Building Envelope Forum

Reducing Heat Loss in Residential Construction: The Insulated Electrical Outlet Box

By: Dan Thompson

INTRODUCTION

As energy costs move ever upward, the importance of controlling the flow of heat into and out of residences has become increasingly critical. Insulation materials and techniques have thus improved rapidly to meet the growing demand this cost spiral has spawned. To help in this area, a new technology, the Insulated Electrical Box®, is being patented by a North Carolina firm, IBC, (Insulation Business Consultants), of Brevard.

WHY AMERICA NEEDS THE INSULATED ELECTRICAL BOX®

During the latter part of the 19th century, home heating practices changed in America from space heating to central heating, as technology allowed families to live more comfortably in their dwellings. While the Roman Empire had central heating, called Hypocaust, that technology had been dormant for many years and central heating had not been used extensively until William Baldwin invented the steam radiator and introduced central heating anew.

Even during the time of cheap and abundant energy, people knew it took a lot more energy to heat their dwellings with central heating. Rockwool was accidentally discovered at a volcano in Hawaii and someone noticed that heat didn’t move quickly through the material. Home insulation was thus born and was gradually adopted during the early part of the 20th century starting from the north to the south in accordance with maximum to minimum energy consumption for heat.

As insulation helped with heat loss through attics, people began finding more and more uses for insulation, as well as inventing new types of insulation. Hot water heaters were insulated during the great depression in the United States and for the first time, some people began bathing every day. In the north, people began insulating their walls and the floors over their basements or crawl spaces. Storm windows were introduced and people began to install them in the autumn and remove them in the spring.

Most types of insulation have greatly improved since those times, and double and triple glazing of glass have allowed us to leave the insulating glass installed year round. Building codes now dictate the level of insulation and where it needs to be applied. We have learned much about how air permeates insulation and we have incorporated airtight wraps in our building science. Air is now conditioned all year long as we change from heating during the colder months to air-conditioning during the warmer months.

Still, heat moves like a liquid or gas through holes in the thermal barrier, and while invisible to the naked eye, robs our buildings of conditioned air which wastes our resources and our money. Many people are surprised to learn that our buildings consume more energy than any other facet of our economy, including transportation.

Like the boat builder who cannot design against holes below the water line, we are faced with tremendous energy use to rid the boat of water not suitably restrained, or we need to redesign the hull. Electrical boxes create holes in the thermal barrier of the building. Either we find a way to insulate the area behind the electrical box or we resign ourselves to excessive energy usage in our buildings.

THE INSULATED ELECTRICAL BOX®

Excessive and uncontrolled heat loss occurs at electrical boxes when those boxes are located on exterior walls between the conditioned space inside the home and the unconditioned atmosphere outside of the home. Electrical boxes make holes in the insulating barrier and there is insufficient room behind the box to effectively insulate the cavity behind the box utilizing materials available for the purpose on the jobsite.

Thermal imaging technology allows inspectors to view areas of heat loss through the building envelope and the pictures prove conclusively that in virtually all cases, electrical boxes are a primary means for heat to exit the conditioned space and for unconditioned air to enter the building. Evidence suggests that as much as 20% of all air infiltration in a residence is coming from the electrical boxes.

Besides air transfer, heat loss is occurring due to conduction and convection. While the wall is insulated to R-13 or more, thermal resistance at the electrical box is as low as .003. Heat moves like a liquid or gas. Having 3" X 4" holes in the insulation is rather like having those size holes in the hull of a boat; it takes a lot of energy to keep everything in equilibrium when so much heat is being wasted.

Much work has been done in recent years to address the problem. Energy Design Update recommends face mounted electrical boxes for switches and plugs (November 2007). There are a number of technologies designed to prevent air movement through the electrical box. Carrying the idea forward, a patent has been issued for an enclosure that provides some level of insulation (especially in a 2” X 6" cavity), while also making the box airtight. This technology purports to be Energy Star recognized.

During product development of Custom Formed Batts for Fibertek Corporation, William Daviau, the inventor of The Insulated Electrical Box®, noted that there was no way, on the jobsite, to adequately address heat loss through the boxes. Even the Energy Block provided too little insulation when used in a 2" X 4" cavity. In response he invented and applied for a patent on the "Insulated Electrical Box."

The technology utilizes the same laws of physics that are incorporated into a "Dewar's Flask," which is similar to the technology of a Thermos Bottle. A vacuum or gas filled cavity is manufactured into the side of the box adjacent to the outside wall. The actual insulation ability of the panel is R-13 at .125" thickness and can be increased with additional thickness. The effective R-Value is reduced by conduction of the material at the sides of the panel and overall R-Value must be calculated knowing what that material will be.

Mr. Daviau has also patented a means of sealing the box against air leakage. This technology involves two layers of film encapsulating a gel that air activates to seal the hole where wires penetrate. The film is rugged and the encapsulation is not subject to tearing when secondary work is done to attach the wires to the plug or switch.

