Thanks, mooring_girl, for the feedback on JeldWen. I should have realized that aging paint on fiberglass would be an issue. The big question is whether any of the factory finishes will look decent with our house paint, since the deck is at the front of the house, not the more private back side. We will have to wait to see the dealer's finish samples. ajm51, we live on the Monterey Peninsula, never too hot or too cold, and no air conditioning, so a sweating metal-clad door shouldn't be an issue.

Good golly Miss Molly, I did not say that rest of the unit is immaterial. I only stated that the OA glass unit, and the the Low-e selected is a very big component of the overall effectivness of the the unit. Millworkman, you are absolutely right about the aspect of a poorly constructed window. As regards to adequate weatherstrip, I've got my opinions on that one too. Most window companies that manufacture easy-tilt windows use "finseal" weatherstripping. This is a "woolpile" with a thin film of plastic designed into the pile to stop air infiltration. Most window companies have two rows of the "woolpile" designed into the systems. Premium window companies have three rows of this weatherstripping. A lot of other systems rely on a jambliner with a foam backing to "press" the jambliner against the sashes. This system makes the window easier to install because the window can be slightly "out of square" and still perform adequately. The problem, for a consumer standpoint of these systems, is that the sashes are more difficult to tilt-in. The "Achilles heal" that many companies have is the sill tower. Many companies do not have "finseal" designed into the sill tower, which can cause massive air leakage. As far as whether or not 0.29 is a good U-value: hey, shop and compare. I'll say this, I've seen a lot of numbers out there and there is a lot of distortion out there. Numbers can be manipulated by the size of the unit tested. I've seen it, I've personally been to the testing labs and I know what some people are doing. A lot of the purchase decision is going to made by the reputation of the manuacturer as well as the reputation of the distributor. OK, now about materials: *Is wood a good insulator: yes. *Is vinyl a good insulator: yes. *Is fiberglass a good insulator: yes. *Is non-thermally broken windows good insulators: NO. *Is thermally broken aluminum windows good insulators: Somewhat Regarding the differences between the energy efficiency of wood vs vinyl, the differences are marginal. To millworkmans point, the quality of the manufacturing plays a big role into the overall efficency of any window.

I'd recommend looking at JELDWEN's Siteline EX product. I used to sell Marvin's for years and still do once in awhile. In my area, I sell almost 7 figures a year in JELDWEN windows. I can say that their quality is near Marvin's and is 30% less. They also have a color called "Artic Silver" which looks like clear anodized but is an applied finish. Anodized coating SUCK as they scratch easily and cannot be touched up. If you don't believe me, ask your dealer what they warranty is on anodized product. If they don't say 5 years or less, ask for it writing prior to ordering. Artic Silver is a 10 year warranty through JELDWEN(20 years if you look at their Custom series product, which is equal to Marvin). As for Hurd, if they're close to the same price as Marvin I would pick the Marvin if you're not interested in JELDWEN. Hurd is a crappy brand name and what's the point of buying "knock offs" if there's not enough savings to justify it? I don't go to the flea market and expect to pay 10% less. My advice, look at JELDWEN's Siteline EX product. If you don't like the quality, buy Marvin. Find a GOOD dealer in your area that knows what he's doing and you feel you can work with. Call the manufacturer and see who they prefer in your area(they'll give you their best dealer who buys the best). Lastly, remember pricing isn't everything. One mistake can easily suck out what you saved by "shopping around"...

