Every day you probably hear ads about how much you can save by making energy improvements to your home. Whether it’s a new air conditioning unit, double-pane low e windows, insulation, weatherization, radiant barrier, new LED or CFL light bulbs, the list goes on and on.
Yes, we all know that these improvements will save money, but are they a good investment? Here is a quick and easy way to figure out how much to invest in energy savings using the cost of money and return on investments.
Let’s say our home averages $200 per month in utility bills. Given an average home, it is pretty easy to drop a bill by 20% or $40 per month. This is pretty basic stuff like air sealing, switching to a programmable thermostat, installing a radiant barrier, better attic insulation, duct sealing, changing light bulbs and new air filters just to name a few projects.
So, if you could drop your bill by $40 per month it would put an extra $480 in your pocket over the course of a year. It’s not retirement money, but I’m sure you will find something to do with it. If you have a higher bill then the total will be even larger.
This is just like getting an extra $480 bonus at work, but it’s actually BETTER? Why? This is AFTER TAX MONEY. Which means if you were in the 20% tax bracket, you would have to EARN about $575 to end up with $480.
Now the REAL value is $575 per year. Ask yourself “How much would I be willing to invest to get a $575 bonus EVERY year”? Currently, in the investment world a 10% GUARANTEED RETURN is impossible. However, if you were to invest up to $5,750 in energy improvements and generate $575 in savings you would get a 10% return on your investment. In fact, on most homes you could probably get this much savings with less than $3000 worth of improvements which would result in over a 20% return on investment. During a tough economy, this is a SPECTACULAR RATE OF RETURN.
This is why so many people are spending (investing) the money to increase the energy efficiency in their homes.
Finally, all these numbers and assumptions are based on energy rates staying exactly the same. Over the long haul, do you REALLY think rates will stay the same? If rates go up then the payback and return on investment is even greater.
Is it worth it to invest in energy efficiency improvements? Unless you can guarantee at least a 10-20% return on your investments the answer is YES.
Tags: energy, energy efficiency, energy efficiency tax credit
There is some debate in the radiant barrier business whether to use a perforated or a solid radiant barrier product in an attic application.
In an attic application, you should ALWAYS use a perforated product. Period.
Perforated Radiant Barrier Foil
Why? Solid products like bubble foil insulation are called “Vapor Barriers”. A vapor barrier basically stops moisture from moving from point A to point B. Or, another way to view this is that a vapor barrier will “TRAP” moisture. I’m not going to get into the technical definition of what defines a vapor barrier (perm rating, etc), but here is an illustration of what IS and IS NOT a vapor barrier.
If you take a wet block of wood and put it inside a bag or an envelope made of perforated radiant barrier attic foil the wood block would eventually dry out. Therefore, perforated radiant barrier is NOT a vapor barrier. Moisture ALWAYS goes from wet to dry. If you did the same test with the wood block inside a plastic bag the wood would still be wet months from now. If moisture in its vapor form cannot pass through or object won’t “dry” then the product IS a vapor barrier.
Why is this important?
Virtually all (over 70%) of home issues are due to mold, mildew, rot, decay, etc. And moisture is the common theme here. DRY products don’t grow mold, rot or decay. The bottom line is that moisture in wall and ceiling assemblies is not a good thing. You want DRY walls and ceilings.
In cooler weather, the moisture INSIDE the home is greater than OUTSIDE. Think cold and dry. This is why our lips get chapped in the Winter and not in the Summer. Since moisture will naturally move from wet (inside) to dry (outside) it will pass through sheetrock, insulation and then into a typical attic. The LAST thing we want to do is TRAP moisture here. Moisture, attic insulation and wood do not go well together. A perforated radiant barrier will allow moisture to pass on through into the attic. We want our attics to be cool and DRY.
Using a perforated radiant barrier will not change the effectiveness of the reflectivity. Attic Foil has tiny pinholes about every ½ inch that allow for water in its vapor form to pass through (see picture). These holes make up a TINY percentage of the surface area and will not change the effectiveness of the radiant barrier.
Solid products like bubble foil insulation are usually not perforated and are a recipe for disaster when installed inside an attic. Solid (non-perforated) bubble foil is a great product when used correctly in applications like metal buildings. The problem is that solid bubble foil products are often MISUSED in residential attics. This is especially true if the bubble type reflective foil products are laid directly over the attic insulation. Moisture will pass through the sheetrock and will get trapped in the insulation below the bubble foil insulation. This moisture will accumulate until it either condensates (turns to water) or freezes (turns to ice).
This is why it is critical to use a perforated tarp-like radiant barrier product. It will give you all the benefits of reflective insulation without the potential for moisture to get trapped.