BUILDING CODES

Homes in the United States are built in accordance with the International Residential Code, (IRC). That code supersedes the older BOCA, Standard, and Universal Building Codes.

The building code already requires that exterior walls be insulated to various levels of thermal performance which differ somewhat according to climate zones.

No exception is made in the building code for electrical boxes. In accordance with the building code, the area behind the electrical boxes must maintain the thermal barrier. Code officials admit that they haven’t been enforcing this aspect of the building code because they don’t know how to maintain the thermal barrier in such a tight space.

Most code officials do require that foam or fibrous insulation materials be installed behind the box to mitigate the thermal leakage.

Once an insulated electrical box becomes available, there need be no change in codes to compel their usage. When introduced, the existing code language will already mandate them.

ENERGY STAR

Homes built to Energy Star criteria are required to mitigate both air and heat transfer from the conditioned space to the area behind the electrical box.

An Energy Star approved system can be viewed at:
http://www.energyblock.com

This system is normally applied by someone other than the electrician.

Airtight electrical boxes are sometimes achieved by placing a second box around the electrical box such as those manufactured by Lessco. In addition, Nutek, a division of Thomas and Betts, manufactures an airtight electrical box that incorporates a gasket where the electrical box meets the drywall as well as a separate soft foam rubber encasement of the actual box. When a slit is made for wire entry, the foam seals around the wire and prevents air movement through the electrical box.

THE INSULATED ELECTRICAL BOX®

The patent pending technology of the Insulated Electrical Box® incorporates either a very flexible rubber coating over the electrical box, something like a bicycle tube material that closes around the wire, or a double membrane with an adhesive that flows around the wire entry to seal the wire and affix it to the box permanently.

Besides affording a total seal against air leakage, this new design allows for substantial insulation against conductive and radiant heat transfer through the box, which minimizes the effects of convection behind the box.

An important component of the panel behind the newly designed electrical box is the optional radiant barrier that is strategically placed to prevent radiant heat transfer out of the home during the colder months and into the home during the hotter time of the year.

The pictured radiant barrier is actually applied to both sides of the central plate of the insulating panel.

The Insulated Electrical Box® can incorporate as many chambers as may be desirable in the allowable space.

Each chamber of .125” can achieve R-13 through the actual insulated space. Total insulation value will be lower because of conductive heat transfer through the outside walls of the chamber. The actual R-Value will be affected by the choices made for the electrical box walls.

While the chambers might be filled with air, they might also be filled with insulating gases such as argon or krypton or with foams or fibrous insulations. The best insulating qualities are achieved when the chambers contain a vacuum; excellent results are also obtained with a combined vacuum and aerogel, silica, or perlite.

When a vacuum is the insulation medium, getters and desiccants are used to absorb off gassing and moisture in the vacuum area. These components of the core afford a long vacuum life.

The picture above depicts what an Insulated Electrical Box® might look like to the consumer. The pictured box does not have the elastomeric sealing device installed. The sealant will slightly alter the look of the box.

When a wire must gain entry through the rear of the box, a sleeve can be manufactured that allows for the insulation panel to be applied after the wire is inserted. The sleeve will affix to the box by means of clips and the double membrane with adhesive will seal off the opening between the sleeve and the electrical box where the wire enters.

Utilizing the “super insulation” qualities that can be manufactured into the box, it is possible to create a better thermal seal behind the box than that which is available in the rest of the wall assembly.

Even if the insulation is engineered to be marginal, much energy can be saved with little effort.

The radiant barrier which is optional with an Insulated Electrical Box® works best when there are at least two chambers in the insulating panel. For the barrier to work, it must face the side where heat is coming from and there must be some air space between the barrier and where the heat is directed back to whether the heat is coming from the conditioned space or from the outside. The best way is to use two radiant barriers, one facing into the conditioned area to return heat being created for warmth, the second barrier is on the opposite side of the center wall and returns heat from the sun trying to gain entry when the conditioned space is air-conditioned.

An Insulated Electrical Box® might be manufactured using only one insulating chamber and that configuration would be most suitable for colder climates where heat gain is not so much of an issue.

The Insulated Electrical Box® technology is currently available for licensing to manufacturers of electrical boxes.

To license or buy this technology, or for further information, contact William Daviau, the inventor, at 336-601-5911, or email billdaviau@aol.com.

