The argument that one spacer system is inherently superior to another or all others  is ripe with the possibility of misinformation, misunderstanding, and certainly a great deal of emotionalism. Each system has its proponents and its detractors. SuperSpacer uses an organic as the primary moisture and gas seal. It uses an acrylic as the primary structural seal. Unlike other systems, SS is "backwards" in that it places the structural seal inside of the moisture seal. The primary structural component of SuperSpacer is silicone - which is neither moisture nor vapor resistant, so the silicone is wrapped with a moisture barrier to prevent air and other gasses from passing thru the silicone. Does this make SS an inferior product? Nope, not in the leastÂactually SS outperforms every other system on the market in energy performance numbers. What EdgeTech (makers of SS) does really well is market their product (for example "Health Smart Windows" is primarily a marketing tool). They have what may be an excellent product, but they also have a marketing program that totally kicks butt! They have opened areas of discussion that really didnÂt exist prior to their introduction of itÂthey have emphasized SSÂs inherent advantages while ignoring any potential disadvantages (which is what marketing folks do, of course). They have "invented" new ways to categorize window spacer systemsÂheck, they have introduced IGU spacers to the general public. For an example of longevity, EdgeTech advertises that their system goes 80+ weeks in a P1 test chamber (a standard for testing dual pane windows). They advertise that the "Stainless Steel" systems go 40+ weeks in the P1 chamber. What they donÂt advertise is exactly how long is the "plus" in the 40+ weeks of the "metallic" systemsÂhow about 80 weeks for a PIB / silicone dual seal stainless steel spacer system. By the way, at 80 weeks or so the glass begins to break down and the seal tends to be lost at that point because of glass rather than spacer issues. The hot melt systems used with the SuperSpacer system also have a very specific application temperature range of about 275º  325º. If the applied material is outside of this range, then the P1 chamber testing can be significantly reduced  to as little as two to three weeks to seal failure. What happens in the field in this case? Only time will tell. Am I slamming SuperSpacer? Nope, not a bit. When manufactured to strict quality control standards and exactly as specified by the manufacturer, then SuperSpacer really is a very good, even superior, product. Energy performance and durability are what these things are ultimately about. How do different systems compare? As I mentioned, SuperSpacer is on top  at the edgeÂand TPS is second, by about ½ of a degree or so. The Stainless Steel systems (there are a couple of different ones) tend to be about a degree or so lower  about equal to Swiggle (again, at the edgeÂthe difference may not have much of an impact on the overall U value depending on the construction of the window). Drop another degree or so to Intercept and about another 8º for an aluminum spacer. Using a LowE coating will have more of an effect on the overall window temperature than does the choice of one of the "warm edge" systems. Of course using a LowE coating with SuperSpacer and with Swiggle still keeps SS a couple of degrees warmer at the edge. BUT, these are also ratings of the "raw" IGUÂwhat happens when the unit is in a frame? Well, how about this for thought: Conclusion The thermal resistance of the spacer bar material influences the glass temperature at the edge-of-glass region of an IG unit. Based on the limited testing performed at IRC and computer modelling at EMPA Switzerland, the spacer bar with the highest thermal resistance shows the warmest glass temperature on the warm side and the coldest temperature on the cold side of the glass at a distance 5 to 60 mm from the edge of the IG unit. But the effect of the type of spacer bar on the overall thermal resistance (and tote heat loss) through windows depends heavily on the window design and material. Therefore, the full impact of thermal characteristics of the spacer bar material on the thermal resistance and the condensation resistance of a window should only be determined by testing complete window assemblies. Interesting concept  testing complete systems.

Carol, I do apologize if I was mistaken. If you read these boards enough, you'll notice that 9 out of 10 posters that pop up with very glowing posts about a company that had not even been part of the discussion are SPAM, and usually company reps dishonestly posing as consumers. In addition, you offered some inaccurate information in your posts including generalizations about the thickness of vinyl vs fiberglass, performance factors etc. Just to address a couple of those, a high quality narrow line vinyl product like Sunrise or Okna will offer a very similar "edge of frame to glass" measurement as a fiberglass alternative. In addition, the thermal and structural performance of those vinyl offerings will meet or exceed those fiberglass units, and in some cases like the Marvin, they blow it out of the water. The Inline otoh, offers very good performance which is comparable to the vinyl options. I am not familiar with the Fibertec or Thermotech. I would also add that the expansion/contraction issue is dramatically overstated. Empirical evidence shows that the differences in a residential window application are basically negligible, and in addition, the properties of the base material for any given product are most certainly taken into consideration in the engineering of the product, and thereby mitigating any potential negatives. All that said, I am not just a vinyl "fanboy" despite my defense here, it just happens to be a material much that is maligned by misinformation put out by folks wanting to sell alternatives... as well as by the fact that there are just way too many lower end vinyl products out there that give the material itself a bad name. Ultimately, as I have stated earlier in this thread and in many others, each material has its own pros and cons, and each can be the "best" choice in a given application. Lastly, once again, please accept my apology if you were just sharing your personal experience. Perhaps the differences in perception have something to do with the products that are available in the US versus those in Canada.

If you are referring to combining vinyl windows and fiberglass doors its done all the time. Simonton is a good solid product but for replacement I would not consider the ProFinish and step up to the Grand Estates Premier (equivalent to the Simonton Reflections 5500) or the Grand Estates Premium Plus (equivalent to the Simonton Impressions 9800) The ProFinish Line is Simonton's new construction window with catalog sizes its not built at the same quality level of the above listed products. within the ProFinish Line the Brickmould 600 is the best one but again not as good as the above.

If you are looking at the narrower side of the spectrum in terms of vinyl, the glass loss will be negligible. Do you have storm windows? If so, a narrow profile window will likely fell larger.