Hot Rooms in an $850,000 Home!! Is Flex Duct to Blame?
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- Опубліковано 3 чер 2024
- Is rigid duct always better than flex duct? No! It is all about the install for both of these products. However, I am learning that when a builder chooses flex duct because they think the product can be cheaper, they usually also go with the cheapest bid for the installing contractors. This means that I see many more poorly installed flex duct systems than rigid duct systems.
This very nice house by a prominent high end spec home builder is no exception. What seemed to be a decent (although far from perfect) install in the main attic turned out to be a disaster when the installers pinched lines as they fed them through a narrow attic wall.
The result was as to be expected. The west bedroom was starved for air and the upstairs media room (closest to the air handler) was frigid. The homeowner had to pay another HVAC contractor to come and add dampers to put a band aide on the problem, forcing more air into the bedroom.
What was the right solution? To install the flex duct correctly from the beginning - no pinching, kinks, tight bends and pre-stretching the duct before install. Adding dampers at initial install would also allow the system to be tuned as the HVAC contractors TESTED(!) the system before the homeowner moved in to insure that each room had the designed airflow.
The current state of HVAC installs in spec homes is abysmal, but it is not a blanket indictment of flex duct.
Jordan's Rules for a Successful HVAC Strategy
Design the System (manual j or other)
Install Correctly (read and follow all manufacturers instructions)
Test, Adjust, and Verify System Performance against the Design!
Hey Jordan, was a residential builder 28 years ago. I'm just getting around to designing our final house near Mt Hood Oregon. I thoroughly enjoy your videos as well as Steve B...am using them to help me catch up on the innovation and new products, systems etc in home building, though have tried to keep up over the years.
Keep up the content and enthusiasm
all the best,
Thanks so much David! Good luck with your own home. Exciting times!
I was in the HVAC business my entire career. I have never seen hard pipe fail. I used 12” of flex where I connected the pipe to the trunk to eliminate noise. Duct work if at all possible shouldn’t be in an attic, in both winter and summer you have energy loss. The attic may be R60 but the ducts may be R8 creating convection currents . The system in your video is called the octopus, I have seen them but never installed them. You are correct about commissioning the system but it isn’t really practical for residential construction, the next best thing is good design and installation.
Completely agree on the good design principle (see, I get it right sometimes @cybercusal ) of having the ductwork ran through conditioned spaces. I wonder why you think commissioning a residential system is impractical? If the house is to be Energy Star rated (a pretty easy bar), a rater already has to come and inspect the system for refrigerant charge and fan air flow. Balancing the system is recommended (but not required) and is pretty simple with a trash bag and hanger. Maybe I will do a follow up video showing the poor man's method of checking air flow to each register.
What is the poor man's way of balancing?
Without commissioning, how do you even know the system is functioning properly or at all? Design, Install, Verify.
@@N-M424 I could go and commission a system when the temperature was between 45 to 85 degrees, measure the airflow and temperatures and compare with the design and would find everything working on all but the worst installs. Extreme conditions will reveal the problems and there cause. One call back I had was in a master bedroom hat when it was cold, about 15 degrees the bathroom was around 60 when the rest of the house maintained 70. Was I at fault? No, an infrared gun revealed that insulation was missing behind the tub enclosure. Here’s what I would tell clients, your system should be within 2 degrees throughout the home, if not call me. I didn’t receive many calls, experience and good design and installation insured that.
@@paulmarc-aurele5508 Good design and install won't prevent issues from poor design and installs of other trades, you just proved that with your story. Not commissioning and verifying your work is correct is lazy and poor practice. At the end of the day the customer just wants their bathroom not to be cold. How is that going to be accomplished? More heat in, or less heat out?
That's painful to look at. But that's 90% of the central AC systems in Texas. Rigid ducts would also fall apart if they were strapped to the underside of the roof deck with chewing gum and shoe laces.
Rigid duct is far superior to flexible duct. 1. Mice and other pests cannot chew through them 2. Static pressure is stable if designed properly 3. Noise is only present when poorly designed. Short of it if you want the best system run rigid trunk lines and 6' dampered flexible branch ducts. This is what my company specializes in. If you have in wall ducts or tite spaces this can be done by properly designing rectangle ducts with turning veins. Rigid ducts are much more expensive due to higher material and labor costs but you never have to worry about hot/cold rooms.
I am really dismayed at the builder homes in Florida. They are still building like it’s 1975 in regards to AC. We have looked at new houses that are all over 800,000 and it’s builder grade crap. What’s the answer?
People (buyers) don't want to pay to do it right. That is the problem. They want $$$ spent on kitchens and bathrooms 😞
Bro can't even spell principal correctly 😂
I am an autocorrect feind, feend, fiend... :)
Just re-watched to see what I screwed up... I didn't misspell, I just consider myself a rule or guideline more than a person in charge. :) Thanks for watching and commenting!
If you just want to verify that the CFM is correct no problem. I like to ensure that each room is the same temperature which can only be done when it’s hot or cold. Sometimes the temperature is wrong due to construction deficiency’s that an anemometer won’t reveal.