03121 Energy Conservation for Homeowners

That which is not good for the bee-hive cannot be good for the bees. — Marcus Aurelius

The importance of household energy conservation.

According to the Union of Concerned Scientists, the operating energy of our housing is one of the top three household contributors to the emissions that drive global climate change. Reducing the operating energy cost of our dwellings is one of the top three lifestyle evolutions they recommend.

If you own your dwelling, you have more freedom to make changes in the building that will reduce its energy and carbon emission footprints. Here are some ideas to reduce the amount of energy required by your dwelling. They can be applied to apartments/condominiums and town homes (terraced housing) as well as to single family dwellings on city lots.

Stop the air leaks. The first thing to do is to find and stop the air leaks. The previous documents of this section have already discussed that process. We used about 90 tubes of caulk and 20 cans of foam to seal every crack and hole we could find in the building envelope of our house, which is a Craftsman bungalow originally built in 1929. We tuck-pointed the exterior brick veneer. In the attic, every place that two pieces of wood came together, we laid a bead of caulk on the seam. This is a relatively inexpensive process that pays major dividends, winter and summer. We used the book Insulate and Weatherize, from Taunton Press, and followed its recommendations literally.

Super-insulate the walls, floor, and attic/ceiling. My rule of thumb is that whatever insulation level works for attics should be used in the walls and the floors too even though the recommendations for walls and floors are always less than attics.

People sometimes justify putting more insulation in the attic than in their walls because they say “heat rises.” While this is true, convection is only one of the three ways that heat moves toward cold. Heat will most certainly move in any direction toward cold. The attic recommendations should be used for the walls and floors. I suspect that the real reason for the present recommendations for wall and floor insulation are the limits of what can be done with conventional 2 x 4 or 2 x 6 stud walls.

How is this possible in existing construction? It’s actually quite simple. First we insulated the existing walls with blown-in cellulose insulation. Then we built new walls, 5-1/2 inches inside of the existing walls, all the way around on our exterior walls. We put dry wall over the frame and blew in more cellulose insulation. We now have 9 inches of cellulose insulation in our walls, giving us R-33, almost double the typical R-19 insulation of a 2 x 4 stud wall.

We ran a bead of caulk around the edges of each piece of dry wall before we put it in place on the wall.

We did not connect the new frame that we built to the exterior walls. Instead, the non-load-bearing frame anchors to the floor and ceiling. This avoids the problem of “thermal breaks,” which are places in your house where there is no insulation.

After we completed our original project, we realized that we needed to insulate the interior walls. At several places, interior walls meet exterior walls, and without insulation in the interior walls, those places are thermal breaks. Insulating the interior walls is part of the floor insulation process since each interior wall occupies a bit of floor foot print.

People sometimes say — “but you lost floor space!” We have 1,548 square feet, and we don’t even notice the missing square feet incorporated into our new walls. We gained beautiful deep window wells and that is a feature that almost everyone who comes to our house remarks about.

Depending on your situation, insulating your floor may be impossible (e.g., if your house is built on a slab). If there is a crawlspace, you could insulate the exterior of the stem wall or you could insulate directly under the floor. If insulating underneath is impossible, you may decide to insulate above your existing floor, by adding insulation on top of the existing floor and building a new floor on top of the insulation. This is probably the least desirable choice, although it may be the only choice in some situations.

It is unfortunate for the whole planet and for our species and all the other critters of this planet that the generations who came before us had such cheap energy prices due to political finagling that they designed their buildings and cities to waste energy.

The world has not been served well by its architects and home builders, who consistently rank profit before ecological reality. Taken as a whole, our entire built environment wastes energy at prodigious rates as a matter of building design! People paid money to construct buildings that operate about as inefficiently as is possible! They paid money so they would have to pay even more money than necessary in operating costs and upkeep.

Ventilate the attic. There are many attic strategies. In our particular case in Oklahoma City, we went with attic ventilation. We have 6 passive turbine ventilators in our attic and a system of soffit vents all the way around the roof overhang. If you have an attic, you need a strategy for it that is consistent with the needs of your climate.

Insulate the windows. We have excellent double-pane, argon filled, low-e coated windows. The problem is that even the best energy efficient window is only the equivalent of an R-3 insulation panel. Since we have R-33 walls, we felt we needed something better than R-3 in our windows. We built insulated interior window shutters for all of our windows.

We used a rigid board insulation and cut pieces to fit our windows.

We duct taped four layers of the insulation board together for each window, creating an R-20 insulated shutter. They are three inches thick.

We covered the shutters with green felt, contact paper, or canvas slip covers. for aesthetic purposes.

