One of the most common questions I get asked is, “What should I look for in replacement windows?”
My immediate answer is always,“Wait, why are you replacing your windows?”
Window manufacturers, retailers and builders have done a fantastic job of spreading the perception that the key to energy efficiency in the home is through the purchasing and installation of new windows, but I’m going to share some myths related to this industry that should help you become a more aware shopper and homeowner:
1. The Window Salesman Myth
When talking to any sales person trying to sell you windows, all the factual-sounding information they share is, unfortunately, based strictly on subjective data.
First, from a basic insulation value, a single pane window is about a R1.5-R2. As a comparison, a NEW high-end window replacement is around R3.5-R4. In relation to all other types of insulation materials that exist in your home, even the BEST windows you could buy would not come close to competing for significant energy savings. The good news is that in most homes, windows don’t make up a significant amount of the house anyway, so in truth, even if energy modeled windows had a R20 value, they wouldn’t make a significant difference on the heat/cooling load of the house.
2. The Low E Window Myth
Everyone wants Low E windows because they come with the perception of being more technologically efficient, but are they the state-of-the-art, top of the line windows that you must have? Simply put: ABSOLUTELY NOT! Low E windows only reduce the radiant load so they are highly beneficial in the cooling season but detrimental in the heating season. So, unless you are living in Hawaii, Florida or the Caribbean, Low E is not a smart choice (but, you’ll never hear that from the guy selling Anderson windows at Home Depot)
3. The Drafty Window Myth
The most common complaint I hear from clients is “my windows are drafty.” The truth is that in almost every instance, doing scientifically derived testing (a blower door, smoke test, thermal imaging, etc.), what they are feeling isn’t a draft, but rather basic science at work! Most of your drafts come from so many other places in your home, not the windows. When homeowners feel what they call a “cold draft” coming from their window, it is usually a cold convective loop caused by warm air from something like a supply grille or radiator. That air rises up, and then cools by the window’s cooler interior surface (remember R1-R4 at best). The cooler air then moves away from the window making a cold draft. This is not cold air coming in from the outside (but you won’t hear certain sales people say that).
At best, a window replacement job will yield maybe 5% on total energy savings for your home, with a payback of 30+ years. There are far more effective energy savings measures you make in your home at far less cost, and true experts in the energy auditing field can help establish those. This is easily shown through scientifically derived data from an Energy Star Audit. So, lets replace the myths behind energy efficient windows with solid, practical solutions that will help homeowners save more of their hard earned money.
See the original Blog Post at: http://holistichomeenergy.wordpress.com/
energyMusings is written by Sean Schmidt, President of Holistic Home Energy Services, an Energy Auditing & Home Performance Contractor in Maryland. In addition to being a certified Building Analyst and Envelope Specialist, Sean has been in the HVACR field for 20 years. He is currently the President of Heating & Air Conditioning Contractors of Maryland, sits on the Board of the Maryland Alliance for Fair Competition (MAFC) and is an active member of Efficiency First.