Drastic reductions in heating, cooling and electricity costs can be accomplished through very simple changes, most of which homeowners can do themselves.
Why make your home more energy efficient? Here are a few good reasons:
• It saves money. It costs less to power a home that has been converted to be more energy-efficient.
• It increases indoor comfort levels.
• It reduces our impact on climate change. Many scientists now believe that excessive energy consumption contributes significantly to global warming.
• It reduces pollution. Conventional power production introduces pollutants that find their way into the air, soil and water supplies.
1. Find better ways to heat and cool your house.
As much as half of the energy used in homes goes toward heating and cooling. The following are a few ways that energy bills can be reduced through adjustments to the heating and cooling systems:
• Install a ceiling fan. Ceiling fans can be used in place of air conditioners, which require a large amount of energy.
• Periodically replace air filters in air conditioners and heaters.
• Set thermostats to an appropriate temperature. Specifically, they should be turned down at night and when no one is home. In most homes, about 2% of the heating bill will be saved for each degree that the thermostat is lowered for at least eight hours each day. Turning down the thermostat from 75° F to 70°F, for example, saves about 10% on heating costs.
• Install a programmable thermostat. A programmable thermostat saves money by allowing heating and cooling appliances to be automatically turned down during times that no one is home and at night. Programmable thermostats contain no mercury and, in some climate zones, can save up to $150 per year in energy costs.
• Install a wood stove or a pellet stove. These are more efficient sources of heat than furnaces.
• At night, curtains drawn over windows will better insulate the room.
2. Install a tankless water heater.Demand water heaters (tankless or instantaneous) provide hot water only as it is needed. They don't produce the standby energy losses associated with storage water heaters, which will save on energy costs. Demand water heaters heat water directly without the use of a storage tank. Therefore, they avoid the standby heat losses required by traditional storage water heaters.
3. Replace incandescent lights.
The average household dedicates 11% of its energy budget to lighting. Traditional incandescent lights convert approximately only 10% of the energy they consume into light, while the rest becomes heat. The use of new lighting technologies, such as light-emitting diodes (LEDs) and compact fluorescent lamps (CFL), can reduce energy use required by lighting by 50% to 75%. Advances in lighting controls offer further energy savings by reducing the amount of time lights are on but not being used. Here are some facts about CFLs and LEDs:
• CFLs use 75% less energy and last about 10 times longer than traditional incandescent bulbs.
• LEDs last even longer than CFLs and consume less energy.
• LEDs have no moving parts and, unlike CFLs, they contain no mercury.
4. Seal and insulate your home.Sealing and insulating your home is one of the most cost-effective ways to make a home more comfortable and energy efficient -– and you can do it yourself. A tightly sealed home can improve comfort and indoor air quality while reducing utility bills.
The following are some common places where leakage may occur:
• electrical outlets;
• mail slots;
• around pipes and wires;
• wall- or window-mounted air conditioners;
• attic hatches;
• fireplace dampers;
• weatherstripping around doors;
• window frames; and
• switch plates.
Because hot air rises, air leaks are most likely to occur in the attic. Homeowners can perform a variety of repairs and maintenance to their attics that save them money on cooling and heating, such as:
• Plug the large holes. Locations in the attic where leakage is most likely to be the greatest are where walls meet the attic floor, behind and under attic knee walls, and in dropped-ceiling areas.
• Seal the small holes. You can easily do this by looking for areas where the insulation is darkened. Darkened insulation is a result of dusty interior air being filtered by insulation before leaking through small holes in the building envelope. In cold weather, you may see frosty areas in the insulation caused by warm, moist air condensing and then freezing as it hits the cold attic air. In warmer weather, you’ll find water staining in these same areas. Use expanding foam or caulk to seal the openings around plumbing vent pipes and electrical wires. Cover the areas with insulation after the caulk is dry.
• Seal up the attic access panel with weatherstripping. You can cut a piece of fiberglass or rigid foam board insulation the same size as the attic hatch and glue it to the back of the attic access panel. If you have pull-down attic stairs or an attic door, these should be sealed in a similar manner.
