We answer Frequently Asked Questions from our customers to help you control costs and stay comfortable year round.
Learn what different energy ratings mean, the systems we recommend, and more.
Learn how a high-energy surge protection device can protect electronics and appliances from electrical surges, and what to know before purchasing a surge protector.
The correct way to protect electrical devices against surges is by making sure you use a properly designed surge protector that provides protection for the electrical conductors plugged into it. A computer with a network connection must have a surge protector designed to protect the electrical connection as well as the telephone circuit and network cable. Be sure to match the surge protector to the job you’re asking it to do.
Yes, they do. Just as electronic equipment can be damaged by large voltage surges, so can refrigerators.
To properly protect your sensitive electronic equipment you must construct a barrier around it much like you would put a fence around your home. Since you usually can’t prevent the things like lightning that damage your home electronics, you must keep these conditions from getting to your important equipment. Every piece of electrical equipment in your home needs a barrier. Just as it would be silly to dead bolt your front door, then leave the windows wide open, the same is true of your electrical equipment. Every avenue to the outside world must be protected—power, phone, cable, data and control lines must all be protected or your equipment will be vulnerable to damage.
Begin power protection at the main power entrance, the point where your power, cable and phone lines enter the house. By installing a high-energy surge protection device at this location, you can knock down the first wave of high voltage spikes entering your home. Most contractors call these lightning arrestors. But, don’t confuse these devices with a lightning rod. Lightning rods are installed to protect the house from physical damage in case of a direct hit. They won’t protect electrical equipment inside the home. The lightning arrestor is a device that helps divert damaging surges away from your electrical system and out through your ground rod. The cable TV line will probably enter your home near the main power entrance as well. It’s best to have all of your utilities enter your home at one point because it allows you to tie all of their ground rods together to form a single grounding system. This is required by some codes but it’s often overlooked by cable installers. Unless all of your equipment ties into a single ground, protection against surges won’t be as effective. Moving inside your home, the television, DVD, DVR, CD player and stereo system represent a considerable investment, and they can be easily damaged by spikes. Each should be plugged into a plug-in surge protector. Use a protector that has multiple outlets allowing one device to protect your entire entertainment center. If you have cable service, the lead into the house should be surge-protected as well. Everything should be protected. If you protect your stereo but leave the CD player unprotected, the connection between the two devices provides a path for spikes. Some appliances containing electronic controls (i.e. microwave ovens) may also require surge protection. Make sure you use a surge protector designed for “heavy duty use”. There are surge protectors designed especially for microwaves. Telephones and answering machines are some of the most commonly damaged devices in the home. A plug-in surge suppressor should be used to protect the power and phone line inputs. A common mistake is protecting only the power line. This does not provide adequate protection. Using a device that contains both protection elements in a single package is best and ensures system compatibility. These devices will have inputs for the phone line and the electric plug. If either line goes directly to the equipment, the equipment is not completely protected. To prevent the flashing “12:00″ problem, look for clocks and DVD players with built-in battery back-up. Battery back-ups are not designed to keep the unit operating during a power outage, but it will preserve the memory and settings so they will still be there when the power comes back on.
The UL Mark on a product means that UL, an independent safety science laboratory, has tested and evaluated the product and determined that it meets UL requirements. At aajogo, we recommend that the surge protection chosen for an electrical supply be listed by UL under the UL 1449 listing. UL provides the voltage that the surge protection device lets pass through under the UL test. For a 120 volt application, we suggest you choose a surge protector with a UL listing less than 500 volts.
We recommend four features: one, indicator lights to show that the device is working and not damaged; two, thermal fusing to reduce the possibility of fire should the surge suppressor fail; three, protection against short circuits by either fuses or circuit breakers; and four, that it’s constructed of quality materials.
Surge Protectors listed under UL 1449 must meet more demanding standards. The requirements include: Thermal fuse protection, catastrophic overvoltage protection, ability to survive higher transient currents, and protection against shocks after the device fails. Look for a label that states “Listed TVSS” or is marked as “Transient Voltage Surge Suppressor.”
Surge protectors degrade over time. This is because the majority of surge protectors rely on a metal oxide varistor, or MOV, to work. MOVs only conduct electricity if and when the power level reaches an excessive level. That excess power is rerouted automatically to the ground wire, which safely dissipates the excess electricity into the ground. But over time, MOVs degrade. That’s why it’s good to buy a model with a failure indicator. And some models come with an automatic cutoff or auto shut-off safeguard. These models cut off power to the surge protector if and when the MOV has degraded to the point where it can no longer adequately protect any connected equipment.
Before purchasing surge protectors, you should conduct an inventory of your sensitive equipment. This inventory is simply a walk through your home to determine where and what type of sensitive equipment you have. Go room by room listing each piece of electrical equipment. Note whether or not the device is connected to the outside world in any other way besides the power line, like telephone lines, modems or antennas. You’ll also want to note whether items can be grouped to share a multiple outlet device. Then sit down with your list and determine which of the items you want to protect, and make a corresponding surge protector shopping list. Pay special attention to the units that will require cable or phone protection in addition to power protection. Surge suppressors are available at electronics stores, home stores, discount stores, department stores, computer stores or by mail order. You’re most likely to find educated sales help in computer and electronics stores.
Consider only those products that are UL listed as transient voltage surge suppressors (TVSS). Any number of products will have UL labels listing them as multiple outlet devices. This does not mean the product is a UL-listed surge suppressor. One of the most important performance characteristics of a surge protector is its “clamping voltage.” This is the voltage the surge suppressor passes through to your equipment before diverting to ground. The lowest clamping voltage recognized by UL is 330 volts or .33 kilovolts. The product’s clamping voltage will be listed on the product next to the UL label if it is UL listed. Select only those plug-in protection devices with a 330-volt clamping voltage. Some manufacturers list very low clamping voltages on their label or in their product literature. View this information for what it really is—marketing hype. Always use the UL number as your purchasing guide. Over time all surge suppressors will wear out. Most will provide years of service under normal conditions. However, it’s important to know when the product fails. Look for products with indicator lights, audible alarms or power disconnect as a failure warning. Without one of these you could be unprotected without knowing it.