The shutters for the north facing windows fit snugly into the window well. The sun never shines through those windows (we have a porch on the north side), so we don’t get any heat from the sun through them during the winter. On the east and west sides of the house, where we want sun during the winter when its shining, we put the shutters on rails so that they can slide back and forth. In the summer, we keep them closed during the day and open them at night.

If you want to avoid using foam, which has environmental issues in its manufacture, you could build wooden boxes sized to cover or fit into your windows and fill them with cellulose insulation. Cellulose has less insulating value than foam, so you would need to make them thicker to get to the R-20 insulation value.

For the south side of the house, where we have large floor to ceiling windows in a passive solar sunspace, we made large shutters, 4' x 8', that are R-20. We enclosed them in canvas slip covers. During the winter, we take them down during the day and put them up at night. During the summer, we put them up during the day and take them down at night. When not in use, they stack at one end of the sun porch.

Yes, it takes a minimal amount of work every day to operate the shutters. It’s not much and it helps keep heat in during the winter and keep heat out during the summer. After several years, the task is so well integrated into our household routine that we barely even notice the work.

Take advantage of passive solar. Our house is not an ideal site for passive solar. Its long axis is north — south. East-west is the ideal orientation for passive solar. (I got the property before I began learning about these issues.) When you have lemons, you can always make lemonade and that is what we have done.

We took the south wall off of our old utility room and installed double pane patio doors as windows. We installed two double-hung windows that would open for ventilation purposes. This is our solar sun porch. We have vents on the north wall of the sun porch into the rest of the house. Every door in the house has a vent above it next to the ceiling. We have vents in the walls that separate the east and west sides of the house (our long axis is north-south) at the ceiling for warm air and at the floor so the cold air can return.

During the winter:

The sun shines into the sun porch, heating the air and the materials of the room.

The heated air rises and the convective loop draws warm air into the house where it circulates.

As it cools it falls and the cooler air returns through door ways and floor vents into the sun porch, where it heats up and the process repeats.

The first winter after we made this change to our house, when I told people we no longer used natural gas for heating, they would ask — “How do you heat your house?” I replied — “Magic.”

If you want to really delve into this, you could calculate the amount of thermal mass necessary to store enough heat from the sun so that you need no back-up heat. Those calculations are beyond the scope of iPermie. There are links in the Additional Resources section to help you get up to speed on this more technical issue.

Manage your hot water situation. Start with a low-flow shower head and faucet aerators. The flow of shower water through our “low-flow” shower is better (more “drenching”) than the water flow of our old wasteful shower head.

We have an electric water heater, so we installed an on-off switch for it. We only turn it on when we need hot water. Electric water heaters are much better insulated than gas water heaters. With five people in the house, we don’t turn it on every day. When we have the funds, we will install a solar hot water heater and the electric tank will simply be a back-up for when the sun doesn’t shine.

Be prudent about what you bring into your house. We don’t have a dish washer nor a garbage disposal. We do have computers and televisions. We plug them into on-off electric plug strips so that we can turn them all the way off when we aren’t watching them. Check the energy consumption of anything electric you bring into your dwelling.

Say No to the electric can opener and yes to the food processor (if you preserve and process food).

Yes to the microwave (if you're not worried about leaking energy), no to the garbage compactor and disposal.

Yes to washing machine (if otherwise you would drive to a laundromat), no to electric or gas dryer. Hang your clothes on a line to dry. If there is a laundry within walking or bike ride of your house, doing your wash at the local laundromat is better than buying a washing machine. In either case, dry the clothes on the line.

These are decisions you make with the members of your household. Do not mindlessly accumulate energy burning junk in your life. Weigh the advantages versus the disadvantages of each. Be intentional about your energy usage.

Lighting. Compact florescent lights are the low-hanging fruit of the lighting conservation tree. The newest frontier, however, are the LED lights, which are even more energy conservative than compact fluorescents. Their price at this time is high. As production increases, the prices will decline. This is the same consumer curve that compact fluorescent's followed earlier in the 1990s.

Deciduous shade is your friend in the summer. If you own a house on a lot, plant deciduous trees so that they shade your house during the summer. You want deciduous trees — which lose their leaves in the winter — because in the winter, you want the sun to hit your house. In the summer, you want your house to nestle in a nice shady sea of green.

While it takes years to grow trees, vines grow quickly. Plant morning glories for the shade of their leaves and the beauty of their flowers. Plant runner beans for the beauty flowers and the tasty beans.

Paint your roof white. If you have a dark-colored roof, paint it white. The easy and cheap way to do this is to use white wash — which essentially is a solution of water and slaked lime. It will need to be renewed every few years. In the meantime it is an insanely cheap way to change the color of your roof to reflect sunlight. Scientists have crunched the numbers and the advantage of the white roof in the summer outweighs the disadvantage of a white roof in the winter.

