Advantages – Energy Efficiency | AiDomes

Dome sweet dome: Would you live in a dome home?

Maria Sonnenberg, For FLORIDA TODAY Published 1:12 p.m. ET Aug. 22, 2017 

Rockledge builder American Ingenuity makes kits for dome homes, a quirky alternative to a traditional square- or rectangle-shaped house.

Pay attention to Buckminster Fuller and forget the square or rectangle when building a house, and instead go for a geodesic dome.  To view article, click on Florida Today 8.22.17 Story about Aidomes

The forward-thinking Fuller, responsible for giving the name geodesic to the polyhedral dome, championed the dome as the perfect structure for its strength and efficiency. This ideal building form is being created daily in — drum roll, please — Rockledge, home to American Ingenuity, aka Aidomes, builder of dome home kits that are shipped around the world.

Ai founder Michael Busick launched his company in Brevard in 1976. Instead of wood and shingles, which can rot and tear off, concrete, galvanized and expanded polysterene were Busick’s materials of choice for his domes. He was granted a patent for prefab panels that make construction easier than stick-built and can be easily organized into kits that can be assembled by proficient do-it-yourselfers.

You need not sacrifice space with domes. Interior footage with Aidomes ranges from 172-square-feet mini-domes to 2,992-square-foot residences that share the dome’s inherent durability. The Rockledge company’s domes have been erected in 47 states and 15 foreign countries.

“As an architectural form, the dome is one of the strongest built by man,” said Glenda Carlin-Busick, vice president and plans coordinator for American Ingenuity. “The partial sphere (that is a dome) is an aerodynamic shape that is very stable in high winds and can withstand heavy snow loads. Domes greatly exceed the structural requirements of the major building codes in the United States.”

Th Ai domes carry a 225 mph and F4 tornado guarantee and are super energy-efficient.

“Our domes have 30 percent less exterior surface than box-shaped houses and have R28 insulation on the prefab panels with no wood to interrupt the insulation,” Busick.

She noted the electric bill for the company’s 3,700-square foot office of two attached domes averages $72 when the place is kept at 74 degrees during the peak of summer.

The houses are solid as a rock, perfect for whatever Florida weather can throw at it. The concrete construction, reinforced with galvanized mesh and fibers, has no rooftop to blow off in high winds.

One of Ai’s domes went through Hurricane Andrew and a tornado at the same time with no structural damage when the rest of the neighborhood was destroyed,” Busick said.

Builder Ray Vince hopes to tap onto the dome’s excellent efficiency in the community of homes he has planned for Titusville.

The Schoonovers built their geodesic home in Canaveral Groves in 1992. Watch the progress of its construction. The house is now for sale as the couple reaches retirement and looks to move out west. Video by Jessica Saggio and Tim Shortt Wochit

“I had originally thought of going with conventional prefab homes until I discovered that Ai was in Rockledge,” Vince said.

Vince hopes to start his project, aimed to further energize Titusville’s housing market, with a two bedroom/one bath 27-foot dome home that is linked to a 12-foot dome hosting solar panel battery storage.

Throwback:  Unusual homes in Brevard: Dome home

“It will be a super dome home,” said Vince, who is searching for a large parcel of land to build a community of dome homes in North Brevard.

With a price tag of around $160,000, Vince’s dome home is affordable, secure and efficient housing that won’t cost much to maintain.

“He wants to build the dome to be as close to off the grid as possible,” Busick said.

Although structurally very different than traditional houses, domes nevertheless are very cozy inside and are naturals for the open floor plan favored by today’s homeowners.

“Geodesic dome construction translates into a highly comfortable and livable building that has a maximum of floor area enclosed by a minimum of materials,” Busick said. “The building concept of a dome expands the range of simple and economic building options.”

Malcolm and Eva Jewell live in an Aidome on Pineapple Ave. in the Eau Gallie Arts District. The Jewells were not looking for a dome particularly, but the house’s location and its river views sealed the deal. The energy efficiency and strength were just nice bonuses.

More:  This dome home’s for sale. Interested?

“I had known about dome houses and I knew they were very good with hurricanes and wind,” Malcolm Jewell said.

The house is a 34-foot diameter two bedroom/two bath Aidome with 1,171 square feet on two levels. It connected to a 22-foot diameter dome that serves as a one-car garage dome with attic storage.

Settling into dome living for Jewell was a cinch.

