window balance

A contractor from pasadena says:
I have it narrowed down to 28" 351 needed I just don't know the different options and what they represent. The one is a large oriel single hung(34x66) the other is a regular size bedroom dh (32x54). Please advise. There stamps have faded and only state UNIQUE.
Profile picture of Tom
Tom from SWISCO responded:
Did you see the chart we have posted under the S351-28's pictures? This shows each option and how much weight they can support. There is also a brief description explaining what options are, in general. All you need to do is weigh your sash on a scale and compare its weight to the chart.
A contractor from Pasadena says:
Other thay weighting the window is there a way to approximate based off sash size.
Profile picture of Tom
Tom from SWISCO responded:
I wouldn't recommend that. There are a lot of factors outside of sash size that you have to consider, such as the material of the sash frame, the type of glass, etc. All of these things affect the weight and if you go only by the sash size, you can't depend on it being accurate. The easiest and most sure-fire method is to simply weigh the sash on a scale.
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)