Most people don’t know how easy it is to make their homes run on less energy, and here at InterNACHI, we want to change that. Drastic reductions in heating, cooling and electricity costs can be accomplished through very simple changes, most of which homeowners can do themselves. Of course, for homeowners who want their homes to take advantage of the most up-to-date knowledge and systems in home energy-efficiency, InterNACHI energy auditors can perform in-depth testing to find the best energy solutions for your particular home.

Why make your home more energy efficient? Here are a few good reasons:

    * Federal, state, utility and local jurisdictions' financial incentives, such as tax breaks, are very advantageous in most parts of the U.S.
    * 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. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water. As a result, demand water heaters deliver a constant supply of hot water. You don't need to wait for a storage tank to fill up with enough hot water.

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. An InterNACHI energy auditor can be hired to assess envelope leakage and recommend fixes that will dramatically increase comfort and energy savings.

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;
    * baseboards;
    * 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 U.S. 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 U.S. 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 in the United States.
    * Use efficient “Energy Star”-rated appliances and electronics. These devices, approved by the DOE and the EPA’s Energy Star Program, include TVs, home theater systems, DVD players, CD players, receivers, speakers and more. According to the EPA, 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. However, you should consider that inspectors can make this process much easier and perform a more comprehensive assessment of energy saving potential than you can.

What is a Blower Door?
Inspectors should become familiar with blower doors, as they can be a valuable tool in energy audits.

A blower door is a powerful, variable-speed fan that can be temporarily mounted into an exterior door frame to provide controlled air flow for analysis.  The way that air flows through a building can have a serious impact on air quality, comfort and energy expenses.  The use of a blower door allows air flow through a structure, and the resulting loss of heat can be immediately quantified, providing a way to pinpoint the location of air leaks.

Blower doors were originally developed in the 1970s for use as a research tool.  As technology has evolved, allowing for the development of more portable equipment, blower doors have transitioned into use as a valuable field tool, as well.  The first portable blower doors weighed as much as 200 pounds and took up quite a bit of space, and were also very expensive.  Today, they are much more affordable and are built lighter and smaller.  The reduced set-up time allowed by their more compact designs has led to the standard use of blower doors as part of energy audits for measuring air flow.

How It WorksWhen air pressure and air flow are controlled and measured, they can provide data about how airtight a building is.  The three variables involved are pressure, flow and holes or leaks.  A change in one of these factors will produce a change in at least one other factor.  Since the goal of a blower door test is to locate air leaks in the building envelope, data regarding air pressure and flow can provide information about the holes, which may otherwise be tough to find.

The blower door utilizes controlled differences in air pressure to collect data.  Once installed in an exterior door frame, the air pressure inside a building can be changed in relation to the outside pressure by forcing air into or out of the interior.  The difference in pressure forces air through holes or leaks in the building envelope.  The pressure and air flow are measured by gauges, which are part of the blower door equipment.  By measuring the pressure and air flow in relation to each other, the airtightness of the building envelope can be quantified.  The amount of air flow needed to create a change in pressure increases as the airtightness of the building envelope decreases.  A well-sealed building requires less air flow to generate a change in pressure.

Finding the Problems

During a blower door test, the interior air pressure needed to be maintained in order to gather useful data is 50 pascals, which is roughly equal to the pressure created when a 20-mph wind hits the building.  The blower door equipment has a gauge to indicate when this pressure has been achieved, as well as a gauge to indicate the cubic feet per minute (CFM), which is the standard unit of measure for air flow.  Air flow in a well-sealed building will generally be less than 1,500 CFM at 50 pascals.  Air flow above 4,000 CFM would be considered leaky.  This is valuable data that can be acquired in about half an hour with the use of a blower door.

Since the blower door forces air through cracks and holes, the locations of the leaky spots can be identified.  The draft of air entering through the holes can often be felt with the hand.  Smoke and infrared imaging can also be employed to locate smaller, more subtle leaks.  It is often assumed, especially by homeowners, that poorly sealed windows and doors are the major culprits of air leaks.  In reality, leaks in other areas are usually much more significant.  The difference in air pressure between the interior and the exterior is greater both at ground level and up high, so leaks in basements and crawlspaces, as well as in attics, are the most important to locate.

When looking for air leaks, check through basement rim joists, holes for plumbing traps under tubs and showers, cracks between finish flooring and baseboards, utility chases, plumbing vent-pipe penetrations, kitchen soffits, fireplace surrounds, recessed can lights, and cracks between partition top plates and drywall.  These are all common places where significant leaks can develop.

