Low-emittance – or Low-E – windows are an increasingly common way to control temperature within the building envelope. Traditionally, windows were accepted as being “energy losers” – they lacked the insulation found in the rest of the building frame, so they were prime locations for heat to escape in winter or for cool air to escape in summer (either being conducted through the glass or slipping through cracks in the window frame).

But in the last 20 years low-E window coating has changed that. The coating is a thin film that can be applied to a normal window – at first the result was a green- or blue-tinted window, but now low-e windows can look just like traditional ones. Originally the coating was applied to the interior side of windows in cold-climate homes, because its properties prevented the conduction of heat. At the time, the technology could not be put to use in warm climates, to keep heat on the outside of the window, because the coating would have blocked transmission not only of the sun’s thermal radiation but also of its light.

Modern low-E windows, however, can be used to save energy in all climates, because the coating can now distinguish between light rays and thermal rays, permitting the sunlight to enter the building envelope while bouncing the heat back. About half of all new homes are built with low-emittance windows. When you’re in the market for a new home, be sure to look for a house with low-E windows – whether you live in a cool or warm climate, they will reduce heat transfer and energy bills, making a traditional energy loser into an environmental triumph.

Check out this site for more information.

Along with weatherstripping, caulking is one of two essential techniques for sealing air leaks in your home. It is ideal for sealing gaps that don’t open and shut – for instance, where your fireplace or an air vent is built into the wall. It works best where cracks or gaps are less than ¼ inch wide. Caulking consists of applying a thick substance called caulk directly over gaps. The substance soon dries, forming an airtight barrier between the inside and outside. As an added bonus, caulking will also help prevent moisture from seeping into your home, which will help keep mold out, and it can be an effective barrier against insects.

Caulking should be done on both the interior and the exterior of your house.

On the exterior, the following locations should be caulked:

• In the joints between chimney and siding

Weatherstripping is an ideal solution to air leaks at the edges of windows and doors. Affixing a material to the space between door and window closures, or on their sides, can stop the leaks. There are many different types of weather-stripping materials; foam, felt, metal and vinyl are the common ones.

Foam is often the easiest choice because it often comes with an adhesive backing that makes it very easy to install. The strip of foam will compress when a door or window is shut on it, sealing air out. This type of weatherstripping will need to be replaced after 1 – 3 years.

For description of each, go here.

Installation

Weatherstripping is generally easy to install by yourself and can be done relatively quickly. Your materials will probably come in a kit with specific instructions, but to get an idea of the work involved in each type of weatherstripping, please visit the following websites:

Energy Efficiency and Renewable Energy’s Consumer Page: Weatherstripping

How Stuff Works: How to Install Weatherstripping

Lowe’s How-To Library: Weatherstripping Windows and Doors

Weatherization, Water & Energy Saving Products, Kits & Programs

When you conduct over 3000 Home Energy Audits per year you’re bound to run into some interesting opinions. Many people believe certain things about home energy consumption that are just not true. These “Energy Myths” have often been inherited from one generation to the next. “Grandma always said…” is the typical preface to many of these energy myths. But a whole lot has changed in the last 50-100 years that makes grandma’s recommendations obsolete. Sorry Grandma. So after hearing many different Energy Myths from many different energy customers, the staff of Conservation Consultants got together and compiled some of the most common ones into a list of… drum roll please…

Top 10 Home Energy Myths

10. Myth: Closing off vents will help save on your heating bill.

Closing off vents, or putting a piece of cardboard over a vent is not typically a good way to save energy. Modern forced air heating systems balance their pressure load throughout the house. If one vent gets turned off it effectively unbalances the system. If you have forced air heating/cooling, you have two types of vents in your home; return and supply. Return is where your HVAC system inhales and supply is where it exhales. Just blocking any old vent is bad practice first off because you definitely don’t want to block a return vent, your heat would not work. But you don’t want to block vents because puts the system out of balance. Pressure will build up in in the ductwork, causing excess leakage into the walls. And less air will circulate through the system. Less air through furnace means less warm air in house which means a colder house. This sort of defeats the purpose. For more information on why you shouldn’t close off vents, go here.

