A home owner from Lakeland says:
June 16, 2010
After reading the question about 28B and 28C, I'm assuming that for my balance stamped 28D I'll need to order the S380-29 balance with the option 2840, but I wanted to double check before ordering. Thanks.
Donna from SWISCO responded:
June 17, 2010
Most likely yes. To confirm, remove the window sash and place it on a scale.
29" Series 380 with stamp option 28D will carry a window sash weight range of 23 through 28 pounds.
This information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight.
Suggested sash weights are approximate.