“It was surprisingly easy,” she said. “The furniture fits very well.”

About the only drawback in dome living for Jewell is hanging pictures on the outside walls, since their concrete construction makes driving nails something of a bear.

With substantial increases in the cost of construction and energy, dome kits provide significant cost-savings, so expect more to pop up along the Space Coast.

“In the past decade, many people have discovered that the dome design offers a viable solution,” Busick said.

It looks cool, too.

For more on domes, visit aidomes.com.

 

Jamaica 45ft & 34ft Aidomes in Runaway Bay.

Robert Stephens purchased the two Aidomes after the building kits were assembled.  He and his crew beautifully finished the exterior and interior.  The domes will be presented for short term vacation rental and small functions such as intimate weddings with max 80 guests.

The floor plan layouts below were the original design; however the plans have been modified.   A 45′ dome can be designed with three to four bedrooms and 2 1/2 baths.  A 34′ dome can be a garage dome or a two bedroom two bath home.

The Dome building kits are shipped in containers from American Ingenuity’s factory in Rockledge Florida.  One 34′ dome can fit in one 40′ high cube container. One 45′ kit can fit in one 45′ high cube container and one 20′ container.  To obtain shipping quotes, email the receiving port name and Ai will contact a freight forwarder and obtain a shipping quote.  Email address is GlendaB.aidomes@gmail.com

At no cost to you, if you give your property address and building department name,  Ai will call the building department, email them a sample set of plans and find out what is required for them to issue a building permit on the dome.

PDF for Downloading & Printing

Online Viewing – Opens in Browser

34' front solar myrtel

How Can I View an Ai Dome?

American Ingenuity’s Florida office domes (45′ & 34′ of 3,700 sq.ft.) are open for viewing by appointment after 1 pm weekdays.  And once a month, Ai has a Saturday tour of our office domes starting at 11 am.  Please call our office at 321-639-8777 for an appointment.   Click on Tour for info.

New…New ….New interior pictures of finished 48′ dome (five bedrooms) linked to 40′ garage dome in Oklahoma’s tornado alley. To view info about Ai dome and tornadoes click on Tornado.

View pictures of beautiful dome interior designed by international artist Electros, To view pictures of a 45′ dome on full basement review Stroupe page. To view other dome home photos, click on Photos.  American Ingenuity has sold over 800 dome kits into 47 USA states and 14 foreign areas. One of the recent domes to receive a building permit is in Riverside California with the buyer paying $6,500 in shipping costs for one semi-truck to delivery their 48′ in diameter dome kit.  To view assembly pics, click on Banning Ca concrete dome. The homeowner’s wood dome burned in the Silver Fire. They are rebuilding with Ai dome because it has a noncombustible concrete exterior.   Another Aidome was shipped to Trinidad’s rural forested area in January of 2016 with the buyer paying $4,531 in shipping costs.   He chose the Ai dome because its strength resists Trinidad’s hurricane force winds and its exterior is concrete to resist forest fires.

The dome kits American Ingenuity sell become private homes. Ai would like to have model homes throughout the country but it is not economically possible. If Ai did have models, we would need to double the price of the building kit to pay for the model construction, the staff to man them, annual costs to run, pay property taxes, etc. Ai has sold over 800 dome kits throughout the country. The assembled domes don’t belong to us and we can’t extend invitations to see them. However we are very happy that a few dome owners allow us to give out their name and number. So a referral could be a few states away from you.

Our referrals love their domes and are very happy to speak with potential owners. However, since they are not dome sales associates, we promise them that we will speak with each perspective buyer to answer their basic questions and walk them through significant pages on our web site. Ai tries to answer the multitude of potential buyer questions so as to not take up hours of the referral’s time with basic and in depth questions. As a result, please call our office and our friendly staff will be happy to talk with you and later provide a referral. To view free info, click on Info.

For $7 (includes USA mailing costs) purchase a DVD. It shows panel manufacturing, domes under construction and finished domes. Order the DVD by calling our office. Or to view the DVD at no cost, click on New DVD. To view stock floor plans, click on Stock Plans and scroll down the page to click on the hyperlinks. If you do not find a stock floor plan layout to fit your desires, Ai can modify or customize a stock plan or design a custom plan from your sketches and descriptions. If stock plans are mailed, call Ai at 321-639-8777 for printing costs and mailing costs.  To view the sale pricing on the stock plans and the dome kit for each plan, click on Plans & Kit Sale pricing.

