R-Values of Wood Shutters and Blinds

According to SmartEnergy Living, "Hardwood shutters and wood blinds offer R-values between 2.77 and 3.17 and a shading co-efficient between 0.35 and 0.21."

Hardwood shutters figure to be on the higher end and blinds on the lower end.

Also, "Window treatments add another important benefit aside from insulation - UV protection. UV rays can damage your home's interior, including furnishings, artwork and heirlooms, and floors."

Definitions of R-value and shading co-efficient per www.wikipedia.com and Bendheim Wall Systems:

R-value is a term predominantly used in the building industry to describe the insulation properties of certain building insulation materials. Its use is limited to situations where thermal insulation is achieved by retarding the flow of heat through the material itself rather than reflecting radiant heat away. The higher the R-value, the greater the insulation. Although they offer a useful means of comparing the performance of different products, other factors need to be considered in maintaining thermal comfort.

The shading coefficient is the ratio of solar energy that passes through a piece of glass relative to piece of 1/8” clear glass ( which has a shading coefficient of 1.0). Solar heat gain coefficient represents the solar gain through the glass relative to the incident solar radiation; it is equal to 86% of the shading coefficient. In either case, a lower number indicates improved solar control over the 1/8” clear glass baseline.