by Steve Andrews
There is no final list that can firmly prioritize potential energy upgrades for all existing homes. Costs for upgrades will vary by age of home, size of home, style of home (one- vs. two-story), type of construction (frame walls vs. masonry walls), and other features. But the list below summarizes a number of energy improvements that have been demonstrated to save some amount of energy
One comment on heating vs. cooling: in the Pueblo area, heating energy requirements outweigh cooling energy requirements by a roughly 5-to-1 ratio. Upgrades to a home’s building shell will tend to not only save energy but improve year-round comfort and resale value.
A few improvements—such as tightening up a home—can have unintended consequences. It can be helpful to engage a professionally trained home energy diagnostician (weatherization specialists, HERS [Home Energy Rating System] raters, etc.) as they are trained to look at a house as a system of interactive parts. By comparison, HVAC and insulation specialists can be very good at what they do but can miss the larger picture and—worst case—can recommend fixes that may be marginal (“you need more insulation” or “you need a larger furnace” when what you really need is to have your ducts sealed).
- No-cost Steps
- Turn your thermostat down at night during the winter, from when you go to bed until you get up the next morning or whenever you’re gone during the day. Studies by utilities show a 5%-8% savings are typical by those homeowners who set back their thermostats.
- Turn down your water heater setting. A water heater operates 24 hours a day, usually keeping 40 or 50 gallons of water at between 120 and 140 deg F. The lower setting is sufficient for nearly all applications, especially since most dishwashers have a water heater booster that can further boost the water temperature when necessary.
- Use ceiling and box fans indoors to delay mechanical cooling. Blowing air directly on a person will give them comfort at a higher indoor air temperature, usually as much as five degrees higher. That means you can delay turning on higher-use mechanical cooling equipment such as an evaporative cooler (aka swamp cooler) or air conditioner.
- Turn off unneeded lights and appliances. If you use compact fluorescent or LED bulbs, this step doesn’t save as much energy as it used to, but turn off lights when you leave a room. Also turn off your computer and TV when not using or watching them.
- Air dry your dishes and clothes. If you have a dishwasher, turn off the electric drying function. Air drying clothes on a clothes line saves energy, helps clothes last longer, and reduces unwanted indoor heat gains during the summer.
- Take showers instead of baths. This normally reduces consumption of hot water plus saves on your water bill.
- Clean your refrigerator’s heat exchange coils (usually underneath the appliance). Do this at least once a year. This saves electricity and reduces summertime cooling requirements, since a fridge with hair/dust-clogged coils generates more heat in your kitchen. (You can think of a fridge as a moderate sized heater; the dirtier the coils, the longer the heater operates, and the more it costs to cool your food and the more it heats your kitchen—useful in winter but counter-productive during the cooling season.)
- Open windows at night during the summer once the outdoor temperature is lower than the indoors, and then close windows back up in the morning once the outdoor temperature climbs above the indoor temperature. (Note: this approach comes with potential home security issues that need to be addressed.)
- Low-Cost Upgrades
- Change your furnace filter. A dirty furnace filter will reduce the amount of heated or cooled air circulated through your ductwork during the winter and summer, respectively. That can reduce the efficiency of heating and cooling equipment and make the air handler work harder to deliver conditioned air to your home. Changing your furnace filter once a month is a cheap ($1+/-) way to save energy.
- Wrap water heater with insulation, including exposed pipes (both hot and cold lines) for several feet above the tank. This saves energy 24/365. The older the tank, the less insulation it contains and the more you save by insulating the outside.
- Seal exposed ductwork in attics and crawlspace. This can save a large amount of energy during both heating and cooling seasons. Any exposed ductwork in basements should also be sealed. These actions can improve comfort by delivering heated or cooled air where it is intended rather than wherever it leaks out. Use Mastic sealant; it comes in 1-gallon buckets and costs $12 – $15, comes out the consistency of peanut butter and is applied with a disposable 39-cent paint brush. One gallon should be all you need. Alternatively you can use high-quality aluminum tape. Do not use standard duct tape as it fails fairly quickly thus is not worth the effort.
- Seal air leaks in homes. The worst offenders are in attics, crawlspaces and basements. Start by weather-stripping and insulating the top side of your attic hatch. Be sure to look for and cut off air by-passes (or air chases) from the basement or crawl space to the attic. Sealing a house off from a crawl space can be done with no-cost materials, though it may require minor expenditures. There are a variety of types of weather-stripping at hardware stores that can be used to seal off gaps around loose-fitting doors and windows.
- Sheet film over single-glazed windows. During the winter, a home with single-layer glass in the windows can be upgraded seasonally by purchasing plastic film kits and applying the plastic that essentially creates a double-glazed unit. When properly done, this will cut heat loss out windows by 50% at relative low cost. The downside of this approach is that the films may need to be removed from operable windows during the summer to facilitate night-time ventilation (aka “free cooling”).
- Look for Energy Star ratings on all lights, electronics and appliances that you purchase. The slightly higher purchase prices will eventually be paid for by energy savings.