To view a Youtube video showing the interior and exterior of an Ai two dome complex for sale in Albuquerque New Mexico, click on Domes. To view a slide show of 45′ dome home with 40′ dome garage, click on Florida Dome Home.

The following covers Utah Concrete AiDomes off Grid at 7500 feet elevation. 

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The Collars chose the American Ingenuity super insulated concrete domes because they are five miles from closest fire station and need to produce their own power for heating. Their area is surrounded by forests that could burn at any time so a noncombustible concrete exterior was a must for their new home.   At the bottom of this page is a pdf containing a four page article that ran in Home Power Magazine describing their domes.

45′ home dome is 2,025 square feet: (1,487 sq.ft. on first floor with 538 sq.ft. on the second floor).  Link of 175 sq.ft. contains utility room and 1/2 bath.  30′ garage dome has 642 sq.ft on first floor with battery & inverter room of 145 sq.ft. –  269 sq.ft of attic storage.

45′ first floor contains 252 sq.ft. master bedroom with 71 sq.ft. closet, 115 sq.ft. bath.  Kitchen is 206 sq.ft. with 70 sq.ft. pantry. Living room 365 sq.ft.  Dining room 200 sq.ft.  45′ second floor contains 150 sq.ft. office, 72 sq.ft. bathroom and 166 sq.ft. guest room. Here are pdfs to view their floor plan layouts.

The following heating recap was written by Mr. Collar in July of 2012.

Inside, the masonry heater (also called a “Russian furnace”) consists of a large masonry firebox topped with a flue internally configured as a maze. Flue gasses exit the top of the lower firebox and travel up and down and back and forth through the flue maze imparting heat into the masonry before going up the stack. The large mass of the firebox/flue stores the heat and radiates it out into the room over a long period. During winter I usually have one fire per day. I fill the firebox very full and light it off between 6:00 and 8:00 in the evening. The fire is not dampered but burns hot and fast so there’s little creosote buildup. The fire dies out between 10:00 and midnight and I close off the air supply and flue dampers for maximum heat retention. In the morning the fireplace masonry is hot to the touch and it simply radiates its stored heat all day keeping the dome comfortably warm. The fireplace is centrally located to maximize heating, extending into the master bedroom. I added two small forced air fans at the top of the firebox to pull even more air over the face and thus increase heat discharge — although I rarely use them.

There are 11 solar water tubes each about a foot in diameter and 8 feet tall placed in a large south-facing window. Originally designed for aquaculture, they are water-filled with waterbed conditioner added for algae control. In the winter the sun warms the water during the daytime. Even with nighttime temperatures below zero, the tubes can reach 85 deg F on a sunny day — especially if there’s snow on the ground to increase the solar radiation effect. At night the tubes re-radiate heat back into the house and I lower the thermal curtain between the tubes and the large window to prevent heat loss back outside. (The thermal curtain is visible in photo 2). I worked with American Ingenuity’s designers to ensure the entryway overhang was sized to shade the tubes during the summer and to provide adequate foundation to handle the extra weight of the water.

The house generally stays comfortable for up to three days without supplemental heat. However, I also have two small propane direct vent wall heaters which are used only when I expect to be gone for more than two days. I’m working on automating the thermal curtain to be able to raise and lower it for daytime solar gain when I’m not at home.

The following was exerted from a July 1998 Home Power magazine: “To power the home they utilized “Photovoltaic array of 32 BP-75 panels supplying an APT3 power center which charges their 2110 Amp-hour Pacific Chloride batteries. This is enough to last them three to five days, depending on usage. Given their ridge top location, they included lightning protection in the APT. A Trace SW4024 sine wave inverter provides clean electrical power with no noticeable line noise. A backup generator is available if needed.” “There average summertime power consumption is between 150 and 200 kWh/month for 2,700 sq.ft. of living space. Wintertime consumption is somewhat higher. For comparison, there average pre-solar usage was near 600 kWh/month in their 2,000 sq.ft. suburban home!”

Download the entire story here in pdf.

Concrete Home & Concrete Garage in South Carolina.  Kolb 40ft Dome Home (three bedroom two bath) with 27ft Dome two car garage.

40′ Dome first floor is 1,271 sq.ft.  2nd floor is 370 sq.ft. For total of 1,641
27′ Garage dome has 550 sq.ft. on first floor & 130 sq.ft. in its attic storage area.

