What IGU specs do you recommend for storm windows in Wash. State?
I have been reading the postings here and learning a great deal (especially from the Oberon postings which are very informative--you should write a book).
I recently bought a 1920's Craftsman house in the Pacific Northwest, about ten miles inland from the coast, near the Canadian border. Luckily, most of the original wood windows are still in-place (I don't care for new windows). I can't find much local, good glass advice.
I am planning on building some storm windows myself for winter use (and occasional hot days in the summers). I plan on using 1-1/4" square cedar for the frames (primed & painted) and routing out a dado channel for double-pane IGUs. My plan is to use silicone to thoroughly seal the glass in these channels and use a good neoprene foam tape all around the seal between the storms and the old windows. I know installation is critical.
I want to use double-pane, argon filled, LowE coated glass in these storm windows. I'm a little unclear though as to what the best specs would be for the glass? I also have no idea what to expect as to cost for the glass. Is there a rough ballpark per-square-foot estimate for the different types? I've searched online hoping to find a supplier of IGU's but I guess fragility and weight are the reasons you can't order an IGU online. I started at a big box and found they can order replacement double-panes (technically for one of their window products but I guess they will order even if you want it for something else) which were about $80. for a 55"x22" double-pane, argon with LowE (5/8" total thickness). I assume this is Cardinal glass that this company sells through the big box though they can't seem to tell me any more detailed specs than what I've written here.
Our winter temperatures are around 40's F (day) and 30's F (night) (though it can reach zero on rare occasions). The summer temps here are rarely hot though this year it got to 100 F on a few days. Currently, on very hot days, this house stays comfortably cool without air conditioning but during winter, it can become unbearably cold and cost hundreds in propane bills each month. I assume that means a "high" SHGC coating would be better so that I could get some passive solar benefit in the winter (even though the house may get a little warmer in the summer)? How do you communicate that you want a "high" SHGC or do the other specified variables determine the SHGC? What thickness of glass should I look for? What type of edge-spacer should I specify or is that not too important? Should the LowE be soft or hard coat? Can all these things be specified if I buy from a glass supplier?
I've called some wholesale glass shops that I'd love to do business with but they won't talk to me and instead send me to the small glass stores--none of the small shops I've talked to seem to know much.
Thanks very much for any advice.