I've written several other posts on this that you might be interested in. Check these posts below:
Tags: Attic Insulation, foil installation, perforated radiant barrier, r-value, radiant barrier foil, radiant heat
I still get this question all the time. “Can you explain why an air space is needed for a radiant barrier to work?” Watch this video for a complete explanation.
Basically it works this way. Radiant heat is heat that is transferred across either an air space or a vacuum. This is how the heat from the sun reaches the earth. Radiant heat acts similar to a sound wave. By definition, you MUST have either an air space or a void for radiant heat to even exist.
If you don’t have an air space then you basically have a solid. Heat can essentially only move through a solid by conduction. This is by direct contact. This is how an egg cooks on a hot skillet.
So, without an air space, you cannot have radiant heat. Without radiant heat there is no way to have a “Radiant Barrier”. In fact, because of the conductive nature of pure aluminum, if you install radiant barrier foil WITHOUT the required air space it will actually work AGAINST you and INCREASE Heat flow.
The bottom line is you MUST have an air space on one side of a radiant barrier for it to work.
Looking for more videos on this topic? Check out my posts below.
Tags: conductive heat, radiant barrier, radiant barrier foil, radiant heat, radiant heat energy
WOW, it’s been cold lately. Not surprisingly, I’ve received a bunch of calls and emails from people wanting more information on how installing a radiant barrier can help them in cold weather.
I put together a video to help illustrate how traditional attic insulation and radiant barrier WORK TOGETHER to make a home more comfortable and energy efficient.
Remember, traditional attic insulation – fiberglass or cellulose help to reduce Conductive Heat Loss. A radiant barrier will help to reduce Radiant Heat Loss. In cold weather, heat is lost in BOTH ways.
Combining good attic insulation and radiant barrier will give your home the best defense to stay warm in the Winter and cool in the Summer.
I've written several other posts on this that you might be interested in. Check these posts below:
Tags: Attic Insulation, cold climates, foil installation, radiant barrier, radiant heat energy
Paint applied as a Radiant Barrier
You may have recently heard some Radio/TV ads talking about an “Amazing Radiant Barrier Paint that is applied to the underside of your roof”. And how it “reflects” over 75% of the heat to keep your attic cooler and save you money on your utility bills.
Let’s get some facts straight. There is NO such thing as RADIANT BARRIER PAINT.
The term “Radiant Barrier” is supposed to describe products that “Reflect” over 90% of radiant energy (think light colored and/or shiny surfaces like aluminum, silver and gold) or have an emissivity of less than .10. This means they can only “Release” less than 10% of energy as radiant heat (think a potato wrapped with foil to keep heat from being released).
The term “Radiant Barrier” has been hijacked by the paint installers to try to confuse consumers into thinking they are the same. This is like hamburger calling itself a prime steak.
Paints like Sherwin Williams E-Barrier, STS Coatings HeatBloc or Solec LO/MIT are NOT the same as radiant barrier foil. I’m surprised the FTC has not stopped this fraudulent advertising or a lawyer has not created a class-action suit on the behalf of customers who thought they were being sold a “radiant barrier” by installers.
Paint products technically have their own name. They are called Interior Radiation Control Coatings or IRCC’s for short. This is not as cool as being called a “Radiant Barrier”. Ironically, most paints don’t even qualify to be an IRCC since the definition of an IRCC is a product that reflects at least 75% or emits less than 25% of radiant heat. Here are some test results of radiant barrier paints.
Paints will NEVER perform as well as foil radiant barrier products. Foil always reflects 97% of radiant heat energy. This is an indisputable fact. Radiant Barrier Foil is always superior to IRCC’s. Paints run into other challenges. Because radiant barrier paints are “applied” rather than “installed” you get inherent variables in the application process.
First, how can you tell without testing if the product was put on too thick or too thin? What about painting unprimed wood with paint? Common sense says it will be absorbed by the wood and reduce the “smoothness” required for a good low emissivity surface. You will also need to paint the deck AND the rafters to get the maximum benefit.
Finally, what about cheating? These radiant barrier paints are really EXPENSIVE, like $50 per gallon. I’ve seen guys use cheap silver paint, or mix water with the good paint to extend coverage and reduce costs, which will also reduce the effectiveness of radiant barrier paints. I’m sure there are many honest installers, but watch out for the bad apples.
The reality is that most radiant barrier paint products end up reducing radiant heat into the attic by about 20-40%. This is far below the claimed rates of 75%.
There are claims that foil is not effective unless you get the whole roof. This is NOT true. Any product, whether it be foil or paint has a cumulative effect, the more coverage the better. A tree over part of your home still helps, right?
If you compare the math, you could actually put foil (reflecting 97%) over half the home and get more heat reduction than applying paint (reflects 20%-40% in real installations) over the whole home.
