A Window that will Heat and Cool Your Home: KSD Solar Window

From ÖKO-Logic in Germany comes a well insulated window that spins to allow you to set it with the seasons. In the winter setting it accepts 70% of the sun's heat. In the summer setting it reduces penetration of the sun's heat producing rays by 70%.

Not only is this window efficient, it can be switched from a winter position in which it gains heat to a summer position in which it rejects heat.

The KSD window has six layers: white glass, SZR with argon gas, low-E-coat, float glass, Foil and green glass. In the winter the green glass layer is on the inside. In the summer it is on the outside.

The window has been available for some time in Germany, but I could not determine whether the company they set up to bring it to the USA, Eco-Logical Innovations, has been able to set up distributors yet.  (04/2011  Links to  distributor appear dead.  Here is a link to a mostly English brochure for the window produced in 2007.)

	Winter Position		Summer Position
Air temperature Fahrenheit	Outside = 32	Inside = 68	Outside = 32	Inside = 68
Sun energy (Watt per square meter)	Temp. outside window pane Fahrenheit	Temp. inside window pane Fahrenheit	Temp. outside window pane Fahrenheit	Temp. inside window pane Fahrenheit
0	34.34	61.34	69.62	68.36
100*	35.96	70.34	74.66	69.62
300	37.94	85.46	84.2	71.96
500	40.28	98.60	98.6	74.3
700	42.62	110.84	102.92	77

* Example: Already at 100 watts of solar energy in the winter time (cloudy sky) and at outside temperature of 32 degrees Fahrenheit, the inside window pane heats up to over 70 degrees. As a result a thermal barrier is created and no energy is lost through the window, effectively reaching a U rating of zero.

The video below features a demonstration of the window at a European trade show.