What I'm Seeing Now

head_left_image

She's (NOT) Gonna Blow, Captain!

One very important aspect of a pre-drywall inspection, is to check for proper distribution of HVAC systems.  Modern HVAC distribution tubing includes a lot of flexible stuff, a slinky really, made up of a slinky-like spring, wrapped in plastic, surrounded by insulation and then another final layer of plastic. 

Another thing to look for is how the flexible ducts have been treated.  Slinkies, if you recall, were easy to manipulate.  They could be smashed and come back springing!

At times these flexible ducts are wrapped so tightly around joists or roof rafters that they are literally crushed. 

The more they are crushed the less they are able to blow air.

You want them to blow air!

Sometimes rooms are hot or cold.  Part of the reason might just be that they are not getting enough air introduced to control the temperature environment.

 

The duct to the left services a rather large master bathroom.  It is a 6" duct and should blow 400 to 600 cubic feet per minute of air (cfm).

Hard to see in the photo, but easy when up close, is that it was bent so much that the opening just above the hole is only about 2" wide.

That won't blow much air.

It also becomes a problem long term in that closing off this opening causes back pressure inside the duct and can literally pop the duct off of the main trunk to which it is attached.  I see popped-off ducts all the time!  Then the attic is conveniently heated and air conditioned!  Excellent!

The pre-drywall inspection is the time to catch this!  Once the drywall is up and the register is in place, it is much harder to see the size of the opening servicing a room's register.

My recommendation:  the next time you are walking through new construction, look around, and especially up, to see how the flexible HVAC ducts have been treated.  Is the distribution even and logical?  Are they wrapped too tightly?  Or bent severely around a joist or rafter?  Or maybe even torn?  This is crucially important to the final operation of the system and the comfort of the home.

 

 

Jay Markanich Real Estate Inspections, LLC  

Based in Bristow, serving all of Northern Virginia.

Office (703) 330-6388   Cell (703) 585-7560

www.jaymarinspect.com


Comment balloon 43 commentsJay Markanich • October 12 2010 08:50AM

Comments

Jay, A new risk versus the old metal ducting.  Could see how it wouldn't take much to crimp the tubes.

Posted by Liz and Bill Spear, RE/MAX Elite Warren County OH (Cincinnati/Dayton) (RE/MAX Elite 513.520.5305 www.LizTour.com) about 8 years ago

Yet another great reason for pre-drywall inspections. Excellent post!

Posted by Kathryn Maguire, Serving Chesapeake, Norfolk, VA Beach (GreatNorfolkHomes.com (757) 560-0881) about 8 years ago

Seems like a common sense thing that the builder/HVAC installation folks would make sure is not a problem...but it is not "their" house so they rarely care!

Posted by Gary L. Waters Broker Associate, Bucci Realty, Fifteen Years Experience in Brevard County (Bucci Realty, Inc.) about 8 years ago

Well, it really doesn't take much Bliz and that can only be addressed up front during the installation.  It is very important to check for this on a pre-drywall inspection.

Thanks again Kathryn!  There's a lot to look for on these inspections.  It is the only opportunity to see the house skeletally.

Gary - we are back to the common sense thing!  And, as we know, due to scarcity, that commodity is going for a lot per pound on the international markets!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Torturing the air flow...

Jay, I bet you see this a lot in ductwork to/from bonus rooms over garages.

Posted by Mike Jaquish, 919-880-2769 Cary, NC, Real Estate (Realty Arts) about 8 years ago

Jay,

One of the many reasons I subscribe to your blog, great reporting! I will be re-blogging this of course. Thanks again, you explain everything so well. :D

Posted by Valerie Duncan Stewart, Real Estate Agent-Broker, OKC, OK ((Metro First Realty)) about 8 years ago

Jay:  This post definitely does not blow.  (come on you had to know someone would say it!)

Posted by Jim Allhiser, Salem, Oregon Home Inspector (Perfection Inspection, Inc.) about 8 years ago

True, Mike.  And they cut these small rectangular holes to accommodate a round duct and there is only one way it is going through - smooshed.

Valerie - thank you, and, again for the reblog!  Instruction is one of the reasons I spend time on AR, plus the entertainment value.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jim - you were tempted to finish it, weren't you?!  "Out yer..."  Go on, admit it!  ADMIT IT!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jay ~  Since reading your posts, I will forever strongly recommend a Home Inspector be involved from day 1 of the construction process.

Posted by Tish Lloyd, Broker - Wilmington NC and Surrounding Beaches (BlueCoast Realty Corporation) about 8 years ago

Most counties do their own inspections, Tish, of things like the site and foundation.  I would do whatever a client asks, but I usually only recommend two inspections - the pre-drywall and final.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jay, the flex duct is so easy to use, much cheaper to install and saves so much time. Too bad they didn't have an extra 6" of duct to spare to make that room more comfortable.

Posted by Ed Silva, Central CT Real Estate Broker Serving all equally (RE/MAX Professionals, CT 203-206-0754 ) about 8 years ago

They surely did, Ed, but just cut it so short there was no room except to crimp it.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jay, what a great explanation of what should be a "common sense" issue.  But some HVAC'ers and Builders want to cut corners or "Get 'er Done", so they install this kind of nonsense.

Let the air flow freely through the ducts! 

Posted by Fred Griffin, Licensed Florida Real Estate Broker (Fred Griffin Real Estate) about 8 years ago

Well, Fred, it has to or the system does not work.  It's funny how on so many of my posts people use the words common sense!  Most of what I report truly is!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

This is a great post...  I am not that familiar to HVAC systems, so I appreciate posts like this.

Posted by Chris Alston, Silicon Valley, California (Chris Alston (Keller Williams Realty, Silicon Valley, California)) about 8 years ago

Well, thanks again Chris!  My intention is to be instructive and hopefully some of these posts are!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Wow, you mean you have to have full size to those openings.  What next..