9. Myth: Fiberglass Insulation alone will stop cold air from coming into your home.

While insulating is important, the job is not done until a home has been air sealed. Air sealing is the process of stopping air leaks and drafts which often occur though cracks between drywall and baseboards, windows, doors and any holes in an exterior surface. Insulating is like putting on a warm winter sweater, while air sealing is like putting on a windbreaker so that air doesn’t blow right through the sweater. Lets say you’ve got a hole in your attic floor where you can feel cold or warm air coming through. Putting a piece of insulation in this hole accomplishes very little. Air passes through most types of insulation quite easily. What you need to do is block the hole off using drywall or fiberboard and then insulate it with fiberglass Batt or loose fill. Or better yet hit two birds with one stone by using insulating foam board with a foil back, it blocks air and resists temperature differences. These items can all be purchased at your local hardware store.

8. Myth: Microwaves use a lot of electricity.

The simple explanation to this energy myth is that in the past microwaves used a whole lot of electricity – when they were first produced as giant appliances that took up a whole kitchen counter. Today’s technology makes microwaves the most efficient way of heating food or beverages costing approximately $1.00 per month for every fifteen minutes of daily use.

7. Myth: A dripping faucet is no big deal

At a glance, a faucet that drips may not seem to be a big deal. But try putting a gallon jug underneath that drip and you’d be surprised how quickly it’ll fill up. I hope you’re sitting down because that little drip could use 300-4,600 gallons per month!!!! Now if you’re still sitting, you shouldn’t be, you should stand up and go fix that dripping faucet!

6. Myth: Compact Fluorescent light bulbs don’t turn on when you flip the switch, have poor light quality and make buzzing noises.

Energy efficient lighting, such as Compact Fluorescent (CFL) bulbs have really gotten a bad reputation from this pervasive energy myth when in fact they have nothing in common with the old-fashioned fluorescent bulbs of cubicle-jammed offices. Back in the 80s and 90s fluorescent lighting lights always took a second to warm up and turn on. But compact fluorescent light bulbs have come a long way technologically. Manufacturers have been able to make it so that they come on immediately, are brighter and don’t emit that annoying humming sound. And don’t forget how much they will save on your electric bill ($20-50 per bulb over its lifetime) and how long they last (10,000 hours or approx 7 years)

5. Myth: You can save water by putting a brick in your toilet tank.

This one we can directly attribute to Grandma. But while putting a brick in your toilet tank will displace some water, thereby saving the amount of water that goes down the drain, it will also erode. “Erode?” you say. Yes, bricks are made from soils all of which are susceptible to erosion. Once the erosion starts, the flushing water pulls off little abrasive pieces of brick which end up tearing holes in your toilets rubber seal. These holes then let water through in what is called a Silent leak, which can cost you lots of money in the long run. Sorry Grandma.But this whole displacing water thing is a good idea, just not with a brick. So what we recommend is either a water bottle filled with water with the cap on (and perhaps some rocks in the bottom of the bottle to weigh it down) or else a device known as a toilet tummy, which hangs off the inside wall of the tank and displaces over half a gallon of water per flush.

4. Myth: Your house will heat up faster if you set the heat up higher than you’d actually like it. aka “It’s cold in here, let me crank this thing up to 90.”

This one’s a bit of a no-brainer. Your house will heat up to around 70 just as quickly if you set it to 70 as it would if you set it to 90. Setting it to 90 will only waste energy when your furnace actually responds by heating it up to 90. Chances are you’ll forget to turn it back down. And I can guarantee that you will not feel comfortable at 90 degrees. So why not just set it to the temperature that you’d like it to be. Your thermostat doesn’t work like a gas peddle. It works more like… well… a thermostat.