Accounting for Outside FactorsWind and temperature can have an effect on the test data.  Wind blowing on the outside of the building can add to pressure differences between the interior and exterior.  It can also affect the flow rate of the blower fan.  It is best not to conduct blower door tests in windy conditions.  But if wind is not severe, tests can be conducted at multiple points in the building and then averaged together.

Differences in temperature can create differences in pressure.  Accounting for a baseline stack-effect pressure will ensure that the test results are not skewed.  The stack-effect pressure is a function of the height of the building and the difference in temperature from the interior to the exterior.  A 15-foot tall building with a 50º-temperature difference between the inside and outside will have a 5-pascal pressure difference from the top of the building to the bottom.  Some blower door equipment has a gauge with a built-in baseline feature, so this difference can be easily determined at the outset of the test.

Temperature and barometric pressure affect both air density and viscosity, which is its resistance to flow.  Because of this, an adjustment for density is required.  Some software packaged with blower door equipment is designed to make these calculations, and if it is not available during the test, the manual supplied with the equipment should have information about making the necessary adjustments and applying it to the results.

Preparation and Safety

In order to ensure accurate results, as well as safe conditions for performing the test, some preparation is necessary before beginning.  Any fireplaces or stoves used for heating should not be operating, and all furnaces and pilot lights should be turned off.  There should be no open flames anywhere indoors.  Ashes in fireplaces or stoves should be removed so they do not get sucked into the building.  Dampers should be closed.  Every door and window must be closed tightly so that air flowing through them does not affect the test, while all interior doors should be left open.

If there is a basement, it must be determined whether this area is to be considered part of the building envelope for testing purposes.  Generally, if there is heat in the basement, even if only because the furnace is located there, it will be considered part of the envelope, and access to it should be left open during the test.  Sometimes, the test may be done both ways -- with the basement access open and with it closed, and this is quick and simple to accomplish.

Since blower door testing is a standard tool used during an energy audit, it is helpful for inspectors to understand how the test works.  Knowing a bit about the outside factors that can influence the results will ensure that the test is performed correctly.  Setting up the equipment properly will ensure that testers and occupants are safe, and that the testing and results are accurate.

Backdrafting is the reverse flow of gas in the flues of fuel-fired appliances that results in the intrusion of combustion byproducts into the living space. Many fuel-fired water heaters and boilers use household air and lack an induced draft, which makes them especially vulnerable to backdrafting when indoor air pressure becomes unusually low. Inspectors should try to spot evidence of ackdrafting in homes.

 How does backdrafting happen?Fuel-fired water heaters, boilers, wall heaters, and furnaces are designed to exhaust the byproducts of combustion to the outdoors through a flue. These hot gases rise through the flue and exit the home because they are not as dense as indoor air. The pressure differential that allows for the release of combustion gases can be overcome by unusually low indoor air pressure caused by a high rate of expulsion of air into the outdoors through exhaust fans, fireplaces and dryers. When this happens, combustion gases can be sucked back into the house and may potentially harm or kill building occupants. Improperly configured flues or flue blockages can also cause backdrafting.

 How can InterNACHI inspectors test for backdrafting?

 An inspector can release smoke or powder into the draft diverter to see whether it gets sucked into the duct or if it spills back into the room. A smoke pencil or a chemical puffer can be used to safely simulate smoke.  

  An inspector can hold a lighter beside the draft diverter to see whether there is sufficient draft to pull the flame in the direction of the flue.

 Combustion gases that back-draft into a house may leave a dark residue on the top of the water heater. The presence of soot is an indication of backdrafting, although its absence does not guarantee that backdrafting has not happened.

 A carbon monoxide analyzer can be used to test for backdrafting of that gas. Inspectors should be properly trained to use these before they attempt to use one during an actual inspection, primarily to avoid false negatives.  While performing the above-noted tests, it is helpful if inspectors ask their clients to turn on all devices that vent air into the outdoors in order to simulate worst-case conditions. Such devices may be dryers, or bathroom and kitchen fans.Types of fuel-fired water heaters:    Atmospheric Draft Most backdrafting is the result of the characteristics of this type of water heater. Combustion gases rise through the ventilation duct solely by the force of convection, which might not be strong enough to counter the pull from dips in indoor air pressure.

 Induced Draft This system incorporates a fan that creates a controlled draft. The potential for backdrafting is reduced because the induced draft is usually strong enough to overcome any competing pull from an indoor air-pressure drop. 

 Sealed Combustion The combustion and venting systems are completely sealed off from household air. Combustion air is drawn in from the outdoors through a pipe that is designed for that purpose. The potential for backdrafting is nearly eliminated because the rate of ventilation is not influenced by indoor air pressure, and the vented gas has no pathway into the home.