Posted by Jack Gilleland (Home Inspection and Investor Services, Clayton) about 8 years ago

I am amazed at the new standard imposed by home inspectors too, Jack, but yes, it's true.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Be sure during construction some type of screen has been placed over any floor ducts, I have found several different items swept into the floor ducts over time.  Also if the house has not been made water tight during construction often I have found water in the ductwork, which someone then pierced with a nail to drain the water out at t low point.  This can lead to other headaches down the road.

Posted by Mark Quaintance (Windermere Real Estate - Utah) about 8 years ago

Thanks Mark.  Actually I have suggested to clients that they vacuum their registers when they take possession of the house.  A couple of times I did find ducts that hung very low and felt heavy, only to find water inside!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Often when I find flex ducts off or loose it's because some one forgot to secure it to the trunk. That's what happens when people are in a hurry.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) about 8 years ago

Sure, Jim, and any looseness becomes so vulnerable to vibration, pressure, gravity or whatever and pop goes the weasel!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jay - But taking time to do it right just "crimps" an installer's style.  They don't call it flex-duct for nuthin'.  (When I was building I used to stuff insulation into all the openings just to keep out dust and trash--of course I had to remember to remove it later)

Posted by John Mulkey, Housing Guru (TheHousingGuru.com) about 8 years ago

Good insights and tips about the pre-drywall inspection. Many new homebuyers aren't aware of this, and even skip the final inspection. We need to keep educating the buying public.

Posted by John Novak, Henderson, Las Vegas and Summerlin Real Estate (Keller Williams Realty The Marketplace) about 8 years ago

John M. - that would go a long way toward protecting the ducts.  But gotta have that good memory!

John N. - that's the idea!  Pre-drywalls are essential!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

What an interesting journey into this subject matter.....I enjoyed your title too....well done and thank you Jay

Posted by Richie Alan Naggar, agent & author (people first...then business Ran Right Realty ) about 8 years ago

400 - 600 CFM?  Wow, that's a lot of air.  I wouldn't have guessed that much.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) about 8 years ago

Richie - I am glad you had a good ride!  Sometimes the titles are dumb, other times clever!  We try...

Reuben - actually the returned air is more important than the register's air flow, but enough air has to blow out to balance what is being drawn back in.

I have had another post similar to this one, and was taken aback by the "J sheet."  Heard of it?

http://activerain.com/blogsview/1554333/because-the-j-sheet-says-so

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Jay : Another very good reason to have a property inspection; whether it is a new home phase inspection or existing home inspection.

Carl Winters, Canyon Lake TX

Posted by Carl Winters about 8 years ago

Hi Jay, great points.  Frequently I have seen where all it would have taken was a minute more for the contractor to cut a slightly larger hole in the sheathing to not crimp the flex-duct.  A case of haste makes waste.

Posted by Dale Ganfield about 8 years ago

Cap'n... I'm not sure how much more she can take!!

Posted by Alan May, Helping you find your way home. (Coldwell Banker Residential) about 8 years ago

Jay, you always have good information for us REALTORS.  Thank you!

Posted by Margaret Woda, Maryland Real Estate & Military Relocation (Long & Foster Real Estate, Inc.) about 8 years ago

Jay, you always have good information for us REALTORS.  Thank you!

Posted by Margaret Woda, Maryland Real Estate & Military Relocation (Long & Foster Real Estate, Inc.) about 8 years ago

I believe that some people think it says "force it around and through duct" on the side instead of flex duct.

Posted by Troy Pappas, Virginia Beach Home Inspector (Safe House Property Inspections) about 8 years ago

Jay,

Even the ease of use stuff requires proper installation.

Rich

Posted by Richard Iarossi, Crofton MD Real Estate, Annapolis MD Real Estate (Coldwell Banker Residential Brokerage) about 8 years ago

Hi Jay -- Exceptional advice.  It seems in many homes that have 4-5 bedrooms on the upper level, that there is always one of the bedrooms that isn't heated/cooled properly.

Posted by Chris Olsen, Broker Owner Cleveland Ohio Real Estate (Olsen Ziegler Realty) about 8 years ago

Yes those things can be bad. They are easy to work with but damage easy and can become a fire hazard as they can collect a lot of lint.

Posted by Scott Baker, Realtor Homes for Sale in Cincinnati, West Chester, Mason, OH Area (www.eHomeReports.com Coldwell Banker West Shell) about 8 years ago

I have seen some of these things crushed so bad that it was obvious that they weren't going to flow... and the HVAC guys were saying "no, it'll be fine"...  They were saying that WAY less when they had to come and replace a bunch of duct under warranty. 

Posted by Lane Bailey, Realtor & Car Guy (Century 21 Results Realty) about 8 years ago

Jay, that is one of my pet peeves with flex pipes as well...

Posted by TeamCHI - Complete Home Inspections, Inc., Home Inspectons - Nashville, TN area - 615.661.029 (Complete Home Inspections, Inc.) about 8 years ago

Carl - there are many, many reasons, aren't there?!

Dale - they seem to cut the shortest piece possible, from my perspective.

Alan - that actually happens and they pop off!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Margaret - and hoping to be able to provide more of it!

Troy - the old FIAAT duct!  Doesn't have quite the ring, does it?

Richard - that is the point of lots of new materials - efficient yet easy.  But it still needs proper installation!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

Chris - I had a new house not long ago with a different system for the upper level, and one side of the house blew air and the other did not!

Scott - true and much harder to clean if you have the duct cleaning service over.

Lane - it's amazing how quickly things, and comments, can change!

Michael - there are more?  Gee, can't imagine why...

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 8 years ago

This blog does not allow anonymous comments