Some Online Resources

[David MacLeod]

American Council for an Energy Efficient Economy: Consumer Guide to Home Energy Savings
http://www.aceee.org/consumerguide/

Home Energy Saver
http://hes.lbl.gov/consumer/

Home Energy Magazine
http://www.homeenergy.org

Home Energy Magazine Consumer Information Section
http://www.homeenergy.org/consumerinfo/

When to Replace your Refrigerator
Here's a section at Home Energy that helps you determine whether it makes sense for you to replace your refer with a more efficient model.
http://www.homeenergy.org/consumerinfo/refrigeration2.php

It offers a database where you can look up your refrigerator and determine its Energy Efficiency rating.
http://www.homeenergy.org/consumerinfo/refrigeration2/refmods.html

Then it offers a calculator to determine if yours is worth replacing (based on cost savings, and not including consideration of the embodied energy that would have to be replaced when you purchase new and recycle the old).
http://www.homeenergy.org/consumerinfo/refrigeration2/rsearch.php

[Ehben Eliot]

As it turns out, "consideration of the embodied energy that would have to be replaced when you purchase new and recycle the old" is an important consideration. While the actual amount of energy embodied in a replacement item can be extremely difficult to calculate, that amount is likely signifigant.

When performing a calculation for which a certain variable is unknown, it is often better to insert a hypothetical value, rather than to leave it out completely. Furthermore, one should postulate on the side of safety. In many cases, it would not be unreasonable to assume that the new appliance is composed ENTIRELY of energy.

When considering a replacement scenario for which detailed information is lacking, ask yourself "is the cost of execution less than the cost of the energy saved?" Don't forget to include the 'hidden cost of energy', but that is another story.

[David MacLeod]

Here's another article on choosing an efficient refrigerator

It's a good article, but again, it doesn't include consideration of the embodied energy of the new unit, nor the paypack time.  It does discuss a comparison that shows it to be a better investment to buy an efficient fridge over buying a solar panel.