5. Install efficient shower heads and toilets.
The following systems can be installed to conserve water usage in homes:
• low-flow shower heads. They are available in different flow rates, and some have a pause button which shuts off the water while the bather lathers up;
• low-flow toilets. Toilets consume 30% to 40% of the total water used in homes, making them the biggest water users. Replacing an older 3.5-gallon toilet with a modern, low-flow 1.6-gallon toilet can reduce usage an average of two gallons-per-flush (GPF), saving 12,000 gallons of water per year. Low-flow toilets usually have "1.6 GPF" marked on the bowl behind the seat or inside the tank;
• vacuum-assist toilets. These types of toilets have a vacuum chamber which uses a siphon action to suck air from the trap beneath the bowl, allowing it to quickly fill with water to clear waste. Vacuum toilets are relatively quiet; and
• dual-flush toilets. Dual-flush toilets have been used in Europe and Australia for years, and are now gaining in popularity in the Canada. Dual-flush toilets let you choose between a 1-gallon (or less) flush for liquid waste, and a 1.6-gallon flush for solid waste. Dual-flush 1.6-GPF toilets reduce water consumption by an additional 30%.
6. Use appliances and electronics responsibly.
Appliances and electronics account for about 20% of household energy bills in a typical home. The following are tips that will reduce the required energy of electronics and appliances:
• Refrigerators and freezers should not be located near the stove, dishwasher or heat vents, or exposed to direct sunlight. Exposure to warm areas will force them to use more energy to remain cool.
• Computers should be shut off when not in use. If unattended computers must be left on, their monitors should be shut off. According to some studies, computers account for approximately 3% of all energy consumption.
• Use efficient “Energy Star”-rated appliances and electronics. These devices, approved by the DOE and the Energy Star Program, include TVs, home theater systems, DVD players, CD players, receivers, speakers and more. If just 10% of homes used energy-efficient appliances, it would reduce carbon emissions by the equivalent of 1.7 million acres of trees.
• Chargers, such as those for laptops and cell phones, consume energy when they are plugged in. When they are not connected to electronics, chargers should be unplugged.
• Laptop computers consume considerably less electricity than desktop computers.
7. Install daylighting as an alternative to electrical lighting.Daylighting is the practice of using natural light to illuminate the home's interior. It can be achieved using the following approaches:
• skylights. It’s important that they be double-pane or they may not be cost-effective. Flashing skylights correctly is key to avoiding leaks;
• lightshelves. Light shelves are passive devices designed to bounce light deep into a building. They may be interior or exterior. Light shelves can introduce light into a space up to 2½ times the distance from the floor to the top of the window, and advanced light shelves may introduce four times that amount;
• clerestory windows. Clerestory windows are short, wide windows set high on the wall. Protected from the summer sun by the roof overhang, they allow winter sun to shine through for natural lighting and warmth; and
• light tubes. Light tubes use a special lens designed to amplify low-level light and reduce light intensity from the midday sun. Sunlight is channeled through a tube coated with a highly reflective material, then enters the living space through a diffuser designed to distribute light evenly.
8. Insulate windows and doors.
About one-third of the home's total heat loss usually occurs through windows and doors. The following are ways to reduce energy lost through windows and doors:
• Seal all window edges and cracks with rope caulk. This is the cheapest and simplest option.
• Windows can be weatherstripped with a special lining that is inserted between the window and the frame. For doors, weatherstrip around the whole perimeter to ensure a tight seal when closed. Install quality door sweeps on the bottom of the doors, if they aren't already in place.
• Install storm windows at windows with only single panes. A removable glass frame can be installed over an existing window.
• If existing windows have rotted or damaged wood, cracked glass, missing putty, poorly fitting sashes, or locks that don't work, they should be repaired or replaced.
9. Cook smart.An enormous amount of energy is wasted while cooking. The following recommendations and statistics illustrate less wasteful ways of cooking:
• Convection ovens are more efficient that conventional ovens. They use fans to force hot air to circulate more evenly, thereby allowing food to be cooked at a lower temperature. Convection ovens use approximately 20% less electricity than conventional ovens.
• Microwave ovens consume approximately 80% less energy than conventional ovens.
• Pans should be placed on the correctly-sized heating element or flame.
• Lids make food heat more quickly than pans that do not have lids.
• Pressure cookers reduce cooking time dramatically.
• When using conventional ovens, food should be placed on the top rack. The top rack is hotter and will cook food faster.
