BEST
        
CUSTOM WOOD SHUTTER: A good quality shutter panel, when closed, creates a heat barrier that will perform statisfactorily even in the worst window scenario. The thickness of solid wood is a great natural insulator.

SOLID VINYL PVC VERTICAL OR HORIZONTAL: This product in a light color will form a great reflective surface, plus the inherent tendencies of PVC help create a tremendous heat reduction. PVC absorbs a large amount of heat then releases it slowly into the room.

VINYL COATED BLOCKOUT ROLLER SHADES: This solid layer of vinyl coated fabric has no light or air gaps, therefore it reflects most heat gain before it even enters the room.

TOTAL BLOCKOUT CELLULAR SHADES: The reflective Mylar lining inside a blackout cellular shade adds to an already effective cellular fabric layer. The white exterior color of the shade helps reflect heat before it enters the room, and the air layer inside the cells slow down heat transfer into the room.

BETTER

DOUBLE CELL ROOM DARKENING: Extra heavy fabric woven in a double-cell layer insulates very well. The lack of a Mylar lining is all that keeps this from being in the top category.

2" WOOD BLINDS: The combination of light color reflectivity and real wood composition creates a very effective treatment. 2" wood blind slats are only 1/8" thick, so they cannot insulate as well as custom wood shutters, but they are still very effective.

DOUBLECELL, OPAQUE SHADES: Still a very good insulator but the thinner fabric drops it below the rating of the Room Darkening fabric.

SINGLECELL OPAQUE SHADES: Very good insulation qualities, but maybe 5-7% under the Doublecell construction.

ALUMINUM HORIZONTAL BLINDS: A metallic or light color aluminum slat is a fairly good heat reflector, but Aluminum absorbs and re-radiates heat fairly rapidly. Only use in situations where direct sun is not a problem, or where a high quality tinted glass is present.

GOOD

FABRIC VERTICAL BLINDS: Fabric louvers alone will not insulate as well as PVC. The more sheer your fabric choice, the lower the value will be. Some of the heavier lined fabrics do rate farily well. Because of the large variety of fabrics, it is hard to rate the product in a single category.

VIENNA FABRIC SHADES: While these are beautiful treatments, the light sheer construction keeps this product from being a great insulator. When the privacy slats are closed, the insulation value is adequate unless there is a severe sun or heat problem prosent.