It might sound odd, but you can now buy insulating paint that promises to keep your home warmer in the winter and cooler during the summer. Insulating paint is made with ceramic materials that block heat loss. When applied to walls, it looks like any other regular paint. Insulating paint is supposed to reflect heat back into the room instead of letting it pass through the walls. In an article on his website, Sensible Home, columnist and engineer James Dulley writes, "Another advantage of using ceramic insulating paint is the dried paint film on the walls is thicker than with standard non-ceramic paint. This tends to fill tiny cracks and imperfections in the wall surface similar to using a thick primer coat first."
A few insulating paints are made from aluminum particles. According to Dulley, this technology was developed by the military as a strategy against heat-seeking missiles. Ceramic insulating paint lowers the "emissivity of wall surfaces."
Insulating paints come in pre-mixed 1- and 5-gallon cans, but you can also purchase ceramic powder and mix it in with any standard interior paint. The paint goes on thicker than standard paint, and you need to use a little bit more of it. Because of the thicker coat, the paint lasts longer than noninsulating paint. When the paint dries, it forms a ceramic layer on the walls.
Hy-Tech (*Est. $30 per gallon) makes an insulating interior/exterior paint that is washable and stain-resistant. The interior paint, which is 100 percent acrylic, covers up to 300 square feet per gallon and dries in less than three hours. It is only available in a flat finish, and only in white, but you can add tints to customize the color. Another company, Insuladd, sells a white, 100 percent acrylic, interior/exterior insulating paint (*Est. $35 per gallon) in satin finish, or you can buy a pouch of its ceramic additive (*Est. $15) that you can add to a gallon of ordinary paint to make it an insulating paint.
Do insulating paints really help keep a room warmer? Dulley says they do, though he didn't measure the temperature in his sample room. The EPA says "there is no agreement on testing standards for paint or coating products regarding their energy saving performance or durability for use on walls." It does not certify any paints as energy savers under its Energy Star program, and it does not recommend relying on insulating paint rather than regular insulation.
Other reliable sources are wary of the value of insulating interior paint. "According to the Department of Energy's Oak Ridge National Laboratory, the use of so-called insulated paints is in most cases 'difficult to justify on the basis of savings in energy costs alone,'" says E, the Environmental Magazine. "Nevertheless, for certain applications, especially in concert with traditional forms of insulation underneath, insulating paint can help reduce energy expenditures and air conditioning bills accordingly… Adding insulating paint should merely be the icing on the cake of an otherwise well-conceived plan to cut heating and cooling costs." If you're interested in trying insulating paint, Insuladd and Hy-Tech are two of the brands the magazine mentions.