About the Author

Dan Thompson is currently a business consultant, with 24 years experience specializing in cost accounting and cost control formerly with AMF Hatteras Yachts, East Carolina Distributing and BDA Corporations respectively. Mr. Thompson is a 1971 graduate of The University of North Carolina at Greensboro. He has been with Insulation Business Consultants of Brevard North Carolina since its inception in 2006. Dan resides in Ringgold Georgia and can be reached by e-mail at danieljthompson@juno.com


	Reducing Heat Loss in Residential Construction: The Insulated Electrical Outlet Box By: Dan Thompson INTRODUCTION As energy costs move ever upward, the importance of controlling the flow of heat into and out of residences has become increasingly critical. Insulation materials and techniques have thus improved rapidly to meet the growing demand this cost spiral has spawned. To help in this area, a new technology, the Insulated Electrical Box®, is being patented by a North Carolina firm, IBC, (Insulation Business Consultants), of Brevard. WHY AMERICA NEEDS THE INSULATED ELECTRICAL BOX® During the latter part of the 19th century, home heating practices changed in America from space heating to central heating, as technology allowed families to live more comfortably in their dwellings. While the Roman Empire had central heating, called Hypocaust, that technology had been dormant for many years and central heating had not been used extensively until William Baldwin invented the steam radiator and introduced central heating anew. Even during the time of cheap and abundant energy, people knew it took a lot more energy to heat their dwellings with central heating. Rockwool was accidentally discovered at a volcano in Hawaii and someone noticed that heat didn’t move quickly through the material. Home insulation was thus born and was gradually adopted during the early part of the 20th century starting from the north to the south in accordance with maximum to minimum energy consumption for heat. As insulation helped with heat loss through attics, people began finding more and more uses for insulation, as well as inventing new types of insulation. Hot water heaters were insulated during the great depression in the United States and for the first time, some people began bathing every day. In the north, people began insulating their walls and the floors over their basements or crawl spaces. Storm windows were introduced and people began to install them in the autumn and remove them in the spring. Most types of insulation have greatly improved since those times, and double and triple glazing of glass have allowed us to leave the insulating glass installed year round. Building codes now dictate the level of insulation and where it needs to be applied. We have learned much about how air permeates insulation and we have incorporated airtight wraps in our building science. Air is now conditioned all year long as we change from heating during the colder months to air-conditioning during the warmer months. Still, heat moves like a liquid or gas through holes in the thermal barrier, and while invisible to the naked eye, robs our buildings of conditioned air which wastes our resources and our money. Many people are surprised to learn that our buildings consume more energy than any other facet of our economy, including transportation. Like the boat builder who cannot design against holes below the water line, we are faced with tremendous energy use to rid the boat of water not suitably restrained, or we need to redesign the hull. Electrical boxes create holes in the thermal barrier of the building. Either we find a way to insulate the area behind the electrical box or we resign ourselves to excessive energy usage in our buildings. THE INSULATED ELECTRICAL BOX® Excessive and uncontrolled heat loss occurs at electrical boxes when those boxes are located on exterior walls between the conditioned space inside the home and the unconditioned atmosphere outside of the home. Electrical boxes make holes in the insulating barrier and there is insufficient room behind the box to effectively insulate the cavity behind the box utilizing materials available for the purpose on the jobsite. Thermal imaging technology allows inspectors to view areas of heat loss through the building envelope and the pictures prove conclusively that in virtually all cases, electrical boxes are a primary means for heat to exit the conditioned space and for unconditioned air to enter the building. Evidence suggests that as much as 20% of all air infiltration in a residence is coming from the electrical boxes. Besides air transfer, heat loss is occurring due to conduction and convection. While the wall is insulated to R-13 or more, thermal resistance at the electrical box is as low as .003. Heat moves like a liquid or gas. Having 3" X 4" holes in the insulation is rather like having those size holes in the hull of a boat; it takes a lot of energy to keep everything in equilibrium when so much heat is being wasted. Much work has been done in recent years to address the problem. Energy Design Update recommends face mounted electrical boxes for switches and plugs (November 2007). There are a number of technologies designed to prevent air movement through the electrical box. Carrying the idea forward, a patent has been issued for an enclosure that provides some level of insulation (especially in a 2” X 6" cavity), while also making the box airtight. This technology purports to be Energy Star recognized. During product development of Custom Formed Batts for Fibertek Corporation, William Daviau, the inventor of The Insulated Electrical Box®, noted that there was no way, on the jobsite, to adequately address heat loss through the boxes. Even the Energy Block provided too little insulation when used in a 2" X 4" cavity. In response he invented and applied for a patent on the "Insulated Electrical Box." The technology utilizes the same laws of physics that are incorporated into a "Dewar's Flask," which is similar to the technology of a Thermos Bottle. A vacuum or gas filled cavity is manufactured into the side of the box adjacent to the outside wall. The actual insulation ability of the panel is R-13 at .125" thickness and can be increased with additional thickness. The effective R-Value is reduced by conduction of the material at the sides of the panel and overall R-Value must be calculated knowing what that material will be. Mr. Daviau has also patented a means