Create Buffer Zones between your house’s walls and the environment. The design for our house calls for enclosing the front porch, building an enclosed summer kitchen at the southwest corner of our house (which is the primary entrance used by the residents), and a screened/enclosed porch at the southeast corner of the house.

The front porch will be enclosed during the summer with window screen. When winter comes, we will put up storm windows. This creates a buffer zone between the north wall and the rest of the environment. It will lessen the impact of north winds blowing on that wall.

The summer kitchen at the southwest corner will be screened in the summer and have storm windows for the winter. This creates a winter air lock entrance for the house and expands the passive solar sun porch.

The enclosed porch at the southeast corner of the house as screens for the summer and storm windows for the winter. During the winter this creates an extension to the passive solar sun porch.

Unlike the sun porch itself, the southwest and southeast extensions will not be insulated. They will buffer the west and east walls of the sun porch, and the south walls of two rooms from the exterior environment.. They will be “low mass sun spaces” which will heat up during the day, providing heat for the inside environment. They will cool down at night. This is fine since there are super-insulated walls between these two sunspaces and the rest of the house.

Use efficient heating and air conditioning equipment. One of the exceptions to avoiding new stuff is when you replace heating and AC equipment. New equipment is much more energy conservative than older equipment.

Before you immediately decide on central heating and air, you should investigate zone heating. Instead of cooling or heating your whole house, with zone heating you cool or heat only the areas that people occupy. If you have followed these recommendations and super-insulated your house for your climate, you will find this easier to do.

The capital equipment for zone heating and cooling is much less expensive than central air or heat pumps. We use the smallest size of window AC (5000 BTU) that retail for about $99 and portable oil-filled electric heaters that retail for about $60-70. We have not bought expensive but highly efficient equipment like ground or air source heat pumps.

If you can afford the capital expense, ground source heat pumps are the most efficient central heating and air system available. A ground source system may not need repairs often, but if something goes wrong with the buried pipes, repairs can be expensive. A variation on this theme is the air source heat pump. Air source have lower capital costs than ground source heat pumps, but they may have higher operating and maintenance costs.

Solar Heating. Solar air heaters work like solar water heaters, only they heat air instead of water. Ventilating with the warmed air from solar air heaters is an earth-friendly way of staying warm in the winter.

Hydronic heating systems, which use hot water to provide heating, can be combined with solar hot water heating.

See http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm for ideas and plans for solar air heaters.

District Heating. As we develop ideas like neighborhood service centers, it will become possible to take advantage of some efficiencies of scale for heating and cooling homes. Typically using hot and chilled water, a district heating system provides the businesses and residences in a geographic area with heating and cooling services. This may be one of the most energy conservative methods of providing home climate conditioning services. Europe uses solar thermal techniques with district heating. A district heating service could be operated by a neighborhood cooperative owned by the persons benefitting from the service.

Solar PV. Solar PV systems make a lot of sense for home-owners who have invested time and effort in demand destruction by behavior changes, insulation and weatherization, and installing efficient HVAC systems. Most utilities allow situations where the your electric meter actually runs backwards as the solar cells generate electricity. They will buy any excess power that you generate from you at a wholesale price. While most people won't sell much energy to the utility, by offsetting your power usage with solar PV, you can save a considerable amount of money and avoid carbon emissions.

Passive House Movement. This is a new school in home design that aims for low costs per square foot for energy use. This option is more fully developed in Europe, where governments have heavily taxed energy as a way of discouraging energy gluttony. This is one reason why Europe operates a high civilization with about half the energy consumption of the United States. It has seven basic principles:

Superinsulate. Eliminate thermal bridges (places where building elements are not insulated and thus provide an easy path to lose heat in the winter or gain it in the summer). Make it airtight. Specify energy- or heat-recovery ventilation. Specify high-performance windows and doors. Optimize passive solar and internal-heat gains. Model energy gains and losses using the Passive House Planning Package, or PHPP.

http://www.eco-logic.info/pub/Principles-of-Passive-House-Design-Part-I

http://www.eco-logic.info/pub/Principles-of-Passive-House-Design-Part-II

The passive house goal for total energy consumption is 120 kwh per square meter. Our house is at 106% of this standard.

More information about the passive house retrofit standard is at —

http://solaroregon.org/workshops-and-education/tours/goal-net-zero-2010/passive-house-talk-outline-tad-everhart .

http://www.passiv.de/en/03_certification/02_certification_buildings/04_enerphit/04_enerphit.htm

http://www.viking-house.ie/passive-house-retrofit.html