New Ductwork Sizing

[Mastermech]

I had a new furnace installed last year and unfortunaly could not afford the ductwork portion. I know my trunks are grossly undersized and would like to replace them. I have done some calculating and it seems the other ducts are sized right but I would like to investigate further. Could anyone point me in the right direction. Any reference books I might look through or a Manual D worksheet perhaps. Thanks

[wayne]

This company offers trial software that you should be able to use to check your sizing!

Wayne