of sealing the box against air leakage. This technology involves two layers of film encapsulating a gel that air activates to seal the hole where wires penetrate. The film is rugged and the encapsulation is not subject to tearing when secondary work is done to attach the wires to the plug or switch. BUILDING CODES Homes in the United States are built in accordance with the International Residential Code, (IRC). That code supersedes the older BOCA, Standard, and Universal Building Codes. The building code already requires that exterior walls be insulated to various levels of thermal performance which differ somewhat according to climate zones. No exception is made in the building code for electrical boxes. In accordance with the building code, the area behind the electrical boxes must maintain the thermal barrier. Code officials admit that they haven’t been enforcing this aspect of the building code because they don’t know how to maintain the thermal barrier in such a tight space. Most code officials do require that foam or fibrous insulation materials be installed behind the box to mitigate the thermal leakage. Once an insulated electrical box becomes available, there need be no change in codes to compel their usage. When introduced, the existing code language will already mandate them. ENERGY STAR Homes built to Energy Star criteria are required to mitigate both air and heat transfer from the conditioned space to the area behind the electrical box. An Energy Star approved system can be viewed at: http://www.energyblock.com This system is normally applied by someone other than the electrician. Airtight electrical boxes are sometimes achieved by placing a second box around the electrical box such as those manufactured by Lessco. In addition, Nutek, a division of Thomas and Betts, manufactures an airtight electrical box that incorporates a gasket where the electrical box meets the drywall as well as a separate soft foam rubber encasement of the actual box. When a slit is made for wire entry, the foam seals around the wire and prevents air movement through the electrical box. THE INSULATED ELECTRICAL BOX® The patent pending technology of the Insulated Electrical Box® incorporates either a very flexible rubber coating over the electrical box, something like a bicycle tube material that closes around the wire, or a double membrane with an adhesive that flows around the wire entry to seal the wire and affix it to the box permanently. Besides affording a total seal against air leakage, this new design allows for substantial insulation against conductive and radiant heat transfer through the box, which minimizes the effects of convection behind the box. An important component of the panel behind the newly designed electrical box is the optional radiant barrier that is strategically placed to prevent radiant heat transfer out of the home during the colder months and into the home during the hotter time of the year. The pictured radiant barrier is actually applied to both sides of the central plate of the insulating panel. The Insulated Electrical Box® can incorporate as many chambers as may be desirable in the allowable space. Each chamber of .125” can achieve R-13 through the actual insulated space. Total insulation value will be lower because of conductive heat transfer through the outside walls of the chamber. The actual R-Value will be affected by the choices made for the electrical box walls. While the chambers might be filled with air, they might also be filled with insulating gases such as argon or krypton or with foams or fibrous insulations. The best insulating qualities are achieved when the chambers contain a vacuum; excellent results are also obtained with a combined vacuum and aerogel, silica, or perlite. When a vacuum is the insulation medium, getters and desiccants are used to absorb off gassing and moisture in the vacuum area. These components of the core afford a long vacuum life. The picture above depicts what an Insulated Electrical Box® might look like to the consumer. The pictured box does not have the elastomeric sealing device installed. The sealant will slightly alter the look of the box. When a wire must gain entry through the rear of the box, a sleeve can be manufactured that allows for the insulation panel to be applied after the wire is inserted. The sleeve will affix to the box by means of clips and the double membrane with adhesive will seal off the opening between the sleeve and the electrical box where the wire enters. Utilizing the “super insulation” qualities that can be manufactured into the box, it is possible to create a better thermal seal behind the box than that which is available in the rest of the wall assembly. Even if the insulation is engineered to be marginal, much energy can be saved with little effort. The radiant barrier which is optional with an Insulated Electrical Box® works best when there are at least two chambers in the insulating panel. For the barrier to work, it must face the side where heat is coming from and there must be some air space between the barrier and where the heat is directed back to whether the heat is coming from the conditioned space or from the outside. The best way is to use two radiant barriers, one facing into the conditioned area to return heat being created for warmth, the second barrier is on the opposite side of the center wall and returns heat from the sun trying to gain entry when the conditioned space is air-conditioned. An Insulated Electrical Box® might be manufactured using only one insulating chamber and that configuration would be most suitable for colder climates where heat gain is not so much of an issue. The Insulated Electrical Box® technology is currently available for licensing to manufacturers of electrical boxes. To license or buy this technology, or for further information, contact William Daviau, the inventor, at 336-601-5911, or email billdaviau@aol.com. About the Author Dan Thompson is currently a business consultant, with 24 years experience specializing in cost accounting and cost control formerly with AMF Hatteras Yachts, East Carolina Distributing and BDA Corporations respectively. Mr. Thompson is a 1971 graduate of The University of North Carolina at Greensboro. He has been with Insulation Business Consultants of Brevard North Carolina since its inception in 2006. Dan resides in Ringgold Georgia and can be reached by e-mail at danieljthompson@juno.com

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