Anyone who has followed the changes of mileage in cars, has realized that the fleet performance changes slowly because cars live about 12 years or 200,000 or so. A 10% improvement in mileage this year, therefore takes 12 years to work its way through the fleet. Buildings are worse. They might live 100 years or more, so it might be easy to build new energy efficient buildings, but we might want to move a bit faster than waiting 100 years for it to work its way through the complete building inventory.
In buildings it’s the envelope that determines how much energy is wasted. Obviously, it matters if we lower the thermostat in winter and raise it a bit in summer, but there are soon limits to how far you can go with that. The problem has always been that the building envelope is the weakest point and we have a great preference for letting the light in and windows are the poorest insulators. Typically, we have focused on insulation as the best line of attack to achieve better energy efficiency, but it may well be that we have overlooked other solution paths. The time to catch up is here, there are ways to block heat out or in, that may be more conducive to retrofitting than insulation. The case of replacement windows with double and triple glazing is infamous. Glass is a lousy insulator, and even two or three layers leave a lot to be desired. The R-values are roughly 1, 2, and 3 for single, double and triple glazing respectively, and that is assuming 1/2″ spacing in the double and triple glazing. Here is the solution:
From a recent installation
The installer packing up from his installation job.
In rough terms, with InFlector in operation the R-value improves 85% for single glazing, 80% for double glazing and still 75% for triple glazing. Immediately the next day, when there was a meeting, people noticed that this conference room was appreciably warmer than it was without these blinds.
In one report, Lawrence Livermore Labs estimated the payback to be between 2.5 and 4.5 years. Compare that to replacement window with a payback in the 12-20 year range. In short, if your facade is strucurally sound, no need to replace windows, just use InFlector. Besides keeping the heat in or out based on high emissivity, there is also a dead air space between the windows and the InFlector, which does provide insulation. One way of looking at it is that in winter, on the sunny side, the heat gain from a 4’x4′ area of window around midday is equivalent to putting a 600 Watt electric heater in the room, and because the reflective side is in, the room will retain the heat for a very long time. the overall effect is a 20-40% reduction in the thermal load of a building. Lastly, these shades improve your privacy, even though you can easily see outside.
This Installation was performed by Exquisite Contractors of Bridgeport.