how do you convince a customer to change their mind from hard pipe to flex duct. I know hard duct is better, but i don't like to do the extra labor.
tell them the price difference
Better Idea !
Explain to them the difference;
Spiral Flex duct has some restriction .125% ;but does improve the quiet flow of air and less air loss because of less connections.Improved insulation on flex duct R-8.
Metal round pipe has more joints to leak air, contracts heat and cold more.Rust due to condensation over time.
Airflow in metal is some what louder..
But, the cost difference in metal 90* and metal wyes and labor cost to install ;far out weight the small barrier of spiral flex.
What ever choice is made the amount of air will flow through either if size according to Manuel D.
As Dennis Miller would say:
"That's my opinion I could be wrong".