2gb

A sash window is a window that has at least two separate panels of glass. Doesn't matter if one of them slides or tips or tilts to open up the window, the minimum requirement is simply 2 panels of glass.

It insulates the window and keeps heat in.

Yes

melting loss very in all castings from 2% to 50%.

If you melt aluminum pure ingots & cast within minimum holding loss is 2%. If you cast in small batches it will go up to 15%.

If you melt aluminum scrap & cast within minimum holding loss is 15%. If you cast in small batches it will go up to 30%

If you melt aluminum turnings & cast within minimum holding loss is 25%. If you cast in small batches it will go up to 50%

melting loss very in all castings from 2% to 50%.

If you melt copper ingots+zinc ingots & cast within minimum holding loss is 12%. If you cast in small batches it will go up to 35%.

If you melt copper turning+zinc &chips & cast within minimum holding loss is 25%. If you cast in small batches it will go up to 50%