Both U-Value and R-Value measure energy efficiency. Here are the main differences in a nutshell:
U-Value (also known as the U-factor) is a measure of heat transfer (heat gain or loss through glass), while R-Value is a measure of heat resistance. U-value is not a material rating; it is a calculation of the conduction properties of various materials used in the construction of windows, doors and skylights.
R-Value measures the performance of a specific material, such as insulation, based on the material’s ability to reduce the transfer of heat.
U-Value is a scientific calculation that measures the rate at which heat flows through 1 square foot of material; it measures how well a product keeps heat from escaping a building or home. The lower the U-factor of a window, the better it is at reducing heat transfer; that is, less heat will be lost. The U-factor refers to the energy efficiency of the entire window assembly, less, it is considered to be energy efficient. U-factor performance is especially important in how it impacts energy efficiency during the winter heating season in colder climates.
R-Value, on the other hand, is a material property value: It measures a material’s resistance to heat flow, which is important in the rating of insulation used in your windows, for example. It measures the rate at which heat is transferred or lost and is based on conduction and resistance. A high R-value indicates better insulation and resistance to heat transference.
R-value (also known as the R-factor) is relevant in terms of window blind insulation used to cover the window’s glass. The higher the R-value of any material, the greater the insulating value. It’s important to understand that when it comes to windows, U-value takes more than conduction of heat into consideration. It also considers airflow or convection around the window and the amount of radiated or reflected heat off the glass.
Triple Pane Windows Have Lower R-Value & Cost 300% More
Triple Pane Windows have a maximum R-Value of 5 and cost $350 to $650, plus $100 for installation per window. Insulated Window Blinds have an R-Value of 6 or 13 and start at $150 per window including installation.
Energy Efficient Triple Pane Windows Have Maximum R-Value of 5
2″ Insulated Window Blinds Offer a 690% Improvement
Per the chart below, it is clear that Insulated Window Blinds cost less and have a higher R-Value, but when looking at the performance they will add to a single pane window the research statistics are very impressive. For someone on a budget, Insulated Window Blinds make protecting windows against heat and cold a very cost-effective option.
R-Value and U-Value Increases for Insulated Window Blinds
Our Insulated Window Blinds are basically the same as the Interior Sliding Shutters in this chart. Please note that they provide a 692% improvement, are easy to install and are approximately 333% more cost effective than installing triple pane windows.
Here is the R-Value chart from the insulated window foam manufacturer that we will be using. You can see that a 1.0″ thick foam board offers an R-Value of 6.0. A 2.0″ thick foam board offers an R-Value of 13.1.
New York City, New York – According to a recent finding published in the Buildings Energy Data Book, buildings consume approximately 40% of the nation’s energy. Approximately 56% of this energy is used for space heating and cooling as well as lighting applications, while 25% to 35% of this energy is wasted due to inefficient windows.
All of these factors are directly by the building envelope. In addition to other functions, successful building envelopes shield occupants from outside weather conditions, whether that be excessively hot temperatures in the summer or extremely cold temperatures in the winter, as well as provide a connection to the outside in terms of natural lighting and views.
One of the major challenges facing homeowners is the high capital cost associated with installing window upgrades. The cost of replacing all the windows in a residential building can be substantial. However, the energy savings associated with replacing windows with their higher efficiency counterparts is typically relatively small.
The payback period for replacing single pane windows with double pane windows can be as long as 50 years for cold climates. This payback period will also increases as the quality of the existing window increases. When double pane uncoated windows are replaced with triple pane windows with argon fill and a low-e coating, the payback period is typically around 100 years for cold climates.
Therefore, for most homeowners it is necessary to determine alternative, lower-cost methods of reducing heat flow through their windows.