Duct designing software

[dileepa]

I'm dileepa who worked as mechanical engineer in Co-energi pvt ltd. We design duct system, lighting system , building managment system. So I want to know what are the best software to use for duct designing system. And simulation also. Can you tell me what are the best software to do my *
Thank you.

Regards,
Dileepa
(Mechanical Engineer- Co-energi pvt ltd)