jay_fillion I'm curious to know what you ended up doing with this project. We are doing a very similar one, looking at Anderson 400 series. I've also looked into Marvin, Pella, Jeld Wen, and Kolbe.

Are you sure you have Andersen windows to begin with? I was not aware of any situations where Caradco (now Jeld-Wen) was making anything for Andersen. It is likely that you just have the Caradco window. In terms of what you have in aggregate efficiency, it is probably about a R-Value of 1 - 1.25. If your existing windows where properly sealed, relatively airtight, and not rotting, there would be zero rationale from the standpoint of energy savings to replace them with new insulated unit. Just improving the R-value/U-Factor in that window from and R-1/1.5 to an R-4/5 would take decades to payback and any benefits for solar control could more cheaply be supplied via applied films. In terms of what we want for this region, you want the lowest U-Factor you can get in any application. Whether you are a triple pane candidate depends largely on whether or not you are okay with the slightly darker window. If you were wanting to take advantage of the passive solar, you could go with a standard 2-coat low-e on the South facing windows and leave the triple pane to the other elevations. In a coastal application, the larger impact on efficiency (if you are comparing two similarly outfitted windows with Low-e) is going to be on air-tightness. That applies to how the window was both installed and how tight the window is. When we talk to clients about windows, we usually stick to the 4 aspects of: - Thermal resistance (U-factor) - Air Tightness (Air infiltration) - Visible light (VT numbers and profile thickness) - Warranty Feel free to ping me with any other questions.

It is worth the money because the addition of a LowE coating can save upwards of 35% or better in a hot climate and upwards of 18% or better in a cold climate - all else being equal. Whoever said 6% in your climate is wrong. It is better because it will raise the interior temperature of the glass in your windows in the winter making the room more comfortable at lower actual temperatures thus enabling you to keep your thermostat lower in winter. And it will reduce or eliminate the potential for interior condensation on your windows as well during the winter...although this isn't really a major consideration in your climate. The differences between the 200 and 400 series are a lot more than just LowE coating. The LowE coating is an option on the 200's as well. To get a true comparison price the 200's with coating and use the difference between those and the 200 without to compute the price of the coating. The LowE2 coating will block both long wave and short wave IR energy from entering your home. This is significant in your climate. Short wave IR is primarily direct solar gain. Long wave IR is primarily the reflection of direct sunlight from the ground, walls, whatever else - and into your home. The 400 series also comes standard with a titanium dioxide coating on the exterior glass - which reacts with UV light to oxidize organic contaminants on the surface of the glass - making the windows much easier to clean (in fact, some companies call windows with this coating "self-cleaning") and with a factory-applied poly-film on the glass to protect it from scratches and contaminants during installation. And speaking of UV - the LowE2 coating blocks a significant portion of UV from passing thru your windows and fading and damaging your furnishings. LowE is a no-brainer. Never buy windows without it.'

