What’s better use of $$$’s for energy efficiency improvement

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FPX Dude

FPX Dude

Feeling the Heat
Oct 4, 2007
481
Sacramento, CA
I have good attic insulation and pretty good air tight house due to improvements I've been making. My next venture is to provide better "insulation" against my windows. They say windows are 10–25% of a home’s exterior wall area, and account for 25–50% of the heating and cooling needs, depending on the climate (I'm in Sacramento). I currently have 20 yr. old plain 'ol dual-pane windows, with simple venitian blinds and single cell shades. In winter you can really feel the cold coming thru them and in summer I get direct South sun and I bake.

So, what would give me a better "bang for my buck", go with Plantation Shutters or replacing my window's with high efficiency loE/argon windows. Plantation shutter's which go for $17 sq. ft. installed, so for me that'll be $8k.
 
Better off with new windows IMHO.

Shawn
 
A radiant barrier in the attic is very inexpensive and you can install one yourself using a staple gun. Probably cost you less than $200. Put bubble wrap on the inside of your windows until you get them replaced.
 
I think the new windows would be the way to go. I have new Pella LowE Argon windows all around my main room it is a 24x30 and it has 6 - 6x6 windows in it and I can't feel heat in the summer or cold in the winter standing in front of any of them at all. I say they are worth the money for sure.
 
Def. new windows! I put Simonton casement with all the works in to replace 10 40 year old Anderson windows. The difference is HUGE! No more blowing curtains when the wind blows for me!
 
I can't find any pricing info on super wazoo triple pane loE/Argon windows on 'net yet, any ideas of price per square foot so I can compare to shutters ?
 
I recommend you gather a little more information:

Where exactly is the leakage in the windows? Perhaps a can of foam behind the trim will make a big difference. New gaskets? Leakage at the windows may be coming from failed or poor installation. That can be redone. Take a close look at one of the windows yourself or see if the local utility has a free energy audit service.

You probably know about Build-It-Solar, but anyway http://www.builditsolar.com/References/windowanalysisrs.htm

http://www.builditsolar.com/References/Half/HP118_pg48_Reysa.pdf


Do a life cycle cost analysis on any window you do purchase. Often the most expensive highest efficiency window is not the most cost effective. In other words, you may get 80% of the savings for 20% of the costs. Not always, but it is a possibility.

Sacramento looks like a really nice climate. Perhaps some exterior sun shading on windows would pay back quickly.

My exterior window/doors are 20 years old and so far are just fine. I have had a seal or two replaced, but no reason why these will not keep working well for many years.
 
This is way ball park but one of my windows was roughly 24 sq.ft. The price and hanging was 1100 and 200=1300/24=54.16 bux/sq.ft. Way rough idea!
 
These windows have a few little slots at the bottom of the frames, which are just holes to the outside, so it's not completely sealed. I guess they're there for some reason, condenstation (which I don't have), air pressure, or whatever reason I dunno??? I'm thinking of seal'n those with some clear silicon, I don't think it's much but I guess it might help. So, when I close the single cell shade (r-value = 0.01) and zap it with IR gun, it's about 5 degrees warmer then say naked window, not sure if this is a fair test though. It just seems like shutters (r-value = 6) would help create an air barrier too and better overall comfort.
 
FPX Dude said:
These windows have a few little slots at the bottom of the frames, which are just holes to the outside, so it's not completely sealed. I guess they're there for some reason, condenstation (which I don't have), air pressure, or whatever reason I dunno??? I'm thinking of seal'n those with some clear silicon, I don't think it's much but I guess it might help. So, when I close the single cell shade (r-value = 0.01) and zap it with IR gun, it's about 5 degrees warmer then say naked window, not sure if this is a fair test though. It just seems like shutters (r-value = 6) would help create an air barrier too and better overall comfort.
Click to expand...

I would think they would be seep holes. If they are and you seal them, you will then have moisture problems. I am not a window guy but.... that would be my guess.

Shawn
 
If you can feel the wind blow through your windows, then make it so you can't. Infiltration makes more much more difference than insulation.

About 8 years ago I put some plastic film on my west facing windows. It's a low-e coating. Made a huge difference, and really inexpensive. Tinting film -- the kind that adheres to the glass.