I use all three types you mentioned: aluminum clad, vinyl, and fiberglass (actually the Fibrex you mentioned is none of the above - it is a wood/vinyl composite material but not as strong as fiberglass). All three are designed to last a long time, but they have their differences. And to answer your question of "Why do these [fiberglass] windows break down faster than a vinyl one" the answer is "They don't!" I'll briefly touch upon the three types. WOOD/ALUMINUM CLAD This is actually my favorite type. Wood windows are strong, they're great insulators, they're aesthetically attractive, and the exterior can be clad with aluminum so that the only maintenance needed is washing the windows. Disadvantages include that it is usually the costliest of the three types being discussed, and it requires painting/staining on the interior side (unless you order them prefinished). Of course those could also be interpreted as advantages. Another potential disadvantage is that if the windows aren't efficient enough to handle the existing conditions, condensation could cause the wood to discolor and even rot. However, modern wood windows are preservative treated before they leave the factory, and more and more are changing to lifetime warranties on the wood. There are different qualities of wood windows, and generally speaking the better ones will last longer than the low-end ones. Some have service departments that make house calls, and some have no service departments at all. VINYL Vinyl windows sometimes last longer than wood windows, sometimes less. Like wood windows, there are varying qualities and longevities. Not only are there different qualities of weatherstrip, glass, and structural integrity, there are different qualities of the actual vinyl itself. Some will change color or turn more brittle than others (but they are all a lot better than vinyl products of 25 years ago). Wood and fiberglass window manufacturers are quick to point out how much stronger their material is compared to vinyl, which is true, but you're not buying a slab of wood or fiberglass; you're buying an entire window unit. Vinyl windows, if properly designed, will last just as long as fiberglass and wood. Fiberglass and wood windows are more impact resistant, and have less expansion/contraction, are more scratch resistant, and are stronger/stiffer than vinyl windows, but vinyl windows if properly used don't need to be as strong. How impact resistant does a window need to be? How stiff? Vinyl is just fine for it's intended purpose. I envision vinyl windows being mainly utilized in single and double openings. In new construction, where one might have 4 windows wide by 3 windows high - a wall of glass - I wouldn't use vinyl because it has a lot more flex, and that deflection under a heavy wind load could lead to air and water infiltration. It just can't meet the performance criteria of the others. But that's an extreme case. And even vinyl can come with metal reinforcements inside to make them stiffer. Aesthetically, vinyl can be some of the ugliest windows available, and it can also look quite appropriate, depending on the brand. But beauty is in the eye of the beholder . . . Vinyl window companies usually have superior warranties compared to wood and fiberglass window companies, but it's not indicative of the windows being any better or lasting longer. Here's the catch. Wood window companies usually have a warranty that applies to whomever owns the home. Vinyl companies usually have a lifetime warranty that applies to the first homeowner only. Since people usually move on average every 8 years (at least that's what it used to be; I haven't seen any stats in the last few years), that equates to an 8 year warranty. Most have a transferable warranty program, but the warranty can then be reduced from "lifetime" to perhaps 10 years, and only if you fill out a transfer of warranty form within a certain amount of time, and possibly submit a transfer/filing fee (sometimes for quite a bit of $). So some of the advantages of vinyl windows would be affordability (usually but not always), low maintenance, and very good performance (for the better brands) in medium to small openings (that's my opinion). FIBERGLASS There are not as many fiberglass windows companies out there (so far), some of the largest being Pella, Marvin, Comfortline, and Milgard. There is also the Andersen Renewal window, with its Fibrex product it is not fiberglass but instead is a wood/vinyl composite. Fiberglass windows combine some of the advantages of both wood and vinyl. They're stronger than wood or vinyl, have less deflection/flex than vinyl, are more impact resistant, do not require painting/staining, usually cost somewhere between vinyl and wood, have less expansion/contraction than the others, can not rot, and can be painted over in case you want a different color (for example on the inside of the home). Unlike vinyl windows, wood and fiberglass windows are mechanically fastened (which is neither good nor bad, that's just the way they must be made. They don't need welding and can not be welded). As for the Fibrex window from Andersen, I've heard good and bad (like I have with most brands), but have never worked with it and have not closely observed it. Seems OK to me but I don't like their negative selling approach where they slam wood and vinyl. It's backed by a respectable company (Andersen) with deep pockets. So fiberglass, vinyl, aluminum clad - take your pick. The better brands (assuming properly installed) will perform just fine in all three categories. They have different warranties, some have better service departments, some look better than others, some are better suited for some types of projects than others. It's good to look at not only warranties, options, and aesthetics, but also at performance statistics: U value, design pressure rating, solar heat gain, air infiltration, etc. Again keep in mind you're buying an entire window unit, that has many parts/pieces that are designed to work together - one should not base their decision on just looking at the frame and sash material only (aluminum clad, vinyl, fiberglass). I have Pella windows and Marvin windows in my house - two of the higher end windows around. Both have performed flawlessly and I'm very satisfied with both.