While surge protectors won’t prevent lightning from striking your house, they will protect your appliances and home electronics from being damaged by momentary electrical spikes and surges.
A good ground connection is essential to the safe, reliable operation of any piece of electrical equipment in the home. Electrical grounding ensures that if there is ever a short on a piece of electrical equipment, current will flow through the ground system and trip a breaker or blow a fuse, thereby providing protection from injury or electrocution. Grounding also is the primary path through which a surge protector dissipates energy from an electrical spike. A ground system’s ability to dissipate electricity is measured in ohms. The NEC (National Electric Code) Article 250 calls for a ground system of 25 ohms or less with 0 ohms being the unattainable but theoretical “perfect ground.” Properly installed ground rods achieve the 25 ohm requirement. Equally important is that all wires and pipes entering the house be bonded to a single ground point. This means the electrical, cable TV, water and telephone phone systems should all be connected with electrical conductors. Separate ground rods for phone or cable, that are not connected to the electrical ground rod are unsafe and probably a violation of the local electrical code. If you have a ground rod installed, be sure it tests to less than 25 ohms. If you have a ground rod and the cable or phone lines are not bonded to it, call aajogo today to check your system.
Understand the costs associated, options available to you and product details and cleanup guidelines for your energy efficiency lighting investments.
Uniformity is a measure of how evenly or “smoothly“ the lighting level is spread out over an area. It is expressed as a uniformity ratio of average foot-candles divided by the minimum allowable foot-candles. The lower this ratio, the better.
The U.S. Department of Energy (DOE) states that, “In 2007, Congress passed the bi-partisan Energy Independence and Security Act (EISA), which included new, higher efficiency standards for the basic light bulbs we use today (think of the Edison light bulb). Beginning in January 2012, these new standards required these bulbs to be roughly 25%* more efficient. That is, they were required to consume less electricity (measured in watts) for the amount of light produced (measured in lumens).
“Using light bulbs that comply to EISA’s standards could save consumers nearly $6 billion in 2015. In your own home, upgrading 15 inefficient incandescent bulbs could save you about $50 per year.”
* Source: EnergySavers.gov
Lighting accounts for 10%* of the total energy use in the average home in the United States and costs between $50 and $150* per year in electricity. Although that is not much money compared to the cost of operating heating and cooling equipment, it is enough to justify making some efficiency modifications. Also, because it is such a visible energy user, it’s a good place to start teaching kids to be mindful of wasting energy.
* Source: ENERGY STAR® -www.energystar.gov
The Department of Energy (DOE) estimates that by 2030, solid-state lighting (SSL), which is much more energy efficient and longer lasting, could reduce the annual U.S. electricity consumption by about 25 % (when compared to a scenario with no SSL on the market)–enough energy to illuminate 95 million U.S. homes. An emerging clean energy technology, SSL uses various forms of light-emitting diodes as illumination sources. SSL is expected to make a significant energy and environmental impact over the course of the next decade. By 2025, the DOE’s SSL Core Technology Research and Product Development SSL R&D Program hopes to have advanced solid-state lighting technologies that are much “more energy efficient, longer lasting, and cost-competitive” than conventional lighting technologies.
Lighting facades and landscapes adds beauty and attracts attention. Since these types of lighting fixtures are typically hidden from view, it makes sense to choose less expensive—yet sturdy—fixtures. For maintenance purposes, mount the fixtures so they can be accessed easily. And angling the light upward will reduce glare and bring out the textures of your home and landscape elements. Where possible, invest in energy-efficient outdoor lighting and fixtures.
Each CFL (compact fluorescent light) bulb, on average, contains 4 mg of mercury. If a CFL should break in your home, the U.S. Environmental Protection Agency (EPA) provides cleanup guidelines that can be performed by the general public.
Review the Cleanup Guidelines
According to the U.S. Department of Energy (DOE), “an ENERGY STAR® qualified CFL lasts up to 10 times longer than a traditional incandescent bulb that puts out the same amount of light. An ENERGY STAR® qualified LED bulb will last as much as 25 times longer than a comparable traditional incandescent bulb.”
* Source: ENERGY STAR® -www.energystar.gov
CFLs contain a small amount of mercury and should be disposed of properly, ideally by recycling. aajogo has partnered with The Home Depot to offer recycling for compact fluorescent light bulbs at the retailer’s stores in Georgia. For more information about the CFL recycling program, visit www.ecooptions.homedepot.com. aajogo sponsors in-store bins at all 88 The Home Depot locations in the state, which creates the state’s most widespread recycling program for CFLs.
To find a location of The Home Depot near you, visit www.homedepot.com/StoreFinder, or search for other locations to recycle your CFLs on www.lamprecycle.org.
Our expert shows you the benefits of cooking with electric energy vs. gas and explains what to look for when shopping for energy efficient appliances.
Most customers discover that electric cooking is less expensive. The gas bill for cooking goes to $0 when you use electric equipment, and the overall energy bill stays the same or goes down because of a reduced load on air-conditioning units.
No, electric cooking is more efficient than gas cooking. That’s because more heat is absorbed by food cooked on electric equipment than food cooked on gas. That conclusion was reached by using an equation* that measures efficiency: the amount of heat energy (British Thermal Units or “BTUs”) that are consumed by the cooking process divided by the amount of heat absorbed by the food and then multiplying that number by 100. Food cooked on electric equipment “out-scored” food cooked on gas equipment.