Please tell me what other aspects that I "side-stepped"? You posted about IGU failures and I posted the warranties relative to that from Andersen and the manufacturer (Okna) that you reference in your link back to another forum. The 20 year or lifetime reference was something that you pointed out. What am I missing? Do you wish to read the entire warranty? Here it is: Vinyl Frame And Sash Members The vinyl extrusions and vinyl components used in the windows and doors are warranted to be free from defects that might result in blistering, peeling, flaking, corroding, and fading of the window or door for as long as you own your home. This war- ranty is fully transferable to the next homeowner.  Factory painted standard or custom colors are warranted for a period of ten years. Insulated Glass OKNA Windows Corp. warrants that the insulated glass units, including internal grids, will be free from obstruction between the glass, including film formation, including moisture on the internal glass surfaces caused by seal failure and including small marks, dust, and scratches. This Warranty is fully transferable to the next homeowner and covers glass imperfections as de- scribed in Federal Government Glass Specification DD-04516.  Condensation may occur on interior and exterior of windows as a natural result of humidity within the house or build- ing area and changes in outside/inside temperature. This does not indicate a manufacturing defect and would not be included in this Warranty. Hardware OKNA Windows Corp. warrants that the hardware shall remain in good operating condition, for as long as you own your home. Warranty on hardware is also fully transferable to the next homeowner.  Specified Metal hardware for coastal applications is limited to a ten year warranty. Exclusions and Limitations The following are excluded from coverage under this Warranty: A. Any damage caused by wind, hail, lightning or other acts of God, intentional acts, accidents, negligence, or exposure to harmful chemicals or pollutants. This warranty excludes damage related to harsh or corrosive cleaning products, application of paints ( non factory applied ), and uniform fading or color change due to weathering. B. Any damage or malfunction caused by improper handling or installation of the windows, or any damage to the windows or components of the windows caused by settlement or structural defects of the building in which they are installed. C. Any defect, malfunction or failure to perform, which has occurred because of unreasonable use, improper application or failure to perform reasonable or necessary mainte- nance - see section " Maintenance & Cleaning." D. Any window, which has been repaired or attempted to have been repaired or modified by any person other than an authorized representative of OKNA Windows Corp. E. OKNA Windows Corp. liability is limited solely and exclusively to repair or replace, at the discretion of OKNA Windows Corp. and under no circumstances will OKNA Windows Corp. be liable for incidental or consequential charges such as, but not limited to, labor cost for any purpose, inconvenience, damage, or injury to persons or to property or any other expense. Procedure And Conditions Of Warranty Remedy The Owner must notify the Dealer/Distributor within thirty days after the defect has first appeared. OKNA reserves the right to inspect any window or door that a warranty claim has been made. Such notification must contain the following: A � Name and Address of the Owner. B � Date of Installation. C � Description of the Defect. If a product meets requirements of this limited warranty, OKNA Windows will at its option, supply replacement parts or product. Labor or reinstallation costs are not covered by this limited warranty. Commercial Application OKNA products installed in a building operated as a multi-family dwelling or used for commercial purposes or rental properties such as schools, churches, apartment complexes, government owned structures, etc. will limit this Warranty to ten years. Product Changes OKNA Windows Corp. reserves the right to discontinue or change any of its products or the parts utilized in any of its products at its sole discretion. If any window product or component originally installed in the building is not available at the time of any claim by you under this Warranty, OKNA Windows Corp. reserves the right to substitute any other model or component as a replacement. During warranty period replacement parts will be supplied at no charge to dealer upon return of defective part. Maintenance & Cleaning A mild solution of household cleaner such as liquid dishwashing detergent may be used to clean windows. Do not use harsh abrasives. This Warranty shall be null and void if harmful solvents are used. You are referencing "pressure equalization" and I reference that in the other post that you made. What additional scientific developments do you think need to happen. Is the fenestration industry going to "UN-INVENT" the law of partial pressures? There is no development needed in "pressure equalization" just better and better sealants and gas impermeable sealants to whatever the inert gas fill is. Andersen learned a valuable lesson with this and did a fine job of warrantying items after the fact when it was discovered that their IGU were gas fill permeable but impermeable to the larger molecules of atmospheric air. There is not much science to develop here. While vacuum IGUs are interesting and exciting developments, they are several years away from reaching mass distribution and acceptance. If you think that gas permeability presents challenges, vacuum presents far more challenges. Temperature shifts do present sealing issues to IGUs but if we can make sure the windows inside pressurized airplanes and vehicles that go outside the earth's atmosphere stay together, something in Desert Valley doesn't seem that tough. In applications where windows go above a certain altitude, breather tubes are inserted for equalization if they are not made near said altitude. The are certain aspects of the window industry that are pretty tried and true and I am not sure you layman's review of their cycle testing is accurate or based in any observable fact. I have been through several factory were they life cycle test these materials and they are comprehensive to say the least. No laboratory can ever truly duplicate a real world environment but they compensate for this most times by making the extremes more extreme to simulate worst case scenarios. The engineers at Pella, Andersen, and Cardinal would probably take umbrage with your less than factually vetted review of their testing and materials developments. Do they have failure rates, surely. This is why you get a warranty. Even in those situations where materials are manufacturer robotically, there is a human hand and potential for error at any number of locations in the process.