Reflective materials restrict heat flow

I would like more details on millium, a shower curtain of aluminum-coated fabric, and energy-saving window shades. Is millium the same as a space blanket? Fernand Bartlett Syracuse, N.Y.

Millium is an aluminized lining material which is used in clothing, draperies , etc., to inhibit the passage of heat and cold. In other words, it is a reflective material.

If you take a piece of tinfoil and press your finger against it, you can feel the warmth of your own finger.This is what millium does. It would seem reasonable to believe that if a sheet of millium were placed on top of a mattress, it would keep a lot of the body heat from escaping into the mattress.

There are other competing products, such as Roc-Lon, which are used for their insulating properties in draperies, and the like. The Space Blanket is made by Durofab, I believe. I would imagine the properties and performance are similar.

There are many energy-saving drapes on the market but they're not cheap in price.

A company in Lenoir City, Tenn., sells what is called a Window Blanket. It has a cotton facing, insulated lining of Roc-Lon, and polyester filling that is similar to a sleeping bag. Another product, called the Window Quilt, is made by the Appropriate Technology Corporation of Brattleboro, VT. The insulating Shade Company of Guilford, Conn., makes what it calls the High "R" Shade. There are others as well.

The Window Blanket, which comes in a standard 45X84-inch size, cost under $3 a square foot while the Window quilt is priced at $4.25 a square foot.

They're all designed to reduce heating costs by reducing air infiltration into a room.

I'd check in a large department store or mail-order catalog for aluminum-coated shower curtains.