Generic double pane windows are usually about R-2. Good triple pane windows are usually R-3 or R4. 3 is better than 2, but it's not a huge difference in the big picture. If they're non-opening windows you can get interior storm windows for pretty cheap that will add a lot more insulation value.

At work, my office is more comfortable than everyone else's. the 1930's single pane windows are fairly tight, as far as things go, but they're big, and so they're a huge heat sink in the winter. I just put up some thin fabric curtains on regular rods. Stops a lot of the convection draft. The material was probably $.50 a yard on sale. Call it $4 for two really big windows.
 
If you can swing it, switch to casement windows. They seal much tighter than the double or single hung type. They are also more burglar resistant.

If you are getting baked out by the summer sun, look into some sort of shading option. A pergola might work for you, depending on your house and property layout and the resulting sun angles.
 
I'd also suggest some sort of shade for the south facing windows to block the summer sun. It's high in the sky so it shouldn't take much to shade them. There are some nifty calculators/programs online that will give you a rough idea of how deep and how high above the windows a shade needs to be to block summer sun but allow in winter sun based on your latitude and longitude.

Alan
 
If you lived in the northeast like me, I'd tell you to look into installing interior storms made of acrylic. This would give you most of the benefit that replacing your windows does at a fraction of the cost. In your area, you probably have cooling costs in the summer too (we really don't) so new windows might be the way to go. The link below will point you to a program from Berkeley that can help you get at what the benefit would be from window replacement and which glazing might be best in your area:

http://windows.lbl.gov/software/resfen/resfen.html
 
I would set up the house so it takes full advantage of the winter solar gains when the sun's angle is lower. For the summer sun, the angle is more overhead. This can be shaded with arbors that grow grapes, or other vines in the summer.
 
With Sacramento average low temp of 38F and average high temp of 92F, seems like it would take a very long time to get payback on new windows, but added comfort might tip the scales towards new windows. Area average highs and lows were I live are -7F to 81F. New windows in our house made a very big difference in elimination of drafts and improved comfort with our long, cold winters with strong NW winds. But even so, not sure the payback will be there. I rate comfort over payback.
 
First off I don't get how you get direct south sun in the summer through vertical windows, as the sun is high overhead in summer even well north of you. It's the east & west sun that should be more of a problem in the summer. If you need some shade to the south for fall & early spring I'd suggest some type of small awning, nothing too deep or it'll rob you of winter solar gain. I also don't see how plantation shutters would add R-6. It would take an inch thick panel of solid foam to get that. A more realistic value would be R-1 for the dead air layer created and about R-1 per inch of wood thickness, so maybe R-1.25 total. Interior shutters are also less effective for shading as part of the light that hits them is absorbed as heat & not reflected back out the window,
I'd look at passive ways to shade to the east and west from the outside whether you replace the windows or not. Deciduous trees & arbors, awnings, louvered awnings, porch... all will take care of overheating from sun in summer.

I 2'nd the advice to find out whether your windows are leaking air or your just feeling radiant heat loss through them. If they are leaky and not easily fixed by all means replace with good new ones if you can afford to, and casements are most efficient.
The "They" who say it's common to loose 50% of your heat through the windows are the window manufacturers & retailers. Those numbers are based on assumptions like leaky single-pane windows, very tight house otherwise, thick wall & attic insulation, high %age of glassed area, no accounting for solar gain... It's more common for homes to loose a much lower %age of heat through the windows. Windows are generally not an area where you get good bang for the efficiency buck, but new ones are nice. If your seals are good (or can be fixed-up) you could also consider adding storms which will add about R-1 and let all the light through (much cheaper than replacement windows).
 
If you have double hung, you can get replacement sash kits at about 1/2 the cost of full windows and frames, in either double or triple pain. I did my place (16 windows) 2 years ago for 5k including install, although diy is simple, I just didn,t have the time. Over the past 3 years I have reduced the utility bill from over 500 a month to about 90 avg. I have 3 doors to do next but that is going to be pricey as they are custom sized. WE Energies is not my friend.
 
I did the sash kits as well & yep they were about 1/2 the cost. You also don't typically loose glass area like you do with replacements. Works as long as your frames are in good shape & not leaky.
 
hey google energy film for windows.. the have tinted or clear and have alot of good +'s
i have been looking into it for my home
 
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