* Source: University of Minnesota, 1984
Electric. Conduction is the best form of heat transfer, and electric has quicker heat transfer than gas, so electric is faster to preheat.
Unless you’re using an open burner range or a wok range, electric cooking is faster.
Learn how heaters and air conditioners work and the steps you can take to ensure that your systems work as efficiently as possible.
Yes. Waste-heat recovery devices, sometimes called hot gas reclaim systems, take heat where it is unwanted—from your air conditioner’s or heat pump’s outdoor heat rejection coil—and move it where it is needed, to your hot water tank. In so doing, these devices can decrease water heating costs substantially while also lowering air conditioning costs. It may sound too good to be true, but it works well, particularly in hot climates. In areas that have high cooling loads and a long cooling season, enough heat may be reclaimed to meet the home’s entire hot water requirements during the summer months. With a heat recovery device, your air conditioner operates more efficiently because it does not have to work as hard exchanging its waste heat, and the heat deposited in the water heater is essentially free. With the heat recovery device in place, a typical house air conditioner or heat pump produces about 25 gallons of water per hour heated to 130°F. Since heat can be reclaimed only while the air conditioner is operating, the storage tank must have supplemental heating capabilities for when the air conditioner is not on. Even when it does not meet the entire demand, reclaimed heat contributes some heat that would otherwise have to be supplied by the water heater. Heat recovery devices can be installed during construction or retrofitted to existing water heater storage tanks. Most are enclosed in metal cases and mounted either on a wall outside near the air conditioner condenser or inside near the water heater. Ask your service technician or your utility representative about the availability and performance of heat recovery devices in your area.
Yes. A programmable thermostat automatically adjusts your home’s temperature to your schedule, so you’re comfortable when at home and saving energy while away or sleeping. A programmable thermostat could be a good idea if you’re away from home on a regular basis, or want to automatically lower your energy use at night.
It saves energy while you’re away or asleep, and then brings your home’s temperature back to whatever level you desire by the time you return or wake up in the morning.
If you’re heating and cooling your home with an energy-efficient heat pump, a programmable thermostat will help you get maximum energy efficiency. Ask your heating and cooling dealer to install a programmable thermostat, and make sure it’s the type specially designed for your heat pump.
Unless you are a qualified heating and cooling system professional, we do not recommend it. To ensure efficient operation and adherence to regulations, your duct system should be designed and installed by an accredited technician using industry-recognized procedures.
A heat pump works like an air conditioner during the summer and reverses to become an air heater during the winter. In the summer months, refrigerant is piped through the indoor coils, absorbs heat from the room air, and vaporizes. The cooled room air is then re-circulated throughout the house by a blower. The vaporized refrigerant flows into the compressor, which pumps the refrigerant to the outdoor coil, where it condenses back into a liquid by releasing its heat to the outdoor air. Air is circulated through the outside unit by a fan. The cooled refrigerant then flows back to the indoor coil, where the heat transfer cycle is repeated. In the heating mode, the refrigerant flow is reversed, bringing heat inside from outdoors, essentially working like a conventional air conditioner in reverse. Cold refrigerant is piped through the outdoor coils, absorbing heat from the outside air. The refrigerant vaporizes and flows into the compressor, which pumps it to the indoor coil, where it condenses back into a liquid by releasing its heat to the indoor air. The refrigerant then flows back to the outdoor coils, where the heat transfer cycle starts again.
Like refrigerators, most heat pumps have defrost cycles that minimize frost buildup on the evaporator during the winter heating cycle. Defrost occurs automatically at pre-set time intervals. Defrosting works against the efficiency of the unit when it switches into defrost mode unnecessarily, wasting heating and cooling capacity. Microprocessor controls in some units prevent this from happening. Some controls even determine whether the heat pump or back-up heat is more economical at a particular outdoor air temperature and switch to that heating system.
Refrigeration units, commonly known as air conditioners, are mechanical systems that remove heat and moisture from the air by passing it over a cold surface. When warm, moist inside air is blown across the surface of the unit’s cooling coil, the air temperature drops and the water vapor in it condenses making the air cooler and drier and therefore more comfortable. When the outside air is above 75°F, mechanical refrigeration is usually required to lower the inside temperature and humidity to make people feel comfortable. Refrigerating air for comfort inside the home, called air conditioning, is far more complicated than heating. Instead of using energy to create heat, air conditioners use energy to remove heat. The most common air conditioning systems use what is known as a vapor-compression cycle, similar to the one used by a refrigerator.
The primary difference is a refrigerator moves heat out of its interior and releases it to the surroundings, usually the kitchen, while air conditioners take heat from inside the house and release it to the outside environment. Home air conditioners have compressors outside containing a fluid refrigerant, usually R-22. This refrigerant fluid can change back and forth between liquid and gas states at temperatures in the 40 to 50°F range. Just like water when it boils, as the refrigerant changes from a liquid to a gas, it absorbs heat, and when it changes back from a gas to a liquid, it releases heat. By changing state, refrigerants move heat from one place to another.
To understand condensation, one must first understand a couple of other concepts. Humidity refers to the amount of water vapor in the air. Relative humidity is a measure of the amount of water vapor in the air compared to the maximum amount possible at a given temperature. Air with a relative humidity of 50% is holding half the total amount of water vapor it is capable of holding at that temperature. The amount of water vapor that air can hold depends on the temperature of the air. If the air temperature decreases, the maximum amount of water vapor the air can hold is reduced. If air at 70°F and 50% relative humidity is cooled to 52°F, the relative humidity will reach 100% and condensation will begin. The “dew point” is the temperature at which air saturation occurs, and condensation begins. If air at 100% humidity is cooled, condensation will form as fog in the air or on surfaces at or below this temperature. This phenomenon may be observed on a cold winter day when you “see your breath” in the air; your warm breath is cooled enough to condense part of its water vapor, producing the tiny water droplets as fog. A similar process occurs when an air-water vapor mixture flows through walls and ceilings of a home. The air is cooled as it moves through the thickness of the building envelope. When moisture-laden air reaches its dew point, condensation will occur if it is cooled to a lower temperature. The dew point for a given temperature of air from the home varies according to the amount of humidity in that household air. If the dew point is above 32°F, condensation will form as a liquid. If the dew point is colder than 32°F, the water vapor will condense and immediately form frost or snow.