3. Myth: Turning down your thermostat uses more energy because it has to work harder to make it cool/hot again once turn it back up.

This energy myth costs utility customers loads of money during the cold months. Turning your thermostat back (or purchasing a programmable thermostat that will do it for you) while you are away or asleep can only save you money, it will never cost you more. The explanation for this is a bit complicated, but the key points are that your home is much more resistant to heat loss than you may think, furniture and carpeting retain enough heat so that your furnace will not have to work that hard to raise back up to a comfortable temperature. The longer that the furnace is off, the more savings you will achieve because the energy used to reheat a space is always less than or equal to the amount of energy used to keep it at a consistent higher temperature.

2. Myth: “Flipping the light switch on and off makes your electricity bill high!”

This energy myth has induced many parents to yell at their children: “stop flicking that switch – your bringing up the light bill!” In fact, turning lights on and off does NOT use more electricity, so turn off the lights when you don’t need them and on when you do need them! If it’s on then it’s costing you money… if it’s off then it’s not.

1. Myth: “Energy efficiency is expensive… I can’t afford compact fluorescent light bulbs, blown-in insulation, energy star appliances and efficient HVAC systems.”

Although some energy efficiency “measures” (Energy star appliances, insulation, Compact Fluorescent light bubs, solar panels, Green materials etc) may be initially more expensive than their conventional counterparts, they all end up paying for themselves, some almost immediately. The “Payback period,” as it’s called, is the time that it takes for an energy efficiency measure to save enough energy (aka money) that it has paid for itself.

“What?!?! Saves money?” You may ask, “But it cost me money… how does it save money?” Well, to clarify, here is a general example. Lets say you are shopping for a new furnace in your home. The salesman shows you a few options. One, an 80% AFUE behemoth that costs somewhere around $800. And another, a 98% AFUE that costs a bit over $2000. You say, “Ohh boy I can get a new furnace for $800, I’ll Take it!” Then you go home, put in the new furnace , winter arrives and before you know it your monthly Gas bill is $350!!! If you’d have bought the more efficient one your Gas bills could be around $200 (Still higher than it could be, it wouldn’t hurt to insulate) But what this amounts to is a $150/month savings. That means it will only take 8 winter months to make up the cost difference and then a little over 5 months after that, it has paid for itself. While the less efficient furnace ends up costing you way way more than even $2000 in the long run. What you need to have an eye for is the long term cost of a measure rather than the price tag. The low price tag on a cheap furnace does not reflect the the high bills that you’ll be paying down the road. Though it should. The same can be said of any conservation measure. Light bulbs, insulation, solar panels, new windows. So, don’t think that you can’t afford to be energy efficient. Truthfully you can’t afford NOT to be energy efficient.

Weatherization, Water & Energy Saving Products, Kits & Programs

The following forms of insulation are less commonly used than fiberglass and cellulose, but this doesn’t mean they’re less desirable. Most offer unique advantages over more traditional insulation, although they may have higher initial costs or other drawbacks as well. We urge you to consider them and make the decision that works best for your home, your finances and your environmental commitment.

Structural Insulated Panels

SIPs are an insulation option for homes that have not yet been constructed. They are panels that are pre-built and designed to form the entire building envelope of your house. They are available as wall, ceiling, floor and attic panels, and your contractor can build the whole exterior of your house with them. Like foamed insulation, SIPS offer the advantage of sealing the building envelope completely and can have R-values of between 4 and 7. However, SIPs present fire safety concerns and, when they are made of foam, are potentially more attractive as dwellings for insects and rodents.

For more information on SIPs, please visit:

EERE Consumer’s Guide: Structural Insulated Panels

Toolbase Services: The Home Building Industry’s “Hybrid”

Mineral Wool Insulation

Mineral wool insulation comes in rock wool or slag wool varieties, and usually is found in its loose-fill form. Its application process is the same as that of wet-spray cellulose: the material is mixed with a small amount of water and sprayed into an open cavity. It is also available in batt form. Typical mineral wool insulation has an R-value of between 3.5 and 4.

