Which is better - uPVC or Aluminum Windows

Until 20 years ago over 50% of homes in the USA were fitted with aluminum frame windows. Now that figure has drastically changed. Over 50% of homes in the USA are fitted with uPVC windows. So why has aluminum become so unpopular?

The reason lies with thermal resistance. uPVC windows increase energy efficiency in a home by increasing insulation. uPVC windows provide a good thermal barrier between inside and outside. In the winter uPVC windows with double glazing keep the cold out and the heat in; and in the winter, they keep out the heat and keep in the cool. By insulating your roof space and by installing uPVC windows and double glazing you can make big savings on your energy bills. It is estimated that one uPVC window will save you $20 in one winter in heating bills.

Aluminum on the other hand is a metal and a ready conductor that absorbs and gives out heat and cold very easily. Aluminum windows cost about the same as uPVC windows and both types cost less than good timber frame windows, and so it is not surprising that uPVC has taken the lion’s share of the market in windows.

However, aluminum is not without its benefits. It is lightweight and very weather resistant. Aluminum windows can outlast uPVC. Also unless uPVC is reinforced with metal it can seem a bit flimsy, especially for French doors and patio doors. Although you can easily dent thin aluminum it is a strong metal that is hard to cut. Well installed aluminum windows can provide better security than uPVC windows. Of course, if the uPVC frames have double glazing and multi-point locking systems then uPVC windows are just as secure as aluminum widows.

An advantage of aluminum windows is that they take up less visual space. uPVC tends to need a clearance of 10 to 15cms on both sides of a wall, whereas aluminum windows fit in just a few cms of wall space. This means less window material is blocking the sunlight with aluminum windows than with uPVC windows.

Another point in aluminum window’s favour is that modern aluminum windows often come with thermal breaks that increase the thermal resistance of the windows. Not in line with uPVC but still it represents a money saving.

The real saving, however, might be made in environmental terms. Aluminum is not a carbon friendly material if you factor in the costs for mining, manufacturing and transporting the metal. It does seem, nevertheless, the lesser of two evils. uPVC is a petroleum based product that gives off noxious and life threatening fumes when burnt. It is notoriously hard to either safely ‘neutralize’ or recycle uPVC and PVC waste. Changing World Technologies have apparently pioneered a method to convert uPVC and other plastics into crude oil but so far they have only one factory. People are far from convinced that Changing World Technologies is going to do that just that – change the world. The fact is that uPVC mostly winds up at a land fill site and these land fill sites often have fires which release carcinogenic dioxin fumes into the air.

It’s a lot to think about.