Insulation is the low hanging fruit of carbon reduction. What does that mean? It means that there are very few activities that are so easy to do *and* have such a large impact. Maybe more selfishly — insulation increases your comfort and saves you money! What’s not to love about it.
Even if you don’t care about reducing your CO2 emissions, the other benefits of better insulating your home outweigh the costs. There is the added comfort of reducing air leaks and smoothing out the thermal properties of your home. It can make your home quieter, and it saves you money. It can also increase your home value and may earn you a tax credit. So really it’s a no brainer.
About 90% of US homes are under insulated relative to modern construction practices and municipal building codes, and 20% of annual US carbon emissions are related to home energy use. And about half of home energy use for heating and cooling.
It stands to reason that better insulation will reduce home energy use, and less home energy used results in less carbon pollution, money saved and fewer health problems from power plant emissions. Now if there were only a way to determine the exact benefits…
Fortunately, this is not an unsolvable problem. There are many models used by the construction and other industries to estimate costs and savings of different insulation methods (see the list of online calculators below). You can take those estimates of energy savings and easily figure out carbon savings. There are also well developed models linking the effects of air pollution on health, so that part can be figured out too.
Not long ago some university researchers did just that, they linked these tools together to learn about the potential carbon reduction and positive health impacts from appropriately insulating homes in the US.
In their article titled, Carbon reductions and health co-benefits from US residential energy efficiency measures, they found that bringing all residential homes in the US up to code for insulation would…
- Keep 80 billion tons of CO2 from power plants out of the atmosphere every year (electricity)
- Keep 30 billion tons of CO2 from home heating out of the atmosphere (gas, propane and oil fired furnaces)
- Keep 320 persons per year from dying early due to the impacts of air pollution from power plants
What is not given in that study are the intangible but also important implications of this work. Greater comfort in your home and saving money on your energy bill. Also… insulating homes across America would be a major source of employment for tens of thousands of people, that could last over a decade at least. Insulation is truly the low hanging fruit of climate change mitigation and money savings!
From top left, going clockwise… I used a caulk gun to mount foam insulation squares, the caulk gun, simple tools to do this, just starting, and done! Got a little carried away with the spray foam around the door jamb. 🙂 It’s probably best to spray about half as much as you think it needs, because this stuff expands like crazy.
Temperature gun (affiliate link) readings from left to right… attic temp, uninsulated door temp, and the final door temp. A change of -4.1F, which helped cool my office a fair bit.
In writing this post I learned that rigid foam board may be worse with regards to CO2 emissions than using nothing at all because a potent green-house gas (GHG) is used to make the bubbles in the foam. Glad I only used it for this small project. Often whole houses are covered in this stuff. GHG use for this type of product should be replaced by a less harmful gas by 2021.
According to EPA estimates, by better insulating and taking other energy saving measures, the average US home can reduce its energy bill by about 5 to 20% per year, depending on what part of the county you live in. If you live in a cool northern climate you will save more by using your heat less, than in a hotter southern climate running AC.
However, now and in the future, cooling will make up a larger portion of people’s energy bills across all climates. Thus, better insulation might reduce savings in northern climates, and increase it in the south. Also, as AC is primarily run by electric power and heat is often run via gas or oil in many areas, overall carbon emission should be lower. although this might be offset by areas that never needed AC before, now needing it to survive the summer.
Be sure to check out this comprehensive online guide to tax rebates and incentives from the Fed, state and local governments and utilities. If you are planning anything from purchasing energy efficient appliances, to a whole house insulation refit, this site could save thousands of dollars.
I used to walk by my attic hatch and could smell the air from the attic spilling down due to the ¾ inch gap. So I recently installed an attic door cover (affiliate link). Took me about 30 minutes. I used caulking and a staple gun to make an air-tight seal. Funny thing, if you buy this in the winter it will cost 2 -3x more than summer. I was going to do this last winter and the tent cost ~$120, but checked this spring and the same tent was around $40. Hmmm.
Here’s the temperature gun (affiliate link) readings, from left to right: before, temp of the attic door cover (the attic is about 120F), and temp afterward. Interestingly, the after temp was higher, but there was NO draft whatsoever, so overall a win. 😉
If you want to estimate your cost saving by adding insulation and performing other measures, there are many great online calculators you can use. Here are a few of them, from simple to complex…
- Energy Savings Calculator – a dead simple calculator from USA Insulation. I have no idea who these people are, but their calculator is okay by me, and it is within range of the more fancy calculators below.
- Insulation Savings Calculator – from the Cellulose Insulation Manufacturers Association. This pretty simple calculator is only for estimating savings and CO2 reduction for heating.
- For some of the following calculators you will need to determine your “degree days” for heating and cooling. You can do that here. Be sure to select “Average” breakdown to get a yearly number to use in the calculators below.
- Insulation Investment Calculator – determines savings from insulation for both heating and cooling. From Chuck Wright Consulting (I have no idea who that is, but his calculator is nifty). Chuck says…. “Insulation resists the flow of heat. Knowing the R values before and after an insulation upgrade and the average temperature difference across the insulation, you can calculate the amount that the insulation upgrade reduces heat flow. Knowing the cost of energy and the cost of the insulation upgrade, you can calculate the rate of return on your investment in insulation.” He also has a bunch of other interesting calculators on his site.
- Home Energy Saver – a fairly comprehensive to complex calculator from a US DOE Lawrence Berkeley National Laboratory. They say… “The Home Energy Saverâ„¢ (HES) empowers homeowners and renters to save money, live better, and help the earth by reducing energy use in their homes. HES recommends energy-saving upgrades that are appropriate to the home and make sense for the home’s climate and local energy prices. The money invested in these upgrades commonly earns “interest” in the form of energy bill savings, at an annual rate of 20% or more. HES also estimates the home’s carbon footprint and shows how much it can be reduced.“
Left to right –> gas water heater, insulation blanket, blanket on heater, and pipe wrap. Blanket is cut short for gas water heaters so the air vents at the bottom are not blocked.
Another super easy insulation project involves a keen eye and a can of spray foam insulation (affiliate link). Usually there are gaps where utilities penetrate walls that can easily be sealed off with a little foam. If you do this, figure out where all the holes are that you want to plug. Most cans of this stuff can not be reused at a later time. Look under sinks, behind major appliances, etc.. You can also find gaps outside your house where water pipes or other utilities penetrate the wall. If you spray too much, just let it harden then trim off the excess. Also, be sure to wear gloves and eye protection when you use this stuff. It’s pretty noxious until it dries.
I found a very detailed PDF guide from the EPA about sealing air leaks and insulating your home in the course of writing this post. Seems like I have done many of the measures shown, but there are still many more to do.
The really big step is yet to come. The biggest insulation project involves the attic. This also has the biggest upfront cost, but also the biggest cost savings. There are many companies out there that do this, although any reasonably able do-it-yourselfer can do it on their own. For me, I’d rather pay a pro to crawl around in my attic getting all dirty. Also, they’d probably get it done in a day with a crew, whereas it’d take me a week at least doing it on my own or with an inexperienced helper or two.
When I finally get my attic done, that will definitely be another post! In the meantime, enjoy this YouTube video about this. I have no idea who this guy is but he sure made a great video! 🙂