The advantages of ductless split-systems over room and central air-conditioners are: easy installation, quiet operation, versatility in zoning and design, and security. The split systems also eliminate the loss of cool air as it passes through the ductwork. A key advantage of split systems is their ease of installation. Hook-up requires only a three-inch hole (7.62 centimeters) in the wall for the conduit. Unlike with central air conditioning, you do not need ductwork. Since the compressor in most ductless split-systems is as much as 50 feet (15.24 meters) away from the indoor evaporator, it is usually possible to cool rooms on the front side of the house, while still hiding the compressor in a less conspicuous area. The compressor units also fit well on flat rooftops.
Ductless split-system air-conditioners operate relatively quietly, since the compressor is outside and the evaporator unit’s fan generally runs at a low speed. Variable speed high-efficiency fans are also available. By providing zone cooling, ductless split-system air-conditioners save energy, since only the rooms that are occupied need to be cooled. A thermostat independently controls each zone. Therefore, operating costs are often lower than those of central systems that cool every room, whether it is in use or not. If you cannot afford to purchase an air conditioner for the whole house, you can also buy the system one zone at a time. A single outdoor unit controls from one to four zones, depending on the size of the unit. When compared to other add-on systems, split-systems also provide better interior design options. The air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also widely available. Most indoor units are low-profile models, no more than seven inches (17.78 centimeters) deep, and come with decorative jackets. Most newer models come with a remote control unit as standard equipment. This allows the positioning of air-handling units high on a wall or suspended from a ceiling, without compromising convenience. Unsecured room air-conditioners provide an easy entrance for intruders. Split- systems are more secure than window units since there is only a small hole in the wall.
Geothermal heating and cooling offers the highest efficiency, greatest comfort, longest equipment life and lowest maintenance of any system available. Their advantages include:
* Source: Energy.gov
Everyone knows it’s cooler underground in the summer and warmer underground in the winter. Geothermal systems take advantage of the earth’s constant temperatures to provide the highest efficiency available today. Special plastic piping is buried below the ground’s surface which allows heat to be transferred to and from the earth. Water is simply re- circulated to and from the underground piping where it is warmed by the earth in the winter and cooled by the earth in the summer. In order for any system to work properly, it must be sized, designed and installed correctly. Make sure your contractor is manufacturer-certified to install closed loop Geothermal systems.
A home’s supply and return ducts are designed to be in balance, meaning that the amount of air supplied to the home is the same as the amount returned to the air handler, and the pressure inside the house is neutral. If either the supply or return ducts have air leaks, this balance is disrupted and the entire house pressure can be skewed. Studies show this pressure imbalance can increase infiltration up to 200% when the forced-air system operates. Most homes have leaks in the return ducts. And since most return ducts are located outside the conditioned space in the crawl space, basement, or attic, these leaks draw in outside air. This excess air increases the pressure in the home which forces conditioned air outside through cracks. The outside air drawn into the return ducts is hotter in summer and colder in winter than room air, so comfort drops and energy costs rise. Even when return ducts are located inside the house, they can draw in outside air. Often these ducts are hidden from view inside wall, floor, or ceiling cavities, but are not sealed.
If the supply ducts leak, then conditioned air is lost to the outside. Supply leaks create a negative pressure in the building which draws in outside air. This air, too, can be unhealthy and increases energy and moisture problems. Homes usually have a combination of supply and return leaks as well as other duct problems. As a result, one area of the home may have a positive pressure while another has a negative pressure. While pressure imbalances inside a home are bad, partially correcting duct leakage can also pose a risk. For example, equal supply and return leaks can balance each other such that the pressure in a home remains neutral. Sealing only some of the leaks can create a pressure imbalance. Of particular concern to human health is the quality of air drawn into the building by a leaky return duct. If a return duct leak is near a flue or chimney, it can draw combustion by-products into the house. Fixing return leaks without sealing supply leaks can also create an unsafe pressure imbalance. The best course is to ensure that both supply and return leaks are sealed and that the pressure inside the house is neutral.
The best way to reduce the need for cooling during the hot summer months is by keeping the sun out of the home. Begin as far away from the house as possible with shade trees, trellises covered with vines, or awnings. Pay particular attention to east and west facing windows. The sun is low in the sky as it rises and sets allowing its rays to penetrate deep inside the home and making it tricky to keep out. When allowed to enter the home through windows, this solar radiation can cause the inside temperature to rise as much as 20°F on a hot day. The most effective way to shade the home’s east and west windows and walls is to plant tall trees or plant vines on horizontal trellises. Be sure to use deciduous trees and vines because their leaves provide shade in summer, but they drop them in winter when the solar gain is appreciated. Awnings wider than the windows can provide shade, but even they are ineffective when the sun is very low in the sky and can enter the home right under the awnings. To further protect the home, whenever possible, locate porches and garages on east and west walls for additional shading. Shading large areas that can either reflect or retain and reradiate heat into the home like concrete patios and driveways is also helpful. Most homes have roof overhangs that sufficiently shade the windows. When replacing windows, it is preferable to look for high-performance windows with low-E glazing. They look perfectly clear, yet block out a large percentage of unwanted solar radiation. As you move closer to the home, measures tend to become less effective and more expensive to install. Inside the home, solar gain through windows can be reduced by installing drapes with light-colored linings or blinds that can reflect sunlight. Vertical blinds are particularly effective on east- and west-facing windows. Also, choosing lighter colors for roofs and walls to reflect sunlight will reduce heat gain.
