Is it worth replacing this flex pipe with hardpipe

Question

We're the second owners of a home built in 2015, and a HVAC technician recently pointed out that our basement furnace piping uses long runs of flex pipe, where hardpipe should have been laid.  He said that airflow can become turbulent in these and will be improved with hard piping.
Looking to confirm this information.  My residence is a 2200sqft + finished basement with a decent furnace system.  Is the air flow in such a residence typically fast enough such that runs of flex piping would disrupt airflow?  I have noticed that vents in the first floor that attach to these do feel weaker than the ones in the second floor of my house and thought maybe this was the reason.

Ed Beal · Accepted Answer

Flex pipe is the lazy way to put in ducting.
I think it should not be allowed for trunk lines and yes you were told correctly it is not as efficient because of the turbulence.
I am guessing this was a diy home because of the cobbled sections of round pipe to flex duct in the photo.
Unfortunately some use it more than others I only use it for short sections from the trunk to the registers.
Installing regular pipe will improve the flow the longer the flex replaced the bigger the improvement in flow you will see.

MonkeyZeus · Answer

It's hard to answer this:

Is it worth replacing this flex pipe with hardpipe?

without knowing what quotes you received or your budget.
Based on a recent estimate I had for HVAC I would guess you're looking at $1,500 to have a professional do it and it should take them 1 day or less. This estimate is based on your pictures only so if there is more work then expect to pay more.
If you do it yourself then expect to pay about $200; this assumes you have the tools already. If not then add $100 for tools and you'll easily sink a weekend or two doing this project.
Will it fix weak air flow? Possibly. Flex pipe is supposed to be sized up compared to hard pipe. So a 6 inch hard pipe is equivalent to an 8 inch flex pipe.
Were corners cut? Yes, clearly. Are they life threatening? No. The house passed inspection because UL listed HVAC materials were used.
It's a done deal, after inspection you agreed to buy the house as-is so it's your problem now.
Welcome to home ownership!

Is it worth replacing this flex pipe with hardpipe

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