- Moderate Cost Upgrades
- Efficient replacement furnaces and water heaters. Furnaces can last anywhere from 15 to 30 years. When it comes time to replace an old unit, in most homes upgrading to a high-efficiency unit (90% AFUE or better) will normally be paid for by energy savings within 10 years or less, depending on a home’s other energy features. The higher your heating bills, the more this upgrade makes sense.
As each appliance nears the end of its useful life, do a little research so that if the equipment suddenly fails you don’t replace it in such a rush that you don’t purchase the most cost-effective equipment for your application. And if your home’s energy features (walls, ceiling, ducts, house tightness) have been upgraded, it’s quite possible that you should install smaller heating and cooling equipment when you make a new purchase.
- Add some attic insulation. The less insulation you have now—say, two to five inches–the more cost-effective adding attic insulation turns out to be. This step improves comfort year-round and saves energy year-round.
- Add foundation insulation. If your home is built on a slab and you have cold around your floor’s perimeter, digging down a foot and applying rigid over the now-exposed slab will slow heat loss; to make sure the foam doesn’t degrade in the sun, it must be covered with a protective and compatible coating or other product where it is exposed above the dirt.
If you have a basement, the interior can be covered with a vinyl-faced fiberglass blanket. If you are going to finish the basement, batts can be installed in the wood-frame walls. In either case, the full height of the wall should be insulated. If the basement is already finished, an exterior foam option somewhat similar to the slab detail described above can be used.
If you have a crawl space, sidewalls can be insulated with fiberglass blanket insulation or a rigid foam product (if it has a foil facing that gives it a fire rating that allows it to be exposed). If the crawlspace is vented, the frame floor between the crawlspace and living space can be insulated, though it is hard to do this effectively. In the latter case, an option exists to be close off the vents but this requires covering the ground with a vapor retarder such as plastic sheet film; shifting to an unvented or conditioned crawlspace may require consultation with a weatherization specialist or trained Home Energy Rater.
3.4 Add storm windows. This costs less than installing new windows and, if you purchase storm windows with a “hard-coat” low-e coating, they will save roughly the same amount of energy and provide just as much comfort improvement. However, you won’t get as much of the non-energy-savings benefits: improved appearance and higher resale value.
- Higher-End Upgrades to Consider
- Insulate your exterior frame walls. Holes can be drilled either inside through drywall or outside through siding (even through brick joints) and loose-fill insulation is then blown into the cavities. When done properly by a trained installer, this step will significantly improve indoor comfort and save substantial amounts of energy, especially in two-story homes.
- Install replacement windows. Despite the highly-advertised step of replacing windows for saving energy, this approach can almost never be done on the basis of energy savings alone. To justify this investment, one must place considerable value on a) improved comfort (can be a major improvement), b) improved appearance, and c) higher resale value. If your original windows are leaky metal casements with single glass, upgrading to a double-glazed window with a low-e coating will save considerable energy. In the best case, if you have windows that face south, they should be replaced with windows that have a high solar transmission factor (Solar Heat Gain Coefficient of 50%-70%) whereas the windows facing east or west and north should have a lower SHGC (20%-30%); this is called “tuning your windows for solar orientation” to reduce both heating and cooling bills year-round.
- Outsulate your masonry walls. Installing rigid insulation over brick or block walls is expensive but very effective. It should significantly decrease both winter heating and summer cooling requirements. If a home is built with multi-course brick or brick-and-block walls, sheets of rigid foam can be attached to the exterior and then coated with a synthetic stucco. This costs considerably more than filling frame walls with cellulose insulation. The foam should be at least two inches thick; three inches are recommended since the extra inch is a very minor part of the total cost. A benefit of this approach is that the home’s exterior is renovated; the approach is most cost-effective on a masonry home with paint on the exterior that would otherwise needed to be repainted; however, if maintaining the existing brick look is important, the much more complex approach of adding foam and drywall on the interior is a possibility; however, this approach is even more costly.
4.4. Consider adding solar electric panels (PV). While this is a very high-cost item, there are solar tax credits that substantially reduce your initial costs. Additionally, the cost of installing solar systems has decreased substantially over the last 5-6 years.
Realize that the amount of solar energy hitting a rooftop in the Pueblo area is higher than in most other parts of the country. Since residents in the Black Hills and San Isabel Electric territories pay the highest rates for electricity in Colorado, any investment by a homeowner in solar power generation equipment should provide an effective return on your investment. Finally, some solar installers can provide favorable financing such that—between tax credits and offsetting expensive electricity—you may have break-even costs from day one of the installation.
The above list was assembled by retired energy consultant Steve Andrews (10/1/2016).
For more information, visit the following sites.
The site above is sponsored by a Colorado-based non-profit that advocates for and provides assistance to low-income families.
The above site is sponsored by the U.S. Department of Energy and covers a wide range of topics about how to save home energy.
The above site is sponsored by the US Environmental Protection Agency and focuses on energy-efficient appliances.
The above site describes incentives available for Colorado residents investing in energy efficiency upgrades.