[I forgot to post this article from our October newsletter to this blog. Better late than never! -Fred]
Weatherization has gotten swept up into the maelstrom of partisan politics. A recent article in Newsweek magazine called the federal weatherization program "Obama's Big Green Mess" and prompted comedians like Jon Stewart to ridicule the effort as "Weather Blunderground." Earlier this year the Maine legislature ordered a probe into how a federal weatherization grant was spent (the probe discovered no malfeasance).
Whether you agree with the criticism of how $5 billion in federal money has been invested, at least the press is paying attention to the issue of how we're weatherizing our homes. As Oscar Wilde said, "The only thing worse than being talked about is not being talked about."
So let's talk about weatherization. In this month's tip I want to share some ideas about how we should go about weatherizing our homes, and what needs to happen once everyone is living in a weatherized home.
- Weatherizing our homes and buildings is a great idea (especially in Maine) because it saves money, conserves resources, and protects public health, if done right. The wasted money and horror stories reported by the media are due to poor training and incompetent workers.
- The first step is to examine your structure. It would be a good idea for a competent weatherization technician to conduct a simple walk-through inspection of every home every year to check for obvious moisture, ventilation, and heating equipment problems. Carbon monoxide from malfunctioning oil and gas burning appliances can kill you whether or not your home is weatherized.
- Before embarking on a major renovation, a competent professional should conduct a thorough energy audit, including a blower-door test and an infra-red scan. This examination will reveal how air and energy flow through the building. Work should be performed according to the recommendations in the audit. Once work has been completed, an energy auditor should check the quality of the work done. No weatherization job is complete without a check out audit.
- Weatherized buildings stay comfortably cool in the summer and warm in the winter by controlling the flow of air and energy. It is essential to prevent unwanted moisture from entering the building, to vent the moisture that is introduced into the building (such as in the kitchen and bathrooms), and to eliminate or vent sources of indoor air pollution. Before you start sealing up cracks and adding insulation, make sure you understand how moisture and air enter and leave your structure.
- Once you have an energy audit in hand, you can do a lot of the work yourself. If you want to develop your skills before trying your hand at caulking or installing insulation, contact your local community college. Many now offer weatherization training that you can complete in just a few days or evenings.
- At a minimum, your weatherization goal should be to ensure that your home can survive an extended loss of power during winter without the risk of frozen pipes or property damage. Once your home has been properly weatherized, you should be able to turn down (or even shut off) your heating system and go on vacation for a week in February without worrying about frozen pipes.
- If you own an older home, you'll likely discover that you must compromise energy performance in order to retain your existing structure. For example, there is only so much room in existing walls or ceiling to add insulation. In this case, it's even more important to have a complete energy audit so you can make an informed decision whether to attempt a weatherization project or build a new structure.
- Improving the physical structure of your home is just one step in bringing your energy efficiency up to a sustainable level. The next step is getting control over how much, how long and how intensely you heat and cool.
- Along with weatherizing our homes, each of us should create heating and cooling zones inside them. Think about how you use your living space, and make a long-term plan for your heating and cooling needs. Are you wasting money to heat rooms you rarely use? Do you like to keep different rooms different temperatures at different times of the day? Even if you currently have an inflexible central heating system without any zones, it's still worthwhile to develop a zone plan for the day when you upgrade your heating system. The better you can identify the areas you need to heat or cool, the more efficient you can be with your energy.
- Once you have your zones, controlling them is the next step. With a manual thermostat, you can turn down the heat when you don't need it, then turn it back up when you do. If you find yourself forgetting to do this (or you just like gadgets), you can invest in a programmable thermostat to do it for you. A new company has even announced a "smart thermostat" that learns how you use your home and doesn't have to be programmed. Check out the Nest Learning Thermostat.
- So you've done everything you can to improve your energy efficiency for heating and cooling your home. What next? Now you are in good shape to go to a sustainable energy source.