The major difference between a furnace and a boiler is the medium used to distribute heat. Boilers use water or steam, while furnaces use warm air. Furnaces can heat the air with any number of sources, but the most common are gas, oil and electricity. There are two primary types of hot air systems: gravity and forced air. In gravity systems, the air travels upward naturally because it is lighter than the surrounding cooler denser air. It travels through ducts into the home.
Forced air systems accomplish the same task, but use a fan to push the air. They also allow more flexibility than other systems. For one thing, humidifiers can be placed in the system to add moisture to the air and cooling units can be added to distribute cool air. If you’re considering adding a cooling system to an existing forced air furnace, note that larger ducts are required for cooling than for heating. This is because there is less of a temperature difference in cold air so the system needs to move more air.
The most advanced and efficient heating and cooling system available today, a heat pump is the most economical way to keep your home comfortable year-round. The technologically advanced heat pump keeps your home warm in the winter and cool in the summer—with one amazing piece of equipment. It’s also a wise energy investment that can result in major savings on monthly energy bills for many homeowners. You also can’t beat a heat pump for durability. In fact, heat pumps last an average of 20 years in the Southeast United States.
Heat pumps also provide added design flexibility when building a home. Since there are no flames or fumes, you won’t have to add flues or vent pipes that waste valuable closet and storage space. And because there are no flues, you’ll have more choices in where to locate the indoor part of your heat pump system.
First, a thermostat calls for heat which signals the heating system to activate. In an electric furnace, this starts the flow of electricity to the heating elements. Unlike gas, oil and other fuel-based systems, electric furnaces have no combustion by-products and therefore require no chimneys or vents. The same air that passes over the heating elements moves directly into the home.
When the temperature of the air that has just passed through the heat exchanger reaches a pre-set temperature, usually between 90 and 120°F, a thermostat in what is called the plenum activates the blower fan. The blower fan draws air across the heat exchanger warming it and distributing the warmed air to the home. When the room thermostat is satisfied, it deactivates the heat source shutting off the electricity to the heating elements. The furnace blower will continue to operate until the air temperature in the plenum drops to the fan switch-off setting. The furnace will remain off until the room thermostat once again calls for heat.
Ductwork carries the air heated in the plenum to the room vents. Cold air return vents are usually near the bottom of interior walls to provide more uniform temperatures. They should be as far from the supply vents as possible.
Understand the benefits of energy efficient home improvements, including smart investments in energy-saving products and simple repairs that can yield big savings.
Your team at aajogo can run rate analyses that compare your usage against available rates and help you decide the rate that’s best for your home. Contact us for more details.
Yes. Homeowners enjoy four major benefits from energy-efficient construction: lower utility bills, increased comfort, higher resale value and qualification for energy-efficient mortgages. Let’s look briefly at each. Lower utility bills are the result of higher construction standards as compared to conventional construction. Increased comfort is because energy-efficient construction techniques virtually eliminate drafts and temperature gradients that make homeowners feel warmer or colder than they really are. Higher resale value results from better constructed, more energy-efficient homes being worth more in the marketplace. A recent survey found that 85% of the respondents believe energy saving features add to a home’s resale value.
Finally, the possibility of qualifying for an energy efficient mortgage is a real advantage. Home buyers purchasing an energy-efficient home with energy consumption that can be documented may qualify for a larger mortgage than they would receive on a conventional home. According to the National Association of Realtors, lenders are now looking closely at the projected utility costs for a home in determining whether a prospective mortgagor can afford both the monthly mortgage payment and the utility payment. In addition, the Federal Home Loan Mortgage Corporation (Freddie Mac) and the Federal National Mortgage Association (Fannie Mae) have changed their appraisal forms to include energy efficiency. Finally, Freddie Mac has changed its purchasing guidelines to permit higher loan-to-income ratios for energy-efficient properties.
The bottom line is more prospective homeowners can qualify for these Energy Efficient Mortgages on an energy-efficient home when lenders examine their ability to repay the mortgage.
Part of life cycle cost analysis, SIR stands for “savings to investment ratio,” and is a relative measure of cost-effectiveness. SIR represents the ratio of savings to investment. In terms of “net present value,” SIR would be the present value cost savings divided by the present value investment—accounting for additional operation and maintenance costs. Any alternative, when compared to the base case—the present value—that has an SIR greater than one is considered economically justified.
An energy investment’s simple payback period is the amount of time it will take to recover the initial investment in energy savings, dividing initial installed cost by the annual energy cost savings. For example, an energy-saving measure that costs $5,000 and saves $2,500 per year has a simple payback of 5000 divided by 2500, or two years. While simple payback is easy to compute, its weakness is that it fails to factor in the time value of money, inflation, project lifetime or operation and maintenance costs. To take these factors into account, a more detailed life-cycle cost analysis must be performed. Simple payback is useful for making ball-park estimates of how long it will take to recoup an initial investment.
Federal law requires that EnergyGuide labels be placed on all new refrigerators, freezers, water heaters, dishwashers, clothes washers, room air conditioners, central air conditioners, heat pumps, furnaces and boilers. These labels are bright yellow with black lettering. EnergyGuide labels for major appliances feature the estimated annual energy consumption, in kilowatt-hours per year (electric) or therms per year (gas). The estimated yearly operating cost is provided toward the bottom of the label. Each label provides the following information:
The labels showing estimated annual energy consumption also show estimated annual operating costs, near the bottom of the label. This estimated cost is based on recent national average prices of electricity and/or natural gas, and assumes typical operating characteristics. New furnaces and boilers must now carry EnergyGuide labels showing their annual fuel utilization efficiency (AFUE); past labels for this equipment only offered suggestions for conserving energy. EnergyGuide labels on heating and cooling equipment still refer customers to manufacturer’s fact sheets available from the seller or installer. These fact sheets give further information about the efficiency and operating costs of the equipment under consideration. EnergyGuide labels are not required on kitchen ranges, microwave ovens, clothes dryers, demand-type water heaters, portable space heaters and lights.