  Water Heater Location The installation of fuel-fired water heaters in particular household locations can increase the chances of personal harm caused by backdrafting. The 2006 edition of the International Residential Code (IRC) states the following concerning improper location:

 Fuel-fired water heaters shall not be installed in a room used as a storage closet. Water heaters located in a bedroom or bathroom shall be installed in a sealed enclosure so that combustion air will not be taken from the living space.

Why is backflow a problem?

Backflow is a potential problem in a water system because it can spread contaminated water back through a distribution system. For example, backflow at uncontrolled cross connections (cross-connections are any actual or potential connection between the public water supply and a source of contamination or pollution) can allow pollutants or contaminants to enter the potable water system. Sickness can result from ingesting water that has been contaminated due to backflow.

Backflow may occur under the following two conditions:

Back-pressure:

    Back-pressure is the reverse from normal flow direction within a piping system as the result of the downstream pressure being higher than the supply pressure. This reduction in supply pressure occurs whenever the amount of water being used exceeds the amount of water being supplied (such as during water-line flushing, fire-fighting, or breaks in water mains).

    back-siphonage:

    Back-siphonage is the reverse from normal flow direction within a piping system that is caused by negative pressure in the supply piping (i.e., the reversal of normal flow in a system caused by a vacuum or partial vacuum within the water supply piping). Back-siphonage can occur when there is a high velocity in a pipe line, when there is a line repair or break that is lower than a service point, or when there is lowered main pressure due to high-water withdrawal rate (such as during fire-fighting or water-main flushing).

Atmospheric Vacuum Breakers

Backflow prevention for residences is most commonly accomplished through the use of atmospheric vacuum breakers (AVBs). AVBs operate by allowing the entry of air into a pipe so that a siphon cannot form. AVBs are bent at 90 degrees and are usually composed of brass. Compared with backflow preventer assembles, AVBs are small, simple and inexpensive devices that require little maintenance or testing. They have long life spans and are suitable for residential purposes such as sprinkler systems. InterNACHI inspectors can check for the following:

    The AVB must be at least 6 inches above any higher point downstream of the device. For this reason, they can never be installed below grade. Even if they are installed 6 inches above grade, inspectors should make sure that they are not installed less than 6 inches above some other point in the system downstream of the device.

    The AVB cannot be installed in an enclosure containing air contaminants. If contaminated air enters the water piping, it can poison the potable water supply.

    A shut-off valve should never be placed downstream of any AVB, as this would result in continuous pressure on the AVB.

    AVBs cannot be subject to continuous pressure for 12 hours in any 24-hour period or they may malfunction.

    Spillage of water from the top of the AVB is an indication that the device has failed and needs to be replaced.

Types of Backflow Preventer Assemblies

Some types of assemblies are common in commercial and agricultural applications but are rare for residential uses. The appropriate type of backflow preventer for any given application will depend on the degree of potential hazard. The primary types of backflow preventers appropriate for use at municipalities and utilities are:

    double check valves:  These are commonly used in elevated tanks and non-toxic boilers. Double check-valve assemblies are effective against backflow caused by back-pressure and back-siphonage and are used to protect the potable water system from low-hazard substances. Double-checks consist of two positive-seating check valves installed as a unit between two tightly closing shut-off valves, and are fitted with testcocks.

    reduced pressure principle assemblies:  These are commonly used in industrial plants, hospitals, morgues, chemical plants, irrigation systems, boilers, and fire sprinkler systems. Reduced pressure principle assemblies (RPs) protect against back-pressure and back-siphonage of pollutants and contaminants. The assembly is comprised of two internally loaded, independently operating check valves with a mechanically independent, hydraulically dependent relief valve between them.

    pressure vacuum breakers:  These are commonly used in industrial plants, cooling towers, laboratories, laundries, swimming pools, lawn sprinkler systems, and fire sprinkler systems. Pressure vacuum breakers use a check valve designed to close with the aid of a spring when water flow stops. Its air-inlet valve opens when the internal pressure is one psi above atmospheric pressure, preventing non-potable water from being siphoned back into the potable system. The assembly includes resilient, seated shut-off valves and testcocks.

 Requirements for Testers and Inspectors

A number of organizations, such as the American Water Works Association (AWWA) and the American Backflow Prevention Association (ABPA) offer certification courses designed to train professionals to test backflow preventers. Requirements for training vary by jurisdiction. Inspection of backflow preventers requires knowledge of installation requirements, although inspectors are not required to become certified.

In summary, backflow preventers are designed to prevent the reverse flow of water in a potable water system. They come in a number of different types, each of which is suited for different purposes.