(to be completed for each sash size)
When designing a system for multiple window sizes, choose the window with the highest width/height ratio to check for system feasibility.
|a)||Overall sash opening height||________inches|
|b)||Single sash dimensions:||sash width||________inches|
|e)||Available vertical space in weight pocket calculated by measuring from the heel of the side jamb to the bottom of the sash pulley housing less 2" for attachment of the counterweight||________inches|
|f)||Vertical travel requirement (a - c)||________inches|
|g)||Maximum counterweight length (e - f)||________inches|
|h)||Weight of unglazed sash||________lbs|
|i)||Glass size (total area)||________sq. inches|
|j)||Weight of glazing per square foot||________lbs|
|k)||Total weight of glazed sash (i x j) + h||________lbs|
|f)||Weight of single counterweight (k/2)||________lbs|
Calculate the length of the sash counterweight needed*, and compare that dimension to the maximum counterweight length computed in step g above. This will determine the feasibility of the proposed design.
* Consult manufacturer's literature for sash counterweight dimensions.
Note: These two examples show calculations for a weight and pulley window system. The first example shows the window with single glazing, the second with double glazing.