Will New Windows Greatly Reduce Your Energy Bills?

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FenEx
Posts: 553
Joined: Thu Oct 07, 2004 11:18 am
Location: Illinois

Will New Windows Greatly Reduce Your Energy Bills?

#1 Post by FenEx »

I imagine this is why most of you found this site in the first place. The correct answer is... they might. I'm sure this isn't the preferred response.

Your windows are only part of a very complex system... your home. Every home is different and every climate doesn't care... it just does what it does. The neighbor next to you in the same model home might change windows and save 50%... and you might do the exact same and save nothing. It might not make sense.. until you apply science.

Energy is heat and follows it's own laws. It's laws tell it to move to a lack thereof by any vehicle available. Air transfer is the easiest but many others are readily available in most homes. Conduction, convection and radiation are the primary taxicabs. If your neighbors home is properly insulated and airtight, the energy might have been primarily using the old windows as the vehicle to move in or out. If your home isn't, new windows will only tranfer the energy to the next cab... like your walls or roof.

Think (ATM) = money. Air, Temperature and Moisture always move in relation to each other. If you address one and not the others, they will bring it along for the ride anyways. A typical 2,500 square foot home has over a half mile of cracks and crevices in it's shell. Insulation defects DOMINATE the thermal performance of any assembly. If the insulation in that shell has even 5% of gaps or openings, it reduces the entire shell's insulating value by up to 70%!!! The effect is even worse with higher initial R-values. The air takes the energy for a free cab ride and steps on the gas. Heat does not rise, it moves equally in every direction. Only heated air rises when it is not driven in another direction by predominant pressure or airflow.

If your house is well insulated and very airtight, then your windows might be the primary source of heat loss/gain. Changing these windows with a well insulated and airsealed product might make a huge difference in your energy bills. This would be the hope of everyone going through this process but it may also have very serious side-effects. If your old windows were a considerable source of air-infiltration, the reduction of this airflow will induce a negative pressure inside the home and may cause your cumbustion appliances to backdraft Carbon monoxide (CO). I have personally tested and witnessed this occurance by simply turning on a clothes dryer or a few utility fans. That was all it took to change the airflow. I have recently shown this effect to a well respected member of this board in person. If a shortage is measured, the necessary amount of "fresh" replacement air can then be supplied by controlled mechanical ventilation.

When you change any part of a structure's thermal or pressure boundaries with windows, siding, roofing & venting, etc., you have changed the rules and allowances. It is for these reasons and many more that I strongly recommend having your house professionally tested before and after any shell remodeling. The analysis fees are usually deductable from the contract amount of the work performed. These testing procedures are supported and recommended by the EPA and the USDOE and information can be found through their sites.

The primary objective is to save energy and improve comfort and air quality in the home. This can be achieved in almost every home in America... if you, Test... Before you invest.

Fenex

windowrep
Posts: 181
Joined: Thu Dec 02, 2004 11:54 am
Location: ne ohio

#2 Post by windowrep »

does anyone know of a good reliable company that will come into my home and do this for me???? anyone ???? anyone???? anyone???

Mass. window guy
Posts: 53
Joined: Mon Dec 06, 2004 1:30 pm
Location: Massachusetts

#3 Post by Mass. window guy »

Fenex,

What is done on these tests?
We have worked with companies that used the blower door tests and infra-red testing. Are there better tests than these ( or should I say more thorough test)?
I would definitely be interested in offering these services to my customers.

FenEx
Posts: 553
Joined: Thu Oct 07, 2004 11:18 am
Location: Illinois

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#4 Post by FenEx »

Windowrep- Check out www.energystar.gov or www.natresnet.org. They have certified rater directories and have links to others.

Mass. window guy- If you are already working with a company that uses the blower door testing... you are on the right track already. The blower door test (for others reading) is used to depressurize the entire house so that pressure readings may be taken at numerous locations around the home to locate the sources of the air-infiltration. Addressing the air-infiltration through some low-cost measures while you are upgrading windows can greatly improve efficiency and comfort for your clients. These same measures also reduce many moisture problems as air is it's primary carrier as well.

It would be a great service to provide to your customers. There are many tests that can be performed from infrared imaging, CO spillage and analysis, duct leakage (using a ductblaster), mold and mildew, HVAC analysis, the list goes on and on. HERS raters work directly with the EPA and test new construction for the Energy Star Homes program. BOP raters (Builder Option Packages) work with home builders to increase the efficiency of their buildings. As you are a contractor, you may want to look into BPI as they work with improving existing homes. You or one of your employees would get certified as a building analyst and combine it with atleast one specialty certification (Shell, HVAC, etc.). You may then work to get your company accredited. This would allow you to offer state and federal assistance programs and incentives to your clients as well, that they couldn't get otherwise. Well worth looking into.

Fenex

Mass. window guy
Posts: 53
Joined: Mon Dec 06, 2004 1:30 pm
Location: Massachusetts

#5 Post by Mass. window guy »

thanks fenex

JScott
Posts: 508
Joined: Tue Jan 04, 2005 5:06 pm
Location: Kentucky

#6 Post by JScott »

Thanks for sharing your time and knowledge.

FenEx
Posts: 553
Joined: Thu Oct 07, 2004 11:18 am
Location: Illinois

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#7 Post by FenEx »

You are very welcome Gentlemen... I truly enjoy the reward of even making a small difference... that's why I do it. I thank you for the notes of appreciation.

Fenex

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