The most common heat pump efficiency measurement is called the Coefficient of Performance, or COP. COP is the ratio of the heat pump’s BTU (British Thermal Unit) heat output to the BTU electrical input. Conventional electric resistance heaters have a COP of 1.0. This means it takes one watt of electricity to deliver the heat equivalent of one watt. Air-source heat pumps generally have COPs ranging from 2 to 4; they deliver two to four times more energy than they consume. Water and ground source heat pumps normally have COPs somewhere between 3 and 5. The COP of air-source heat pumps decrease as the outside temperature drops. Therefore, two COP ratings are usually given for a system: one at 47°F and the other at 17°F. When comparing COPs, make sure ratings are based on the same outside air temperature. COPs for ground- and water-source heat pumps don’t vary as much because ground and water temperatures are more constant than air temperatures. While comparing COPs is helpful, it doesn’t tell the whole story. When the outside temperature drops below 40°F, the outdoor coils of a heat pump must be defrosted periodically. It’s actually possible for the outdoor coil temperature to be below freezing when a heat pump is in the heating cycle. Under these conditions, any moisture in the air will freeze on the surface of the cold coil. Eventually the frost could build up enough to keep air from passing over the coil and the coil would then lose efficiency. When the coil efficiency is reduced enough to appreciably affect system capacity, the frost must be eliminated. To defrost the coils, the heat pump reverses its cycle and moves heat from the house to the outdoor coil to melt the ice. This reduces the average COP significantly. Some units have an energy saving feature that will allow the unit to defrost only when necessary. Others will go into a defrost cycle at set intervals whenever the unit is in the heating mode.
The cooling efficiency measurement for heat pumps is the Energy Efficiency Ratio or EER. This is the same rating system used for air conditioners. EER is the number of BTUs (British Thermal Units) of cooling provided per watt of electrical energy consumed. The energy includes electricity used for indoor and outdoor fans and the compressor. Although similar to COP (Coefficient of Performance), EER is calculated using different units of measure. EER ratings higher than 13 are the most desirable. COP and EER measurements are based on laboratory tests and do not necessarily measure how the heat pump performs in real life. A heat pump’s performance will vary depending on the weather and how much supplementary heat is actually required. Therefore, a more realistic measurement, especially for air-to-air heat pumps, is calculated on a seasonal basis that would include cooling and heating. This efficiency measure is the Heating Season Performance Factor (HSPF) for the heating cycle and the Seasonal Energy Efficiency Ratio (SEER) for the cooling cycle.
Agency (EPA), ENERGY STAR® is designed to help everyone save money while protecting the environment through energy-efficient practices and products. According to the DOE, “Americans, with the help of ENERGY STAR®, saved enough energy in 2010 alone to avoid greenhouse gas emissions equivalent to those from 33 million cars—all while saving nearly $18 billion on their utility bills.”
The Heating Season Performance Factor, or HSPF, can be thought of as the “average COP” for an entire heating season. HSPF is calculated by taking the total annual heating requirements, including all energy inputs (defrost and back-up heating energy included) divided by the total electric power used. The industry standard rating system compares BTUs (British Thermal Units) of heat output to watts of electrical energy input. Since there are 3.4 BTUs per watt of electricity, an HSPF of 7.7 corresponds roughly with an average COP of 2.3. An HSPF of 7.7 or greater is required by the code.
Renewable energy is energy harnessed from or generated by naturally replenishing resources, such as sunlight, wind, rain, tides and geothermal heat.
The Seasonal Energy Efficiency Ratio, or SEER, is the total cooling of the heat pump in BTUs (British Thermal Units) divided by the total electrical energy input in watt-hours during the same period. Naturally, the SEER for a unit will vary depending on where in the country it is located. A SEER of 13 or greater is required by the Department of Energy (DOE).
Solar electricity is energy converted directly from the sun into electricity. This conversion is done through solar cells, also known as photovoltaic or PV cells. PV modules are made up of individual PV cells and are joined together to form a PV array, which is used to generate electricity. The PV array is installed on a roof or in a sunny location to maximize the sun’s rays. When the sun shines on the array, the sun’s energy is converted into electric current that can be used to operate appliances and other household devices.
Once installed, a photovoltaic system requires little maintenance and can produce power for more than 20 years.
The principle behind solar thermal technologies is the same one often used to brew tea in a jar outside on a hot summer day. The sun’s energy radiates to the earth and is captured in a jar of water. The water is warmed by this captured energy, and brews the tea. In the same manner, solar thermal energy can be used to heat water for household use. A solar water heating system requires collectors (“the jar”) to absorb the sun’s energy and a storage system to hold the energy until it is needed. The collectors are large, flat panels that are most frequently mounted on a roof. The storage systems look and act like conventional water heaters. Pumps are also part of the system and are used to circulate the heated water. A residential solar water heating system is usually designed to meet 50-80% of a home’s water heating requirements. Water heating typically accounts for about 14-25% of the average home’s utility bill.
An Act to move the United States toward greater energy independence and security, to increase the production of clean renewable fuels, to protect consumers, to increase the efficiency of products, buildings, and vehicles, to promote research on and deploy greenhouse gas capture and storage options, and to improve the energy performance of the Federal Government, and for other purposes.