Don’t believe anyone that says that radiant barrier paint is as good or as effective as radiant barrier foil. And remember, there is technically NO such thing as radiant barrier paint.
Tags: ircc, radiant barrier, radiant barrier foil, radiant barrier paint, radiant heat energy
The weather outside may be frightful, but in your attic it’s quite delightful. Well, it is compared to being in your attic in July. NOW is the time to think ahead and work on a few simple projects that can have a HUGE difference before you get your summer electric bills.
I’m about to reveal the FOUR SILVER BULLETS for making your home more energy efficient in HOT CLIMATES. I’m especially talking about your typical one-story, ranch style home in the South.
Picture yourself sitting in your living room on hot August afternoon. The sun is beating down and it’s about 95º outside. What’s between you and the bazillion degree sun?
Four layers: 1) Roof 2) Attic 3) Leaking Ductwork in the Attic 4) Insulation
If you fix each “layer” between you and the heat from the sun, your home WILL BE MORE EFFICIENT AND COMFORTABLE EVERY TIME!!! Guaranteed. It is not complicated; just follow the recipe for success.
Radiant Barrier Installation
Layer #1 – Roof
Problem: It gets to be about 150º or more and basically acts like a big sponge to absorb heat. This heat is then radiated to the next layer.
Silver Bullet #1 = Radiant Barrier
Installing a radiant barrier is the next best thing to a giant tree instantly landing over your home. Your roof will still absorb the heat, but now rather than that heat being transferred to the home, it will be reflected AWAY.
Layer #2 – Attic
Blocked soffit vent blocks attic ventilation
Problem: Because most attics don’t have enough (or proper) ventilation, the AIR inside the attic basically gets “Clogged” like a drain in a bathtub. The air has nowhere to go and it just heats up and “fills up” the attic. Hot air in the attic will heat up the insulation AND heat up your ductwork that is supposed to have nice cold air running through it.
Silver Bullet #2 = Attic Ventilation
Attic ventilation is real simple. All you need is holes in the top and holes in the bottom. The more holes, the more outside (relatively cool) air moves through the attic and the cooler the attic air. The lowest the air inside the attic can go is near ambient (outside) temperature. The overlooked key to fixing attic ventilation is usually more soffit vents.
Leaking ducts in the attic
Layer #3 – Leaking Ductwork In The Attic
Problem: Putting Ductwork in the attic is about a dumb as making ice cream in the oven. Since you can’t move the ductwork, at least keep it from leaking. Most homes have duct leakage ranging from 15-50%. Older homes and homes with old metal ductwork usually have the highest leakage. What this means is that probably 25% or more of the cold air you are buying is being blown into the attic OR Hot dirty attic air is being SUCKED into your home if the leaks are on the return side of the AC system.
Silver Bullet #3 = Seal Ducts In Attic
If 30% of your water from your sprinkler were spraying into the street, you would fix it today. Why not do the same for your ductwork? Have your ductwork sealed or replaced. A tight duct system will save energy and increase comfort. Plus, indoor air quality will improve by reducing humidity and dust from being pulled into the home.
Attic Insulation being blown in
Layer #4 – Attic Insulation
Problem: Most homes do not have enough attic insulation to create a good thermal barrier between either the heat in the summer and the cold in the winter.
Silver Bullet #4 = Attic Insulation
Increase your attic insulation to the recommend level for your area. Check the DOE (Department Of Energy) for recommendations.
There you go. Four silver bullets for fixing your summer electric bill. Your attic is waiting.
I've written several other posts on this that you might be interested in. Check these posts below:
Tags: Attic Insulation, Attic Ventilation, foil installation, radiant barrier, radiant barrier foil
Check out Chris Edwards at www.GreenLows.com installing Radiant Barrier Foil from Attic Foil. This video really shows how uncomplicated installing radiant barrier can be. As I mention in the video, the key is NOT to over-think the installation process.
In this video he demonstrates the Open-Ridge Method of installing radiant barrier. This is an excellent method for warmer climates and especially for homes that have ductwork in the attic.
Think of radiant barrier as shade and you are trying to protect your insulation (and the ductwork) from absorbing radiant heat coming off the roof and getting warmer. Simply staple up the radiant barrier and leave an air path for attic ventilation to do its thing.
Attic Ventilation is simple: Create a path for air to come in the bottom of the attic and out the top off the attic. If you install the foil in a way that does not BLOCK this path, you have it correctly installed.
Installing radiant barrier is a great Bang-For-The-Buck DIY project. Now is the best time to install radiant barrier while the attic is nice and cool. You will really appreciate it when the scorching heat comes back next Summer.
Looking for more videos on this topic? Check out my posts below.
Tags: Attic Ventilation, foil installation, insulation, radiant barrier, radiant barrier foil, radiant heat
