Most warranties like this are designed as sales tools to fool the customer into thinking he is getting a better window than he actually is and to convice a buyer the additional 50% savings will help offset the cost of usually overpriced windows. Here's how it works.

Typically to file a claim, the company requires that YOU prove to THEM that you did not save 50%. (you will never be able to actually do this)

The guarantee requires you to submit all of your utility bill for the 12 month period before the windows were installed and the 12 month period after the installation. No bill, no warranty.

Then you are required to submit a reciept that you had your furnace and air conditioning serviced by a licenced contractor.

If you are able to do this, they will then require you to calculate the differences in heating degree days with an hourly comparison of the temperature difference between the exact date in the 12 months before the install to the 12 months after the install. This of course is quite tedious if not impossible to do.

If you are able to submit undeniable documentation that meets with their approval to all of the above (I may be missing a couple of additional requirements) they will take the difference between what you are able to prove you saved, say 40% and the 50% claimed in the warranty = 10% and they will pay you the difference.

So, if in the 12 months prior to the installation your utility bills were $3000 and instead of saving $1500 you only saved $1200, they would only be required to pay you $300. The energy savings pledge has a maximum cap on it of $500 and can only be claimed once within the first year after the installation.

Quite an elaborate little con to get a buyer to purchased overpriced window, eh?

I don't know what window Long Fence is selling now that their supplier, Kensigton windows went bankrupt. The Quantum 2 Window was a pretty good window but Long Fence was selling it at about 30% more than it was really worth. Kensigton has been purchased by Serious materials and it may be the are making the window again.

If you are a fan of the Used Car Salesman approach, you will be in hog heaven if you schedule an appointment with them.

Like Sky said, they used to install a pretty good window, nothing special and nothing that can't be bested by half a dozen other windows out there, but were grossly overpriced and use alot of sales gimmicks.