- The easiest sustainable energy system for most homeowners is one that converts the sunlight hitting your roof into electricity. In particular, the most trouble-free, long-lasting configuration is a photovoltaic solar array that is connected to the grid. This mean that panels are installed on your roof, an inverter is installed in your home, and when the sun shines, if you start generating more electricity than you can use, the extra goes onto the grid for your neighbors to use. Except for the fact that your electric bill goes way down, you'd never know you were using solar electricity. All of your existing appliances (including space heaters) work just fine with solar electricity, and unlike an "off-grid" solar system, you don't need any batteries to store the electricity your solar panels are generating. They just cleanly and quietly create power for the electricity grid, with you being first in line to use it. Best of all, in Maine, you can "net meter" all the electricity you send to the grid, which means if you send a kilowatt hour to the grid when it's sunny, you get to use a kilowatt hour of grid power when it's not. At the end of the year, you net what you sent and what you took, and pay the difference. Since you'll be producing most of your electricity in the summer, but need it in the winter, "net metering" is a great feature of solar electricity that makes the finances work out in your favor.
- If you decide to install a solar electric system, take a careful look at how you are heating your home. If you have really done a good job weatherizing, you may discover that electric space heating is a viable option. If electric heat isn't a complete solution, it may still be appropriate as part of a zoning plan for rooms that are seldom used or that need an additional heating source (such as rooms on the north side of your house). When planning the size of a solar electric array, be sure to include a scenario in which some or all of your water heating and space heating needs are met by your solar electricity, just to compare how much you'd pay for clean energy you generate yourself versus other forms of energy.
- Although electric space heaters are just about 100% efficient (i.e., they convert all of the electrical energy they consume into useful heat, unlike combustion heaters which always waste some fuel without converting it to useful heat and must vent hot combustion gases as outdoor air pollution), you can do even better. Heat pumps move heat from one place to another; each unit of electricity used to pump this heat can deliver more than one unit of heat. In other words, instead of sending your electricity into a resistor inside a space heater, you can send that electricity to a pump to move heat around. The typical way to move heat around is to put a fluid in a tube, depressurize it in an area where you want to absorb heat, then circulate and pressurize it where you want to release heat. A ground-source heat pump, or geothermal system, takes heat from the ground and moves it into your home. An air source heat pump takes heat from outdoor air and brings it inside (just like a freezer in reverse -- your freezer takes energy out of the cold air inside it and moves that heat into your kitchen). Although heat pumps are more complicated and expensive than electric space heaters, you may discover that your heating load is high enough that the extra expense is worth it.
- What else can we do with the solar energy being freely delivered to every address in the country? A second way to harness your share is a solar hot water collector. These systems are almost as easy as a solar electric system. Solar collectors outside get hot in the sun. A liquid (usually anti-freeze) is pumped in a loop to bring that heat inside, where it warms a hot water tank. The hot water can then be used for domestic purposes (sinks, showers, washing machines, etc.) as well as space heating. A big advantage of solar hot water collectors is that they are between three and four times more efficient than solar PV panels at capturing the energy in sunlight. A big disadvantage is that it is hard to share that energy with your neighbors. Also, there is no net metering program for hot water: use it or lose it. Unfortunately, you get the most hot water during the summer, and no one has figured out a clever way to "bank it" for use in the winter when you really need it.
- Even though solar hot water systems don't have the flexibility and net metering that is possible with solar electricity, many people are using them to heat their homes. It just takes a lot more planning and work to make use of solar hot water as an energy source compared to solar electricity. You should start with a comprehensive energy audit including time-of-day energy use calculations to get the most return on investment.
- A third way to harness solar energy for space heating is a solar space heater. Like a solar hot water heater, this is an efficient way to collect solar energy. But unlike a solar hot water collector, a solar space heater uses air (a simple fan) to move the heat from the collector to inside. As with solar hot water systems, extra heat from solar space heaters can't be shared with neighbors or net metered. Nonetheless, solar space heaters work just fine in Maine's climate and per unit of energy are the most afforable way to collect solar energy.
- Other forms of renewable energy besides sunlight get progessively more difficult to maintain. Wind power, for example, is usually not a good solution for individual home owners for two reasons. First, few sites have consistent wind of sufficient force to generate much electricity. Second, wind turbines break down. Whereas solar electric panels have no moving parts, wind turbines by definition move. Those moving parts break, and diagnosing and fixing problems becomes a significant challenge for owners of small-scale wind turbines. In general, properties along the coast and along ridge lines might be suitable for wind installations, but you should do careful research before erecting a tower and turbine. If you do have a good location, you can grid connect and net meter your wind-generated electricity just like solar electricity.
