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Ecological Windows

A window should be looked at first as a tool and second as something adding aesthetic value, not the other way around.

Insulated Windows

This window on the Lotan tea house is doubled paned, aluminum framed and well sealed.

Heat moves from a hot place to a cold place.  Heat is transferred both through solid materials and though moving air.  Insulated windows reduce the transfer of heat because of the seals, the frame and how the layers of glass are constructed.

Insulated windows have excellent seals between the window and the wall as well as between the moving elements of the window.

High performance window frames are made from materials that have low conductivity.  Metal conducts heat quickly so metal frames are hollow and have interior insulation that separate between the interior and exterior facing sides of the frame.

Double paned and made from materials with low conduction properties makes this window well insulated.

Heat moves quickly through glass. Insulated windows have two or three layers of glass separated by air, argon gas or a vacuum (which is the most efficient). 

Low-E coatings allow a full spectrum of light into the house but reflect infrared which can not be seen but is felt as heat.  In cold climates it returns outgoing heat in passive solar houses at night and in hot climates reduces heat gain during the day.

Exterior Blinds

Exterior blinds are excellent compliments to insulated windows when passively solar heating and cooling

Shutters on the windows of the domes in the Lotan EcoCampus keep the hot desert sun out of the domes during the day, keeping them cool even in the hottest parts of summer.

In the summer and on hot days in the spring and fall, exterior blinds protect windows from exposure to the sun, keeping the room from heating up.  In regions with hot days and cool nights, passive solar houses with exterior blinds kept closed during daylight hours and avoid use of air conditioners.

In the winter exterior blinds reduce the loss of heat through windows exacerbated by cold winds passing along the glass.  Also, closing the blinds stops loss heat from radiation through the glass (a better technique is to use a curtain or interior blind).


Contact Lotan Center for Creative Ecology
Tel: +972 8 6356935; +972 54 9799030
Toll free (while in Israel): 1800 2000 75

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