10. Change the way you wash your clothes.• Do not use the “half load” setting on your washer. Wait until you have a full load of clothes, as the “half load” setting saves less than half of the water and energy.
• Avoid using high-temperature settings when clothes are not that dirty. Water that is 140 degrees uses far more energy than 103 degrees for a "warm" setting, but 140 degrees isn’t that much better for washing purposes.
• Clean the lint trap before you use the dryer, every time. Not only is excess lint a fire hazard, but it will prolong the amount of time required for your clothes to dry.
• If possible, air-dry your clothes on lines and racks.
• Spin-dry or wring clothes out before putting them into a dryer.
Homeowners who take the initiative to make these changes usually discover that the energy savings are more than worth the effort. Also don’t forget that there are numerous Government initiatives and programs offering rebates and tax incentives for major upgrades to insulation, heating and cooling.
Tuesday, January 26, 2010
Condensation is the accumulation of liquid water on relatively cold surfaces.
Almost all air contains water vapor, As warm air cools, its molecules get closer together and squeeze the tiny vapor droplets closer together. A critical temperature, known as dew point, exists where these water droplets will be forced so close together that they merge into visible liquid in a process called condensation.
Household air is humidified from human and animal exhalation, plant transpiration, and fixtures such as showers and dryers. This humidity can rise significantly higher than outside air. When this humid air meets a cold indoor surfaces condensation can occur. This often happens on single-pane windows because they lack the necessary thermal insulation available to better windows. Double-pane windows have a layer of gas (usually argon or air) trapped between two panes of glass and should be insulated enough to prevent the accumulation of condensation. If this type of window appears misty or foggy, it means that its seal has failed and the window needs to be replaced.
Silica pellets are often contained inside the aluminum perimeter strip of a window to dehumidify incoming household air that was not stopped by the window’s seal. If not for this substance, incoming air could condense on the glass.
Silica gel has an immense surface area, approximately 800 m²/g, which allows it to absorb water vapor for years. Eventually, the silica pellets will become saturated and will no longer be able to prevent condensation from forming. A double-paned window that appears foggy has failed and needs to be repaired or replaced.
Why Double-Paned Windows Fail - Solar (Thermal) Pumping
Although double-paned windows appear to be stable, they actually experience a daily cycle of expansion and contraction caused by “thermal pumping.” Sunlight heats the airspace between the panes and causes the gas there to heat up and pressurize. Expanding gas cannot leave the chamber between the panes and causes the glass to bulge outward during the day and contract at night to accommodate the changing pressures. Over time, the constant pressure fluctuations caused by thermal pumping will stress the seal and challenge its ability to prevent the flow of gas in and out of the window chamber.
Can Failed Windows be Repaired?There are companies that claim to be able to repair misty windows through a process known as “defogging.”
This repair method proceeds in the following order:
1. A hole is drilled into the window, usually from the outside, and a cleaning solution is sprayed into the air chamber.
2. The solution and any other moisture are sucked out through a vacuum.
3. A defogger device is permanently inserted into the hole that will allow the release of moisture during thermal pumping.
There is currently a debate as to whether this process is a suitable repair for windows that have failed or if it merely removes the symptom of this failure. Condensation appears between double-paned windows when the seal is compromised and removal of this water will not fix the seal itself. A window “repaired” in this manner, although absent of condensation, might not provide any additional insulation. This method is still fairly new and opinions about its effectiveness range widely. Regardless, “defogging” certainly allows for cosmetic improvement, which is of some value to homeowners. It also removes any potential damage caused by condensation in the form of mold or rot.
Window condensation will inevitably lead to irreversible physical window damage. This damage can appear in the following two ways:
Riverbedding – Condensed vapor between the glass panes will form droplets that run down the length of the window. Water that descends in this fashion has the tendency to follow narrow paths and carve grooves into the glass surface. These grooves are formed in a process similar to canyon formation.
Silica Haze – Once the silica gel has been saturated, it will be eroded by passing air currents and accumulate as white “snowflakes” on the window surface. It is believed that if this damage is present, the window must be replaced.
In summary, condensation in double-paned windows indicates that the window has failed and needs to be replaced. Condensation, while it can damage windows, is itself a symptom of a lack of integrity of the window’s seal. A failing seal will allow air to transfer in and out of the window even if it is firmly closed