If you're looking to improve your home's performance, a great first place to start is with the insulation. Most homes, especially older ones, are seriously short on insulation. In this hot season, why bleed your air conditioning dollars out of the house?
First, R-Value. Insulation's effectiveness is rated in R-Values. "R" stands for "resistance" - resistance to heatflow, or cool airflow as the seasons change. You can look at it as the measure of heat gain in the summer and heat loss in the winter. The higher the R-Value, the greater the insulating power and the greater your potential energy savings.
Each region within the country has recommended R-Values for specific insulation installations. Insulation with different R-Values may be added together for a higher total value. Refer to this Energy Star guideline for the R-Value you need for your home.
Insulation typically is made of fiberglass matting called "batts". It can come as either "Faced" with a vapor-retardent paper called "kraft", or as "unfaced" which is just the fiberglass material. Also, you can buy it as a roll or in precut sections of 8 foot, which accomodates a typical wall height.
A common way to increase the homes insulative power is to install new fiberglass in the attic. Always use "unfaced" insulation and be sure to roll it to cover the most area. Don't cover ventilation points or light fixtures, which require air around them to function correctly. A typical bag will cover about 100 square feet, so premeasure your attic and buy as many rolls as you need.
There are other, new materials to use as insulation - one great idea can be found here at Stephanie Edwards's blog out of Texas. There are new, recycled materials coming out which I would recommend investigating if you have the ability and time to do so.
Re-insulating your home may be the most cost-effective way to begin "greening" your house and saving money in the process! If you are interested in more information about insulation read this Department of Energy guide, or do some online research into alternative materials such as cellulose. In this hot season, every bit of effort will yield a gain for you and your family, and to our national dependence on foreign energy. Go for it!
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For Lancaster PA homes for sale click here. Jeff Geoghan is a top real estate expert in Lancaster County, PA, and an involved community member. Jeff's work has been featured in the Lancaster Newspapers, WGAL Channel 8, PA Business Journal and Wall Street Journal. Jeff's blog on Lancaster County and its homes is nationally-featured. Contact Jeff for more help with your Lancaster PA Real Estate needs.
Hi HERS Rater, Could we talk you into joining AR so that we could get some information on Energy Ratings?
Sorry Jeff, hope you don't mind me hopping in here. I am trying to find a good, experienced Rater in my area.
Jeff- Good post. I really like the spray soy insulation the best. And am interested in the cotton insulation made from old blue jeans. See some of the links below of some different types of insulations I have used.
http://www.bondedlogic.com/ultratouch.htm
http://www.icynene.com/
http://www.soyoyl.com/home/home.asp
http://www.prosealinsulation.com/
Okay boys and girls, it's time for a little Insulation 101!
I've been an insulation auditor for 15 years working with contractors that wanted to be certified installers. As a field auditor I've seen it all, the good, bad and indifferent. The industry's dirty little secret is that 70% of all insulation jobs are under insulated. The cheating by the insulation industry is rampant. The FTC has issued special rules and fines (up to $10,000 per incident) for general contractors not meeting the contract requirements.
There are three reason why insulation is shorted. Operator error caused by a lack of training or equipment failures, mislabeled packaging my manufacturing and fraud (selling low bid and shorting the material to make up for it. Loose fill insulation, like fiberglass, can be fluffed up like whipping cream, giving the illlusion of adequate R-value (based on depth). But insulation depth is only an indicator of R-value if the density is adequate.
Increasing your insulation from R-13 to R-19 may not improve the thermal performance of your home. Heat moves three ways:
Radiation is heat movement through space. The sun heats the earth by radiation. Houses can be impacted by radiated heat that enters through window assemblies or through the roof.
Conduction is heat movement through a solid object. Heat transfers one adjacent molecule at a time.
Convection is heat movement through a liquid. Air is a liquid. Forced air HVAC systems transmit heat convectively as do convective ovens. Most of our heat loss in our buildings is convective in nature.
Fiberglass blanket is not effective at stopping air movement so it is not effective at stopping heat loss. Even when installed in a wall cavity fiberglass insulation is by-passed by convective air movement in the cavity through convective loops. Convective loops form when the air inside a wall cavity begins to move because it is cooled (and drops) along the outside wall and rises (as it is warmed along the inside wall. The warm air will rise until it get to the top and cools again as it hits the top of the outside wall, and drops. Pretty soon the cold air is pulled right through the insulation, in effect by-passing it.
When selecting insulation it is best to pay attention to density. Generally the denser the insulation material the more effective the insulation. Each insulation in the list below will out perform the insulation above it:
I prefer open-cell to closed-cell because hard foams can separate from the wood framing if the framing moves at all (wind loads, snow loads, humidity changes, etc.) Most insulation materials have an R-value of about 1 per inch. Would you rather have 1-inch of fiberglass (your furnace filter) or 1-inch of Styrofoam protecting you from the cold?
Since most of the heat loss in a building is convective through the ceiling you should consider installing a material that can seal the attic against air movement. If you can't afford open-cell foam you should consider air sealing the attic before installing cellulose. Fiberglass should not be used in an attic with high temperature differences between indoors and outdoors.
In no case should you upgrade your thermal envelop without investing in an energy audit by a qualified energy auditor. You can locate a rater in your location by going to www.natresnet.org. Experienced raters can inspect your house to determine what system(s) in the house are wasting energy. Chances are that you will not be able to address all the problems but can cherry pick recommendations based on investment and benefit. I recently removed R-60 cellulose insulation from my attic and replaced it with R-24, soy-based, spray-foam. I reduced energy usage by 50%. The cost, $4300 was recovered in 3 years.
In 20 years I've never found an economic reason to replace the windows. The typical payback on replacement windows is over 60-years. There may be plenty of good reasons to replace windows but energy saving is not one of them.