Decreased Energy Savings?

[whaas]

Sorry for all the posts!

I've been considering window replacment of my 15 year Semco dobule hung wood windows. There is a storm window.

My gas and electric bill average $100 for the winter months in Milwaukee, WI. I think that is pretty darn good.

So as long as I have a correct installation of the Softlite Elements I should maintain the same energy bill, right?
I understand the U and SHGC factor will improveIs but is it possible I will lose energy efficency now that the storm window is gone and not as much sun is coming in during the winder months?

Assume all varibles remain constant, only change is the window.

[Windows on Washington]

Depends on several factors.

How much Southern exposure do you have. While unlikely, there is the potential for new replacement windows to cut down on the passive solar aspects of the home and in turn, raise your heating bills.

This is very unlikely, but just throwing it out there. Do the windows leak air, water, heat, etc?

[whaas]

My house is open to all exposures. I planted some trees on the south and southwest sides but they are pretty small yet.

On a sunny day the sun runs from the southeast corner (from the kitchen) to the southwest corner (the dining room). Of course its the warmest side of the house in winter and summer.

Some windows do leak some air. Its really tough to guage....usually I just run my hand all around the various seams and corners when its windy. A couple are pretty much air tight others definitly have air coming in...when the wind is blowing directly on the window.

My concern is that we use the heat pretty much from late October to late March....then only use the AC from June to August.

I think where your going is that while I may lose that heat via the rays I may regain with limited air leakage.

[shamu]

How many windows? Square footage of your home? 2 story or 1? Brick or siding? How well is your home insulated? Heat source? How efficient is your furnace? All things to consider. $100/month is pretty good (I wish mine were that low) and I would guess that replacing your windows may not bring that cost down much.

[whaas]

Not sure I understand all those other varibles. They all stay contant.

I'm trying to understand if its possible to see a decrease in energy savings if I switch out the windows that have a storm now.

Only variable changing are the windows.

In the end I think its impossible to know without knowing how much air leakage there currently is and how much will be eliminated by replacing the windows.

One thing I always wondered....if the windows feels cold, but they aren't letting any air in...does it actually feel colder...as if the windows are acting like a refrigderator?

[shamu]

Was not considering those as variables, just trying to get a better understanding of your situation and other areas where you could maybe spend money that would have more of an impact. Depending on the number of windows you have, that may or may not be where you should be looking to make a change.

[whaas]

Gotcha!

1.5 story built in 1995.
2,000 sq.ft
Aluminum siding
Forced air heat
Furance repalced in 2006
I don't know what the r-value is of the walls

[whaas]

I forgot to add...

There are 15 double hungs, mainly 58" tall x 40" wide.
2 pictures windows maybe 58" x 58"

[HomeSealed]

I guarantee that you will not experience an energy loss, you probably won't save a ton either, but you WILL NOT experience a loss. This isn't the arctic circle where you need a really high SHGC, we have our good share of warmer weather as well.

[Windows on Washington]

Milwaukee is a very heating degree dominated climate (roughly 15 to 1). If the air leakage with his older windows is not the problem and he has storm windows, it is very likely that if he selects the wrong replacement window for his application that he could negatively impact his energy consumption.

http://www.climate-zone.com/climate/uni ... milwaukee/

Look at his energy consumption. He runs the heat for 6 months and the AC for 3. While a replacement window will cut down on his radiant losses in the winter, if he selects a window with a low SHGC, I would venture a guess that his heating bills may go up.

The line for higher SHGC windows is not as far North as you think.

http://www.wbdg.org/resources/psheating.php

[HomeSealed]

I'm very familar with the weather in Milwaukee as I live here. There are two points that I would make: 1: 15 yr Semco's are horrible, with or without storms, 2:There really are no low shgc choices in this market. They all run in the range of .32 or better. I stand by my statement that the OP WILL NOT lose any energy-efficiency by replacing his windows unless he chooses utter garbage to put him or has them installed improperly... Would it be a sound investment?... That is another story as it is hard to improve much upon $100 per mo. heating bills.

[Windows on Washington]

Not trying to be argumentative with you here HomeSealed because I am sure you know this market.

I am trying to separate out facts from ideas to most appropriately answer the poster's questions.

Saying a window is horrible with or without storms is a broad statement. If the window, with the application of a storm window, is air tight, I will stand by the fact that the customer may negatively impact his energy consumption if he chooses a low range SHGC window.

There are quite a few windows out there that need heavy Low-e coatings to cut muster for Energy Star Tax credit muster. If he stuffs a window in his openings that has an SHGC of 0.25 or lower, he can kiss most of his passive solar benefits goodbye and potentially his modest heating bills.

http://escholarship.org/uc/item/5p95w76m

[HomeSealed]

I don't take it as argumentative, nothing wrong with a healthy debate. ... I am very familiar with the product that he has in his home, and I can say for certain that it was not a good product when new, and certainly no better after 15yrs. In fact, that is actually longer than the normal life expectancy of that window from what I've seen. Further, the OP did state that there are noticeable AI issues on multiple windows and that they are "very cold". I realize that you are commited to your position at this point, and I do understand the scientific basis behind your concern, however I am 100% certain that the superior sealing and thermal performance of a quality replacement will more than make up for the small loss solar benefit. I say this with confidence as on many occasions, I have replaced 10-15 yr old vinyl windows with clear IG that still sealed well, and seen homeowner reduce energy consumption substantially. The reason that low u-value, and mid to low shgc, are all that is offered around here is because it is what yields the best results. Believe it or not, Milwaukee has a VERY saturated and well informed window market. If higher shgc was the best way to go around here, it would be pounced on by every company trying to get an edge on the other guys.

[whaas]

Great discussion guys, thanks for taking the time.

I used the bill analyzer from WE Engergies and my average bill from 2/25/08 to 1/27/10 is $84.52 per month.
2000 sq. ft home, 1.5 story built in 95'.

I originally wanted to get windows for aesthtics and easy maintaining. I have 2 windows that I actually have to put up plastic...works wonders, but a PITA. Some storms are rotting with mold...north and east facing.

The SHGC does make me nervous...I was told my current windows (with the storm) are probably close to 0.43. It gets super hot in the summer but I just keep the cellular shades down during the day.

The sun floods a bay window in the kitchen, then a bay window in the dining room, then a large patio window in the living space.

I'm thinking about replacing the windows in the bedrooms (more problems) and keep the windows in the living space.

[HomeSealed]

I have to say that your energy bill is really amazing! I don't know that I've ever seen a 2000 sq ft home around here with an energy bill like that. That must be your gas bill only, correct? Not including electric?