The purpose of an energy audit is to identify places in the home where energy is being wasted and prioritize the actions needed to fix them. The end result is intended to reduce the amount of energy the home needs to operate and keep occupants comfortable. Energy audits range from simple walk-throughs you can do yourself to more elaborate services performed by trained professionals. Which is right for you will depend on your situation, abilities and interest level.
If you own the home, there is a clearly defined benefit for your efforts. You’ll start saving money on your energy bills as soon as you identify and fix energy wasters. If you rent or lease, it’s a good idea to check with your landlord early on to see if the audit findings can be acted on. A landlord who pays the utility bills is more likely to invest in the process knowing that there will be savings through lower utility bills down the road. If you are a tenant and pay the utility bills yourself, you’ll benefit immediately from no-cost and low-cost measures uncovered by an energy audit. Improvements requiring an investment in the building itself or its systems should be carefully evaluated since you don’t own them and won’t be taking them with you if you move to another property. The Internet has brought consumers many new conveniences and tools, including help evaluating your home’s energy use. Online calculators let you enter information about your home and appliances and compute your energy costs. Such calculators can be helpful as part of an overall energy plan to help you analyze your best savings opportunities. If you’d like to conduct a free in-home energy audit or online energy checkup, aajogo can help.
Most people make energy investment decisions based on installed cost and expected savings. Unfortunately, these are not as simple to predict as they might first appear. Cost estimates depend on the caliber of materials, quality of the contractor selected, and many design details. Savings for a combination of energy efficiency usually measures less than for each measure taken individually. And certain decisions require a fairly elaborate consideration of local weather and weather variability. Therefore, always check cost and savings estimates from several sources before making your final decision. For example, you might contact a aajogo representative, your service technician and equipment suppliers or contractors to estimate the likely costs and savings associated with making energy improvements to your home. Consider having a BPI Assessment done on your home by a aajogo Program Participating Contractor. Taking advantage of aajogo’s free in-home energy audit can help you determine where and how you can make the most cost-effective, energy-saving and improvements.
Find out more about conducting a Free In-Home Energy Audit or Online Energy Checkup
Life cost analysis is a way of looking at the total cost of ownership of an appliance or home upgrade, as opposed to the initial investment or purchase price. Life costs include the impacts of inflation, the time-value of money and operating costs, such as fuel, in addition to the purchase price. For example, in selecting between two similar new refrigerators, one costing $600 and another costing $550, your initial reaction might be to purchase the less expensive model and save $50. However, by reading the EnergyGuide label, you notice that the first refrigerator costs $68 per year to operate, and the less expensive one costs $80—or $12 more per year. So, is it worth $50 initially to save $12 per year in operating costs? Earning $12 per year on an investment of $50 equates to a return-on-investment of 24% ($12/$50), much better than banks would offer. Sometimes calculating life costs is not so easy. You may not know exactly how much a measure will cost or save and will therefore have to make estimates. To calculate the life cost of an electric appliance, you need the initial cost, the cost of energy, the annual operating costs, estimated lifetime of the appliance in years and the discount factor. Discount factors adjust for inflation and the fact that a dollar today has more value than a dollar spent in the future because it could be invested earning interest over time. This information is entered into the following equation to estimate life cost: LCC = price + (annual energy cost x estimated life x discount factor)
Low-E or “low-emissivity” glazing improves home energy efficiency year-round. During warm weather, long-wave infrared radiation from outside is blocked from passing through the glass. This reduces the interior cooling load. During cold months, long-wave infrared radiation from inside the home is reflected back into the conditioned space. This lowers heat loss through the glass.
You can be sure you’re purchasing the right-size ceiling fan by measuring your room area (length times width) and looking for a fan with the appropriate fan diameter:
Room Area (sq. ft.) = Minimum Fan Diameter (inches)
Some ceiling fans offer reversible operation; they can blow down in summer when the breeze will create a cooling effect, and up in winter to circulate warm air that has risen to the ceiling. This feature is particularly advantageous in rooms with high ceilings that trap warm air during the heating season.
An electric water heater can save you money and offer you benefits that gas water heating just can’t match.
* Based on a family of four, with the following daily water heating schedule: 4 showers, 1 load of clothes, 1 load of dishes and 10 hand washes.
Yes. Ceiling fans move air across the surface of the skin, thereby making people feel up to six degrees cooler. Increase your thermostat’s setting by two degrees and use your fan to lower energy costs by up to 8% over the course of the air conditioning season. While operating, losses from the motor actually heat the space in which they run; therefore, they should only be on when someone is there to appreciate their cooling effect. When no one is in the room, keep ceiling fans off. Ceiling fans are usually mounted at the center of the room where the light fixture would normally go. For this reason, they often contain their own lighting fixture just below the fan blades. It is important to keep lighting below the blades because lights above them will appear to flicker psychedelically when the fan operates. If you own or purchase a fan with a lighting fixture, optimize its efficiency by using ENERGY STAR®-qualified compact fluorescent light bulbs (CFLs). They consume three-quarters less electricity, generate 75%* less heat and last up to 10 times longer than standard incandescent lighting.
* Source: ENERGY STAR® -www.energystar.gov
Learn how proper ventilation can keep your home comfortable and prevent structural damage, plus how to control excessive humidity.
