What I'm Seeing Now

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Heating And Cooling Everything On The Way To The Room You Want Heated

When you have an older furnace and duct system, the older metal ducts end up heating and cooling everything on the way to the room you want heated.

Metal ducts are very leaky.  There are lots of seams and bends, corners and connections.  Each of those locations leak air, both heating and air conditioning.

Metal ducts are more efficient in that air flows more easily.  There is less corrugated surface area to impede air flow.

But they have to be treated or taped so as not to leak.

Modern building techniques paint metal duct joints with a latex slop to seal them off.  It works great!  And ducts in environmentally-vulnerable areas like attics and crawl spaces are insulated to not bleed off their conditioned air.

But not in the olden days!

I had a client who wanted to buy an older house.

As we spoke on the phone he was saying that one reason he likes the older home is because the HVAC air blows more efficiently in the metal ducts.

I said there are two ways that might not be true:

1.  For the reasons explained above, and I said that I could demonstrate it with a thermal camera.

2. Older duct work can be too small and confining for newer HVAC systems in that they want to draw in and blow out more air.  Particularly heat pumps.  The smaller, fixed ducts can create a bit of a blockage, which affects the efficiency of the system over time.

That number 2 can be significant!  It can wear down a heat pump, and kill it more quickly.

But, I walked around with my client and we could literally follow the ducts as they left the unit, went under the floor or up the walls, and then across a ceiling to service a bedroom two floors away.

Some of those ducts were 40', 50' and 60' long!  That is a lot of lost efficiency INSIDE THE FLOORS AND WALLS!

In this image you can clearly see two ducts that are passing up a wall.  In this case it's the living room wall, beside the fireplace. 

The orange and yellow areas show warmth!  You can see that even the floor molding at the bottom of each is getting warm!

The drywall at the warmest spot is 125F!  At this point the ducts are only about 10' from the unit.  From here they go up, turn left and right, and, passing above the main-level ceilings service a bedroom in the front and in the rear of the house.  Each of these is about 40' from the furnace to the bedroom floor.  Those walls will similarly cool down during the AC season.

My client was amazed.  Mighty Mo is amazing!  And yes, Mo was kind enough to snap a thermal image of the client for his scrapbook.  Using a thermal camera to teach is always a BEST PRACTICE!

My recommendation:  there are plusses and minuses to old and new construction.  Some things in older construction have to be lived with however.  The fix for this particular issue would be difficult at best, and expensive, if it is even possible!  The break even on this "remodel" might never be realized!

 

 

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 17 commentsJay Markanich • May 08 2013 03:47AM

Comments

Thank you for the information. I like newer homes because they are more energy efficient.

Posted by Gita Bantwal, REALTOR,ABR,CRS,SRES,GRI - Bucks County & Philadel (RE/MAX Centre Realtors) over 7 years ago

That they are Gita.  Especially if one pays attention to extra insulation.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Hi Jay,

I had the older home a couple weeks ago that had the ducting running in the walls. Upon further investigation it was a balloon framed home and the ducting was connected to the framing cavities. Without any ducting in the walls. The heating and cooling ran right through the wall cavity with no duct work.

Talk about energy loss.

Have a great day in Bristow my friend.

Best, Clint McKie

Posted by Clint Mckie, Desert Sun Home, Comm. Inspection 1-575-706-5586 (Desert Sun Home, commercial Inspections) over 7 years ago

I have seen return ducts like that Clint, but never service ducts!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

If they are not insulated there will definitely be a loss of efficiency. I hate flex ducts, I have them in my house too :-(  If I had your money I would re-do them all with duct board! Quack!

Put your PF's on and have a great day Jay!

Posted by Fred Hernden, CMI, Albuquerque area Master Inspector (Superior Home Inspections - Greater Albuquerque Area) over 7 years ago

Great job of using technology to get your point across.  Looks like lots of heat loss there!

Posted by Marc McMaster, Putting my clients before myself (RE/MAX Centre Realty) over 7 years ago

Fred - ducts in the 60s did not have insulation.  And flex ducts are good and bad.  But my PFs aren't and will be on all day!

Marc - heat and cold!  People did not understand inefficiencies then or now.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Jay, Might Mo never lies. In this case he will just have to live with it.

Posted by Michael Setunsky, Your Commercial Real Estate Link to Northern VA over 7 years ago

Jay, as long as all the ductwork is inside the thermal envelope how is there really any "loss" of heating and cooling along the way?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

That's the way it is Mike!

Charlie - the furnace room is heated unnecessarily, and over the house probably 200' of drywall is heated unnecessarily.  The bedroom where the heat is supposed to go does not benefit from that. Not a loss to the outdoors perhaps, but to the point of heating yes!

But, that bedroom was so slighted I heard it complain when I went in...

The living room, in contrast, was smiling.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Jay -- Mighty Mo has demonstrated a great loss of heat - not getting where it belongs.  Another great way to show the client what is happening, in a way they will be able to understand.

Posted by Steven Cook (No Longer Processing Mortgages.) over 7 years ago

It's a shock to see your whole house lit up like that Steven!  All the walls and ceilings were glowing!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Man that is one big house :)

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

Not at all really Charlie.  The furnace is at one end of the house, so the ducts have to go here and there, up and over, and to service every room.  Much of that ductwork is behind walls or ceilings.  I'm guessing at the total linear footage, but I might be conservative.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Looks like the Mighty Mo calls it like he see's it.  The seller will need to do some repairs looks like or up the fire insurance.  :~)

Posted by James Dray, Exceptional Agents, Outstanding Results (Fathom Realty) over 7 years ago

Good morning, Jay. It is amazing what these thermal imaging cameras can do. I am contemplating investing in two of these for my other inspectors...

Posted by TeamCHI - Complete Home Inspections, Inc., Home Inspectons - Nashville, TN area - 615.661.029 (Complete Home Inspections, Inc.) over 7 years ago

This is typical of older, metal ductwork James.  There's no fire hazard!

Like I've said before, Michael, practice, training, practice, training, practice and training.  And having fun with it before you use it for real!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

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