty pivot shoe? Our windows are white and we worry the gray will stand out so would prefer the white but want the best durable parts.

Paul · Accepted Answer

The 15-191 would hold up longer for heavy sashes like yours, especially if they're used often. The shoe shouldn't be visible once it is installed and attached to the sash pivot bar. For a 30 pound sash, I recommend using two S160-4 and one S160-5 for each side of the window. That would be three springs on each side, all told.