To stay comfortable, there must be some moisture in the air; however, excess moisture can cause problems. Moisture originates both inside and outside the home. The problems it creates can be controlled by minimizing the amount of moisture produced inside the home, reducing the amount of moisture entering structural cavities like walls or attics—either from inside or outside of the home—and ventilating moisture-producing areas such a kitchens, baths and laundries. Reducing the amount of moisture produced in the home is the first defense against moisture problems. This entails locating the major sources of moisture and where possible, decreasing their intensity. An average family of four produces 18 to 20 pints of moisture a day performing routine household activities. Just breathing produces between 8 and 12 pints in 24 hours, cooking adds another 5, showering another half pint per shower, and watering plants adds about the same amount of moisture to the air as is poured on the plants. Limiting non-essential moisture producing activities will reduce the amount of humidity in the home. If the home has humidifiers, they can be reduced in output or turned off, and the number of indoor plants can be reduced. Minimizing the amount of moisture entering structural cavities means separating them from both inside and outside moisture sources. Vapor barriers should create a moisture tight seal around the home’s interior. Bare earth floors of cellars or crawl spaces should be covered with a sheet of .4 mil or thicker polyethylene. Overlap the sheets and secure them in place with a brick or sand. Basement floors and walls that get damp may need a waterproofing treatment. A dehumidifier may be used in these areas. Good attic and crawl space ventilation is essential to keep moisture from accumulating in these areas. Some well-intentioned home owners seal attic and crawl space vents thinking they are reducing heat loss through these openings. While some heat loss may be prevented, considerable damage can result from the trapped moisture. In well-insulated homes, there should not be much heat to be saved in these areas anyway. Ventilate moisture producing areas when moisture producing activities are performed. Kitchen and bathroom exhaust fans should be run during cooking or showering, and exhaust vents, including those for clothes dryers, should be vented outdoors and not into attics or other unconditioned areas.
An early indication of high humidity levels in your home is condensation on windows. Because they are usually the coldest surface exposed to room air, they fog up first. By taking action to reduce condensation on windows, you should be able to avoid condensation problems from occurring inside the walls. Occasional condensation or frost on windows is normal. Frequent occurrences, or periods of prolonged duration, are warnings that inside humidity conditions may be causing condensation inside wall cavities. A musty odor or buildup of mold in the house is another sign of high humidity levels. Inexpensive color-change relative humidity indicators can also reveal high moisture levels. These should be installed near the thermostat. On a positive note, a certain amount of humidity in the home can help prevent dry throats and make people generally feel more comfortable because less moisture evaporates from the body thereby reducing the cooling effect. Also, higher humidity levels results in less static electricity and improved furniture maintenance as wood moisture is maintained reducing cracking and shrinkage.
Proper ventilation controls heat and moisture buildup in attic, crawl space and uninsulated wall cavities. Good ventilation helps cool the house during hot weather and helps prevent structural damage caused by condensation in winter. Ventilation in attics and crawl spaces should not be blocked to reduce heat loss. Such blockages trap heat and moisture that can cause severe damage to the home’s structure.
An air-to-air heat exchanger is the most common type of heat recovery ventilator. An air-to-air heat exchanger consists of two fans and a heat exchanger core enclosed in a box that is usually attached to both supply and exhaust ductwork. One fan expels indoor air while the other draws in outside air. Inside the heat exchanger both air streams pass through a lattice of small air passages made of metal, plastic, or even treated paper. The air streams do not mix, but travel through adjacent passages. In winter, the warmth of exhausted air is transferred to the cold incoming air, while in summer, the coolness of the air conditioned exhaust air reduces the temperature of the hot incoming air. Air-to-air heat exchangers are usually found in fairly tight houses. Most are used in northern climates for heat recovery in the winter, where they recover as much as 80% of the heat from the outgoing air.
People are generally comfortable in homes when relative humidity ranges between 30-60%. Below 30%, some people experience dryness in their nose and throat; over 60%, the air begins to feel uncomfortably sticky. Human comfort is one consideration for indoor humidity levels; the other major consideration is keeping condensation from occurring on interior surfaces and within structural cavities like exterior walls. Excess moisture in these areas can cause problems from peeling paint, cracking of siding, deterioration of building materials and insulation. On the home’s interior, moisture can promote mildew formation and contribute to health problems. Other disadvantages of high humidity include the growth of mold, odors becoming more noticeable, and staining when condensation occurs on windows and around nails or screws in walls and ceilings. In addition, high humidity can worsen respiratory problems for people with asthma or allergies.
Amid growing concern about the quality of the outdoor air we breathe, many homeowners have become concerned about the quality of the air in their homes. The 1970′s alarm about formaldehyde escaping into homes insulated with urea formaldehyde, combined with the 1980′s radon gas scare, have made people wonder what they are breathing in their homes. The contaminants of greatest concern are formaldehyde and other volatile organic compounds (VOCs) found in building materials and consumer products, combustion products from fuel-burning appliances, microscopic organisms and radon. Indoor air pollution can come from building materials, consumer products, pets, pollen, indoor plants, smoking, and, in the case of radon, from the ground.
Experts advise three steps in improving indoor air quality:
Infiltration is uncontrolled air leakage. It is one of the largest and most preventable energy wastes in the home. Infiltration results from a pressure difference forcing air through cracks, holes, and crevices in the home. The pressure difference results from temperature differences between the indoor and outdoor environment, and wind blowing against the side of the home producing a higher pressure than that within the home. Since warm air rises to the top of the home by convection and then leaks out of cracks in the upper walls and roof, it creates a lower pressure in the bottom of the home than outside (causing air to leak in). Another pressure difference is created in the home’s (HVAC) heating, ventilating and air conditioning systems. Infiltration typically occurs around doors and windows, points where dissimilar materials are joined and penetrations through walls, ceilings, and floors for electrical wiring and plumbing fixtures. Another significant source of air leakage is through the home’s ductwork. The best way to begin reducing air infiltration is by knowing where it may be occurring. Studies show that leakage in a typical house mostly occurs through the sills, walls and ceilings. The second largest offender is the windows, closely followed by the home’s (HVAC) heating, ventilation and air conditioning systems. Openings for pipes, doors, vents and wall outlets complete the air leakage pie. Homes with fireplaces look a little different because 14% of their air leakage is related to the fireplace, which slightly reduces the percentage lost from the other areas.
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