For more information on mineral wool insulation, please visit:

EERE Consumer’s Guide: Mineral Wool Insulation Materials

A firsthand account of one user’s positive experience with mineral wool insulation

Even More Options

Beyond these insulation options, there are still further alternatives to traditional insulation. They include, but are not limited to, reflective insulation, vermiculite and perlite pellets and concrete block insulation. We invite you to do further research on your insulation options; the Department of Energy’s Energy Efficiency and Renewable Energy Consumer’s Guide provides an excellent resource:

Weatherization, Water & Energy Saving Products, Kits & Programs

Foamed insulation is a bit expensive initially, but lasts longer and insulates better than others. It is made of various materials in their liquid states, and can be sprayed, injected or poured into the building envelope. Because foamed insulation can be made of many different materials, its R-values vary widely, from around 3 to at least 8.

Its main advantage is that, after application, it expands throughout the building cavity to fill the entire space completely, then “cures” (partially solidifies) to its final state. This effectively seals the interior of the building, ensuring that the full R-value of the insulation is realized. This is something that cellulose and fiberglass cannot do. (Link to article on the difference between insulation and sealant.) Because it can be sprayed into existing wall cavities, foamed insulation is a good option for houses that are already fully constructed.

Special equipment and training are required for the installation of foamed insulation. Foam insulation is seen as more susceptible to insect and rodent burrowing. Some types of foamed insulation, including polyurethane and polyisocyanurate, often use chlorofluorocarbons or hydrochlorofluorocarbons to reduce heat conductivity. CFCs and HCFCs are known to deplete the ozone layer and to contribute to global warming. If you choose to use foamed insulation, please ask your contractor to avoid using a type that contains these gases.

For more information on foamed insulation, please visit:

EERE Consumer’s Guide: Sprayed-Foam and Foamed-In-Place Insulation

Weatherization, Water & Energy Saving Products, Kits & Programs

Cellulose loose-fill is best compared to fiberglass loose-fill because both offer the benefit of more effectively sealing the building envelope from heat transfer. Cellulose tends to offer a better R-value per inch (see chart below), and it is not a possible carcinogen. It also boasts some environmental credentials above those fiberglass can claim: it has a greater percentage of recycled content, its manufacture is about 8 times less energy-intensive and, when it is removed from a house frame, it can theoretically be composted. However, cellulose tends to be more expensive, and its installation can be more labor-intensive than that of fiberglass blankets. It’s especially important to ensure proper installation of sprayed-in cellulose because if it is left too wet, mold, mildew and even rot can form in the house frame.

An essential component of conserving energy is keeping conditioned air in your house and keeping unconditioned air out, meaning that in the winter hot air doesn’t escape and in the summer cool air doesn’t escape. Insulation plays a role in keeping your house warm too, but regular fiberglass insulation does not stop the flow of air. Typically insulation is effective at preventing heat transfer through materials (limiting your home’s ability to conduct heat), it cannot prevent air from actually sneaking in and out through holes and cracks. (The exception to this is sprayed-in Cellulose and some foam insulations that can both air seal and insulate)

The most significant air leakage occurs at cracks in drywall, most often at barriers between the conditioned area of the house and the attic, basement and crawlspace. Cracks along the sides of windows, doors and outside walls are also significant sources of leakage. Many steps toward sealing your home are best done during construction, but some improvements can be made to an existing home structure – and are relatively inexpensively. According to the EPA’s Energy Star Program, air leakage accounts for between 25 to 40 percent of heat loss, so air sealing can really pay off. A good first step toward air sealing is to perform a blower-door test to determine where your home’s leaks are.

When you are air sealing your home, keep in mind that all enclosed spaces also need ventilation. Circulation between stale air from the house, which contains carbon dioxide, household chemicals and other pollutants, and outside air is crucial. But installing a ventilation system is both more effective and more energy-efficient than allowing drafts to sweep through your home whenever it happens to be windy.

