Understanding Energy Efficiency Ratings
Whether or not you are concerned about the environment or about our diminishing supplies of natural resources, we can all agree on the concept of saving money. When shopping for new appliances, I am sure that you have seen the Energy Star efficiency ratings posted on products, but do you know what they really mean?
Energy Star ratings are a good basis for understanding energy efficiency, but they are based upon model type.
The first thing that you need to know about Energy Star ratings is that they are based upon an average rating for the product type. A Federal Standard Kilowatt per Year in energy usage is determined for the product type and for the different sizes and styles of the products. For example, all toaster ovens are compared and the average power consumption becomes the base line for the ovens on a whole. Products that are more than 10% to 20% more energy efficient than the Federal Standard for energy usage get an Energy Star rating.
The second and most important thing that you need to understand about Energy Star ratings is that they are based upon similar models, not products on a whole. Refrigerators are a good example of this. You must compare the Energy Star ratings of similar models. Side-by-Side fridges are the least efficient of all fridge models with an average Federal Standard k/Wh/Year rating around 725. The average Federal Standard k/Wh/Year for bottom freezer models is around 689. For standard top freezer models the Federal Standard is 466. I arrived at these numbers by averaging 10 different models of each type from the data on the Energy Star website.
If you go shopping for a new fridge and want to buy the most efficient model, you must realize that buying a Side-by-Side that is Energy Star rated as being 20% more efficient is actually going to consume more power than a top freezer model that is not Energy Star rated. An Energy Star rated top freezer refrigerator can actually consume around half of the energy per year of a standard rated Side-by-Side and about a quarter less than an Energy Star rated Side-by-Side.
Energy Star ratings are submitted by the companies that produce the items. This may make you question there validity. However, the requirements for getting an Energy Star rating require that the results must be easily validated and repeated. Many different consumer advocate groups follow up the reported results with their own independent tests.
Energy Star ratings are a good start for any consumer wanting to reduce energy consumption or costs, but you must do a little research and understand the different model types that are being compared. Check out other consumer websites that can provide actual user feedback on the different models.