Weatherization Weatherization refers to the process of making your home more energy-efficient through taking…
The video follows an energy rater as he physically locates typical air leakage points in a home using a blower door test.
More than half the homes in Alaska were built during the pipeline construction boom of the 1970s and 80s and are now 25‐45 years old. Many of these homes are energy inefficient and lack modern ventilation systems. This helps explain why the average annual energy cost for homes in Alaska is more than twice the national average, with some regions more than four times the national average.
With the high energy prices of today, many Alaskans are looking to make their homes more efficient. There are almost infinite possibilities. To make sure you get the best bang for your buck and don’t create any unforeseen problems, a little planning is in order.
The first and only place to start is with an energy rating. This means an energy rater, certified by the state, comes to your house and performs an analysis of your energy use. The rater will look at everything—doors and windows, walls, appliances—to assess how tight your house is, how efficient your systems are and where you’re losing heat.
The energy rating will show you the weak points of your house and provide a list of recommendations. (Depending on your income, you may qualify for a free energy retrofit through the weatherization program detailed here.)
Once you have the report in hand, it’s time to prioritize. Which changes will make the greatest difference, either by reaping the greatest energy savings or improving the comfort of your family? You probably want to start with simple upgrades, which can make a big difference at a low cost.
First, seal air leaks in the house. You’re paying a lot to heat the indoor air, so you want to keep it from rushing outside through doors, windows and cracks in the floor and ceiling. Air sealing includes caulking windows, weather stripping doors, and spray foaming around any penetrations in the building envelope – for example, where pipes and wires enter your house. You also want to patch holes in ducts through unheated spaces.
Keep in mind that tightening a house will most likely create higher moisture levels inside that have to be dealt with through ventilation. It’s key for tight homes to have balanced, whole-house ventilation to keep the air fresh and healthy.
Once you’ve sealed up the house, it’s time to think about insulation. This could range from adding extra insulation to the attic to wrapping the entire house in rigid foam board. It all depends on your existing energy performance and how much you stand to save (which is what the energy rating tells you!)
Two of the most common retrofits are to blow more insulation into the attic or add foam to the crawlspace walls, because they are relatively simple and reap a very fast return on investment. Adding exterior insulation to the entire house, on the other hand, is much more involved.
You have to rip the siding off the house, install the insulation and reattach the siding, which has significant labor and material costs. You also have to follow building science best practices to ensure you don’t create moisture problems in the building envelope. If you’re using a vapor-impermeable insulation such as EPS foam, you have to add enough foam to the outside of the house to keep the sheathing warm and dry (at least six inches for a 2-by-6 wall). Depending on the current price of foam and heating oil, this type of retrofit is not economical for most homeowners.
If you have an old boiler or furnace, it might make sense to replace it with a newer, more efficient model. (Word to the wise – make sure to complete other efficiency changes first so your appliance is properly sized for your house.)
If you have single- or double-pane windows, you could save energy by upgrading to triple-pane, but it could have a slower payback than other retrofit options. (Check out ways to improve your existing windows here.)
The best plan will vary for each house based on the age, condition and systems of the house, as well as your personal goals and budget.
Making Your Improvements
While each home is unique, there are certainly trends among regions, neighborhoods, and generations of housing. For homes sharing the same features, many of the recommended energy efficiency measures will also be similar. In Alaska, for example, most homes that participated in retrofit programs ended up insulating ceilings, walls, and under floors. Many also upgraded their heating systems and installed programmable thermostats. For more details, see the 2019 Home Energy Rebate Program Summary here.
A few common retrofit measures are listed here.
- Insulate the roof
- Insulated slab and foundation walls.
- Air seal around windows, doors, electrical outlets, etc.
- Super-insulate walls
- Replace doors and windows with energy-efficient models, and specify glazing based on the house’s exposure to the sun.
- Ensure adequate ventilation based on IRTC code.
- Make sure combustion appliances are vented properly.
- Add occupancy sensors to heating & ventilation equipment
- Specify high-efficiency mechanical equipment and heat pumps, where possible
- Reconfigure plumbing to distribute hot water efficiently.
- Insulate hot water pipes
- Install blanket on your water heat
- Choose a high-efficiency water heater
Lighting & Appliances
- Install energy efficient lighting when current bulbs expire
- Eliminate phantom electrical loads by installing power strips
- Replace old appliances with newer, efficient models
Don’t Forget to Ventilate!
When weatherizing or retrofitting, it’s critical to look at the home as a whole system. If you tighten up the envelope without providing adequate ventilation, for example, you create the risk of trapping too much humidity in the house or backdrafting dangerous gases through your combustion appliances. That’s why it’s important to start with an energy audit to understand the way your home handles air and moisture.