Insulated Windows: From Cynicism

to the “Wow” Factor

 By Bill Primavera

The Home Guru


“Wow” is always a good response to hear from customers or clients who are considering any kind of purchase, right?


And in real estate, whether the exclamation is prompted by pulling up to a home with great curb appeal, or ascending a handsome staircase and peering down to the impressive living space below, the “wow” response always tells the realtor that the job of finding the perfect property for that client can now more easily coast to a comfortable conclusion.


I heard myself say “wow” spontaneously the other day at a demonstration of the effectiveness of the top rated types of insulated windows at the showroom of Franzoso Contracting in Croton-on-Hudson, a company long known for quality window replacement and other home improvement services. 


I was set up to be impressed by a preliminary conversation with Mark Franzoso, founder of the company, who explained to me the basics of energy efficient windows. When he said, “We offer windows only between the U-factor range of .30 to .18,” and I responded, “Huh?,” we both knew I needed more  information,


Franzoso then outlined the fundamentals of energy conservation in terms of measuring effectiveness by both U values and R values, admitting that the understanding of these values, or even talking about them, can be confusing. Basically, U-value measures thermal conductivity.  A lower U factor means a better insulated window.  R-value refers to the resistance of the window to heat conduction and is the inverse of the U-factor.  Better energy efficient windows have high R-values and lower U-factors. Confused yet? To keep it simple here, let’s refer only to the U- factor.


To demonstrate the U-factor associated with different types of window construction,   Franzoso called in Doug Toback, president of sales management, who introduced himself by saying, “You’re the Home Guru, and I’m the Window Guru.”  While not usually a hard-nosed reporter, I opened my interview with a somewhat cynical question based on a warning from a well-meaning friend who had advised me not to be lured into a more expensive three-paned insulated window, when double-paned windows would do just as well.  I wanted to know the difference in effectiveness between the two.


Toback smiled, and said simply, “Hold on.” He left the room for a moment, then returned with a big black box containing a selection of different types of window samples.  He placed an infrared lamp on one side of a table, with a BTU reading device three feet from it. Between the two, he positioned the first type of window pane, a single pane of glass, and asked me to place my hand behind it. The conduction of heat through the window was as though there was nothing solid between the heat source and my hand.  The BTU reader registered a high number for conductivity, going from an original number of 600 to 480.


When the window progressed to two panes with just an air space between them, there was just a nudge of a difference, with the number on the meter decreasing from 480 to 434.


But, wow (this is the point at which I said it), when the double pane window featured the addition of Argon gas, heavier than air, in the open space, the conductivity of heat dropped on the meter from a reading of 434 to 66. There was practically no feeling of heat on my hand behind the window. And, when the window progressed to three panes with Argon gas, the reading fell from 66 to 18. Another product used to lessen conductivity is Krypton gas (yes, that’s right, from Superman land).  “Not even Superman could penetrate this Krypton,” Toback joked. And in testing the triple paned window filled with the latter gas in the open space, the meter reading dropped still further from 18 to 14, and I could feel no warmth whatsoever on the far side of the window.


Fransozo stepped in at this point to place a panel with fiberglass insulation between the lamp and the meter, approximating the transmittance of heat through a solid wall, and it was the same low reading.  Triple pane windows with one of the insulating gases in the space between them, in other words, are equal in energy conservation to a solid wall.


When replacement windows are selected by consumers, appearance is usually the first consideration, followed by initial cost. But if energy efficiency were something that could be seen and touched, it would be first on the list. Look at it this way.  Windows are basically thermal holes, through which the average home loses 30 percent of its heat or air-conditioning energy.


It all adds up to knowing what you’re paying for and whether a larger investment upfront pays off in the long run.


When I think of the years in which I’ve been losing 30 percent of energy through my windows, I realize that I could have paid for replacement windows many times over and, at the same time, significantly lower my annual heating and air-conditioning costs.


After the “physics lab” demonstration at Franzoso, I know exactly what to request when I replace my windows. Those that produce the highest efficiency rating, or the lowest U rating, may cost more initially, but in the long run, they win the race in performance and savings. If a picture is worth 10,000 words, this demonstration to me was worth a million.


Franzoso Contracting can be reached at 914-271-4572, and its website is


Bill Primavera is a licensed Realtor® (, affiliated with Coldwell Banker, and a marketing practitioner ( He can be emailed at or reached directly at 914-522-2076.