Low-E ideally works to reflect the ultraviolet rays, reject infrared and keep your home cooler in a warmer climate. Argon gas is an injected gas between the Panes of glass to help prevent cool air from penetrating in the winter. Argon gas is typically warranted in a colder climate. A simple rule of thumb is Low-E is and should be standard in a southern, warm climate, and argon gas should be standard in a colder climate. With all of that being said, it's become truly unfortunate and a market only for the extremely savvy. For those of you that are under the impression that you can purchase windows and feel confident in your decision without a hitch, you're likely in for a rude awakening. Many,many scam are perpetrated daily. Many examples, but I'll try to stick to the topic. (Low-E), many companies claim that theirs is better than another companies. How so? Well, they claim their application and product performance is better. What I've found repeatedly without fail is that they'll sell the consumer on something that sounds great, Low-E squared, or Low-E cubed, and it's passed off as better, because it rejects more heat. But in reality it's the equivalent of a rushed painting project. No one would ever paint an interior wall by applying 3 or 4 coats at once. You sand, prime, then apply your base coat until you're satisfied with how it's turned out. That's exactly the gimmick behind low-e squared and cubed that companies like Milgard use. On to Argon Gas, is it necessary even in a cold climate? Sure, but only if you're truly getting a iron clad warranty on the stabilization and life of the argon gas. How it's injected, stabilized and where it's manufactured are all key. In Denver, CO, or Minnesota, which is where Andersen Windows manufacturers and ships, let's say that you live in Phoenix, AZ, like I do. You will see in the fine print, if you look; that they guarantee the presence of 99.9% of argon gas upon manufacturing. That 99.9% goes all the way down to a worthless 5%-0.1% upon installation. So, what are you really paying for?
In summation, it's become extremely difficult to pick the right product from the wrong and to identify the good companies from the bad. So much so that you truly need help with this process. It's not dissimilar to buying a used car. Consult a knowledgeable friend, confidant or professional before purchasing any type of home improvement project.