For more information, please visit:
A Fact Sheet from the Department of Energy’s Web Site for Energy Efficiency and Renewable Resources

The EPA’s Guide to Home Ventilation

Weatherization, Water & Energy Saving Products, Kits & Programs

One important alternative to fiberglass (link) insulation is cellulose. Cellulose is installed with machines that blow it into attics or spray it into wall cavities. Cellulose is made from shredded newspaper and is a good insulator because wood, from which the paper is derived, has a heat-resistant cellular structure. Typical R-values range from 3.5 to 3.7.Cellulose loose-fill offers the same benefits over fiberglass blankets as fiberglass loose-fill does: it is more effective at insulating an entire space because it can fill oddly shaped spaces and let less air through. In spaces like attics where the insulation rests on the floor, dry cellulose can be blown in, while in vertical spaces like wall cavities the shredded newspaper can be purchased that is dampened and sprayed into place to ensure even, effective application. This technique is used more often in new constructions.

For more information on cellulose loose-fill, please visit:

U-Mass Dept. of Natural Resources Conservation: A guide to cellulose with useful tips on installation

DIY Network: A brief guide to cellulose installation

Link to: Cellulose v. Fiberglass

Link to: Fiberglass

Link to: Insulation

R-value is a measure of a material’s thermal resistance – the degree to which a material allows or does not allow heat to be conducted through it. In our context it applies to the insulation used to keep houses warm in the winter and cool in the summer. It’s measured both by the thickness of a given insulation material and by the structure of that material, so 2 different types of insulation with the same thickness can have different R-values. Comparing the R-values of various types of insulation is one of the most important ways to determine what type of insulation to use, and how much.
If a home had no insulation at all, the thermal resistance would be measured by the amount of air within the wall cavity, the air would have an R-value of 1 per inch (extremely inefficient). Fiberglass, a common type of insulation, ranges from an R-value of 2 to 5 per inch, depending on the type. Although R-values are measured by thermal resistance per inch (like an R-value of 3 per inch), the reference to thickness is usually not used (so instead we just talk about an R-value of 3).
As we’ve said before R-values and insulation make up only one of the two parts of the “envelope.” The other equally important component of the envelope is Air Sealing.

Recommended R-values vary depending on where in your home the insulation is to be placed. To find a the correct R-value based on your home’s construction and location visit Department of Energy’s ZIP-Code Insulation Calculator

Unfortunately, most houses built today are constructed with 2×4 framing, and you can only fit so much insulation in that small of a space. 2X4 framing limits the potential R-value (for Fiberglass Batt) that can be fit into the wall R-13. If you are constructing your home or doing major remodeling, an excellent step would be to install 2×6 studs in your exterior walls. This will allow you to fit more insulation between the interior of your home and the cold or heat outside. Your home will feel more comfortable and you’ll save on energy bills. Check out the following chart, which lists some common types of insulation and their approximate R-values.

R-Value Table

       Material					R/Inch
       Fiberglass Batt				3.14
       Fiberglass Blown (attic)			2.20
       Fiberglass Blown (wall)			3.20
       Rock Wool Batt				3.14
       Rock Wool Blown (attic)			3.10
       Rock Wool Blown (wall)			3.03
       Cellulose Blown (attic)			3.13
       Cellulose Blown (wall)			3.70
       Vermiculite				2.13
       Autoclaved Aerated Concrete		3.90
       Urea Terpolymer Foam			4.48
       Rigid Fiberglass (> 4lb/ft3)		4.00
       Expanded Polystyrene (beadboard)		4.00
       Extruded Polystyrene			5.00
       Polyurethane (foamed-in-place)		6.25
       Polyisocyanurate (foil-faced)		7.20

Table Source: http://www.coloradoenergy.org/procorner/stuff/r-values.htm