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US Dept of Energy Study Print E-mail

How did the Ai Dome perform during

the Energy Efficiency Study

prepared for the U.S. Department of Energy?

Superbly. Test findings were released from a year long study prepared for the U.S. Department of Energy by the Florida Solar Energy Center, a governmental consumer agency, in cooperation with the University of Oregon and the University of Central Florida. This study compared an American Ingenuity dome with an energy efficient conventionally built structure and a super energy efficient Styrofoam house designed by Dow Chemical. It came as no surprise to us that our test dome far surpassed both the conventional house and the Dow test house in being the most energy efficient.

Although the test was conducted in a temperate locale (Florida) without summer and winter temperature extremes, the American Ingenuity dome out performed the other structures. In the summer, the energy savings for the dome exceeded 36% and during the winter, the energy savings exceeded 42%. In areas of severe cold and heat, savings would be expected to be considerably higher.

Also, the blower door test showed the dome to be 56% tighter than the conventional test structure and 29% tighter than the Dow house.

To see if air was passing through walls of the dome, tests using infrared were performed. Thermal irregularities in the dome were shown to be insignificant.

Some of the reasons for the American Ingenuity's Dome's super energy efficiency are:

  • Super insulation that does not degrade with time, moisture, or compaction.

  • Spherical shape means reduced exposed surface.

  • Airtight exterior virtually eliminates energy leakage.

  • Solid thermal envelope.

  • Uniform R-value. The insulation is not interrupted with structural members (e.g. 2x4 roof trusses). The only breaks are for doors and windows.

  • Downsized heat and air equipment.

The American Ingenuity Dome kit comes with lifetime R-28 Expanded Bead Polystyrene Insulation (E.P.S.), or if you choose, thicker R-36 E.P.S. insulation is available. In cold climates, you may find that a single ventilating wood stove will provide all the heat your 22' thru 34' in diameter dome home may need.  Larger square footage domes (36', 40', 45' and 48') need a ducting system where the heated or cooled air can be distributed evenly throughout the dome.

Insulation Comparisons:

  • 2x4 solid wood with 3 1/2" fiberglass is about R-8

  • 8" Concrete Block, with 3/4" air, 3/4" Celotex is about R-9

  • 2x6 Solid wood construction with 5 1/2" fiberglass is about R-11

  • 2x4 solid wood with 3" urethane is about R-13

  • 7" E.P.S. insulation is R-28 (standard insulation with the A.I. Dome kit)

  • 9" E.P.S. insulation is R-36 (you can order this thicker insulation for colder climates.)

Have the A.I. Domes won any energy efficiency awards?

  • Yes, our first model (40' and 30' garage) built in 1986 won the Aurora Award for Most Energy Efficient Home in the Southeastern United States and the Grand Aurora Award for the Most Energy Efficient Structure. This dome with standard R-28 insulation beat a passive solar home designed and built by Florida Power & Light, a nuclear powered Florida Utility Company.
  • In 1994 American Ingenuity's office domes, 45' and 34', won the Merit Aurora Award for Most Energy Efficient Commercial Project in the Southeastern United States.
Insulated Concrete Form Buildings Save Energy*

A study, conducted by Dr. Pieter VanderWerf of the Boston School of Management and sponsored by the Portland Cement Association, revealed that homes built with insulating concrete forms (ICFs) consume, on average, 44% less energy to heat and 32% less energy to cool than conventional wood-frame homes.

The study analyzed statistics from 29 ICF homes and 29 wood-frame homes. All of the homes were less than six years old. “We wanted to approach this study as an ‘apples to apples’ comparison,” said VanderWerf, “so we paired each ICF house with a comparable frame house.”

The paired houses were located near each other and were of similar square footage. VanderWerf adjusted the energy consumption of each house to account for differences in size, design, foundation, number of occupants, thermostat setting and HVAC equipment. “We tentatively concluded that these rates of savings should be fairly constant, regardless of location (or local climate),” said VanderWerf.

Although most of the homeowners participating in the study liked there dwellings, regardless of the type of construction, the reasons they gave for their satisfaction were quite different. The ICF homeowners most often cited functional advantages, such as comfort (including evenness of temperature and low air infiltration), sound reduction, energy efficiency, solidity and strength. Several ICF homeowners said they liked their low utility bills. Owners of the wood-frame homes most often cited advantages unrelated to the home’s quality of construction, such as location, floor plan and inclusion of the owner’s preferred features. VanderWerf added that “not many of the owners of frame homes considered it superior construction.”

Superior construction is one of the main reasons for the continuing upsurge of ICF construction in North America over the past several years. PCA market researchers report that in 1994, only 0.1% of new home construction (1,110 homes) was built using ICF. But, researchers predict that by 2000, nearly 7% of all homes built in the country (about 68,000 homes) will use ICF construction.

*Source: Portland Cement Association

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