What I'm Seeing Now


A Thermal Camera Can See Window Inefficiencies

A thermal camera can see window inefficiencies.

The homeowners of this house had new windows installed.  They had bought into the ads telling them of marvelous savings.  "Save 35% on your energy bill!"  "100% guarantee!."

Statements like that are true, and FALSE!

A 35% savings may be achieved, but that does NOT apply to the entire energy bill!  Energy savings MIGHT be proved, and I say might  because proving it would be difficult at best, and that savings are derived from the new windows, but any savings have to be applied to the previous energy cost of the old windows versus the new.

The rule of thumb is that windows and doors have about a 30% effect on the overall energy bill.  To keep the numbers simple, of the old windows cost $100 per month in gas or electric during the heating months, a new bill of $65 MIGHT be anticipated from the new windows.  But divide that $35 into the total cost of installing the new windows - and in this subject house that cost was $11,000 - to derive how many months of savings would be needed to break even on the installation. 

My math says 314 months.  That's 26 years!  But if heating is only needed 4 or 5 months a year, that break even extends further out.  Yes, even a lifetime.

Mighty Mo looked at the windows in this subject house.  All looked like the images pictured below.  The outdoor temperature at this time was 14F.  We actually waited for this cold day to do the inspection.

This is the same window seen with two different thermal image palettes.

On reports I typically use the palette to the left because it is logical.

Yellow and orange indicate warmer temperatures.

Lavender, blue and purple indicate cooler temperatures.

You can see the coldest areas on the window to the left.

The indoor temperature is 75F.  The coldest spot near the window is 37F.  There is a folding wooden shade at the top blocking the thermal signature of the window at that location.

This window is inefficient at the edges, at the top and bottom, and where the two panels meet in the middle.  That is where most windows are most inefficient.  But also, this window is cold around around the framing itself!

The palette on the right is most instructive.  It looks to me like a good seal around the window was not done when they installed it.  See how cold the wall is at the lower edges?  You can almost see air "blowing" in.

One complaint in this house was the feeling of blowing air near the windows.  Heat seeks cold, and as heat escapes it mixes with the cold outside a convective loop is created.  The air begins to move.  Looking at the window on the right you can almost see the moving air.   And you can see how cold is being conducted into the wall.

This same convection is why wind is created during thunderstorms.  Hot and cold air meet, swirl together, and wind is the result.  The physics is not different here, albeit on a micro scale, and moving air can be felt.

My recommendation:  sales pitches are just that.  The pitch MUST have a grain of truth to be believed.  Not only do these new windows not provide the energy savings they were advertised to, but the installation seems to lack, and that adds even more inefficiency.





Jay Markanich Real Estate Inspections, LLC  

Based in Bristow, serving all of Northern Virginia.

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


Comment balloon 15 commentsJay Markanich • January 22 2016 02:37AM


Good morning Jay Markanich . Very good instructional post. For the most part, if their lips are moving, most salesfolks are lying.

Posted by TeamCHI - Complete Home Inspections, Inc., Home Inspectons - Nashville, TN area - 615.661.029 (Complete Home Inspections, Inc.) over 4 years ago

Sales pitches have to be thought through very carefully Michael.  Most hear the words, without examining the content.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

Good morning Jay Markanich ,

I'm impressed! You have illustrated some important facts. The problem is windows are marked in an inspection (which they should be) and then the buyers want the sellers to replace these marked windows. That is a lot of money for a seller and isn't that beneficial to the buyer! 

Posted by Dorie Dillard CRS GRI ABR, Serving Buyers & Sellers in NW Austin Real Estate (Coldwell Banker United Realtors® ~ 512.750.6899) over 4 years ago

Certainly one benefit to newer windows is that they operate easily, Dorie!  Old windows stick or have weak springs, etc.  But energy savings is not always derived.

But you pose an interesting question - does a buyer benefit from new windows when the price of the house reflects those new windows?  Figuring an interest rate of 2.5% for 30 years, an $11,000 cost would amortize to $30/month.  So, if I'm right, the buyer basically breaks even on the new windows!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

Good morning Jay! A great lesson to learn before you consider new windows! Enjoy your day!

Posted by Wayne Martin, Real Estate Broker - Retired (Wayne M Martin) over 4 years ago

And around here, Wayne, since new windows are white they will be harder to see in the blizzard this weekend.

Says he, with a wink.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

I tell this to clients all the time.  You do not replace windows for energy savings.  You replace them for comfort, sound control and to the maintain the building envelope---they will never pay for themselves in energy savings.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 4 years ago

Most of the sales pitches I have gotten say one statement or catch word that makes me turn them off... happens almost every time!

Posted by Fred Hernden, CMI, Albuquerque area Master Inspector (Superior Home Inspections - Greater Albuquerque Area) over 4 years ago

Ugh, those poor home owners. $11K later and they're still cold.

Posted by Kat Palmiotti, The House Kat (406-270-3667, kat@thehousekat.com, Broker, Blackstone Realty Group - brokered by eXp Realty) over 4 years ago

Well done Jay.  I think I would have to supervise the installation to make sure they didn't cut any corners. 

Posted by Stephen Weakley (Nationwide Mortgage Services) over 4 years ago

Charlie - it's cool when the springs work!  Beyond that, igloos are exceptionally efficient.

Fred - perhaps because you are listening!  People hear the good stuff and don't question it.  "Guaranteed!"  Works most of the time...

Kat - it was pathetic.  And guess what!  The company no longer does windows...   perhaps, um, too many call backs?  Complaints?

Stephen - interestingly, it was cold the day the installed most of the windows and they suggested the lady of the house not stay nearby as she would get too cold.




Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

I think Jay Markanich you need to start an online gallery of thermo art....appropriate for any room. Wanda can name the original prints and click and send them on their way from your internet gallery....a whole new business !

Posted by Sally K. & David L. Hanson, WI Real Estate Agents - Luxury - Divorce (EXP Realty 414-525-0563) over 4 years ago

Maybe an age-progression thing?

Like the handsome young man to the right as a baby.

And then, later, as a ghost?

Um, I'll think about it.

But thinking kind of gives me a fever.

So I shouldn't spend a lot of time doing it.

I'll think about that too.

But thanks for the idea!


Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

Never really thought about igloo designs.  Makes the point crystal clear.

Posted by Chris Ann Cleland, Associate Broker, Bristow, VA (Long and Foster REALTORS®, Gainesville, VA) over 4 years ago

Crystal clear?  As in ice?

Couldn't resist.  Yes, a opening covered with seal skin and another opening covered seal skin traps air, and the air acts like an insulator, Chris Ann.

Maybe our newer windows should use seal skin.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 4 years ago

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