This Geodesic Dome Home built from American Ingenuity’s standard dome kits with R28 insulation is super energy efficient with a low environmental impact.  It has been tested by a third party independent testing company (Home Energy Partners) and was subsequently certified as an ENERGY STAR HOME by EPA. The home actually uses 61 percent less energy than a comparably sized home.  He installed a geothermal cooling & heating system.  Klaus’s 2003 total monthly average energy bill was $49. This includes the electricity and propane costs for his entire 1,600 sq.ft. – 40 ft. dome.

The Energy Star label can only be placed on completed houses. The label cannot go on a Building Kit. Some of American Ingenuity’s clients have had their completed dome homes rated and received the Energy Star label. To find out how your dome home can receive an Energy Star Label, call the EPA Energy Star hot line 1-888-782-7937 and ask for a company in your area that can rate your home.

To view more info about Energy Star and this dome, click on SC Dome Five Star.

To view info and pics about South Carolina dome’s geo thermal heating and cooling system and water furnace, click on GeoThermal.

Online Viewing – Opens in Browser
Kolb Floor Plans 1st Floor
Kolb Floor Plans 2nd Floor

please click on arrows to view the photos.

 

Below is YouTube Video

 

Geothermal in Concrete Home located in Pennsylvania.  This is quote from the 40′ Ai dome owners, Mr. & Mrs. Charles: ““We live in the mountains of PA. The winters up here can be brutal. Our Ai Dome is a 40ft with Link on a 9″ thick livable basement. {Den, Office/Computer room, Kitchenette} The entire interior, to include the mechanical room, is heated and cooled by a GeoThermal, Water furnace, Radiant floor system. Our zone controllers are set on 74 degrees winter and summer. Our sole power source, at present, is the grid. Our costs per month range from $99 to a high of $120. We were amazed that our cost now are less than when we lived in a 14 by 73 ft mobile home while building the Dome. Our decision to build an American Ingenuity Dome home was the best decision we have ever made.”

Below are two items.  The first is a photo gallery containing pics of the dome home.  And at bottom of this page is a  YouTube Video which contains some of the same pictures that are shown in the photo gallery.  Hope you enjoy.

Floor Plans in PDF format.  Open by clicking on the PDF below
or download to your computer by right clicking and saving to your computer.

(your browser may allow you to rotate the picture
by right clicking in the picture after it’s open and selecting rotate)

The following is information provided by Mr. Charles, owner of above 40′ American Ingenuity dome built on a full basement in Pennsylvania.  First floor of dome is 1,286 sq.ft.  Second floor of the dome is 436 sq.ft. for total sq ft in dome of 1,722. The basement square footage is 1,291 making total dome and basement square footage of 3,013.

Our heating/cooling system is a GeoThermal WaterFurnace Synergy 3D and is rated at approx. four ton handling. We have two 500 foot geo loops that are 12 feet underground in a field by the dome.  These fluid circulation loops are piped in and connected to the WaterFurnace and a fluid storage tank. The temperature in the loops stays at around 65 to 69 degrees. The system then calculates, by means of a Hydro Zone controller (mini computer), how many degrees more the fluid needs to be heated to keep the Dome at the temperatures set on each zone thermostat. We have three zones. Main floor zone set at 74, basement zone set at 72 and master bedroom/bathroom zone set at 73 year round. Loft area has no tubing but is never off more than four degrees from the main floor.

The Hydro Zone controller monitors interior and exterior temperature.  It then calculates a tank set point. This set point varies based on exterior temperature and zone thermostat settings. The system then heats the fluid in the tank to that set point and circulates it through the radiant floor tubing. The tubing in the basement is in the concrete floor. the tubing on the main floor was laid down on top of the sub floor. then 3/4″ plywood was form cut to fit between the tubing. A 1/4 inch “luan” surface was installed on top of the tubing and plywood then flooring was installed. Walking on warm floors is absolutely great.

Our power bills this past winter (2013) ranged from $200 to $278 per month.  As cold as it was (many days below zero) and the Dome being totally electric, we are happy with our Dome Home. Many people in this area were over $500 in total energy bills (Electric, propane, coal, fuel oil or combinations)

The Geo Thermal Water Furnace is reset in the summer to operate as a central air system through normal duct work in the Dome. In the summer our monthly power bills range from $99 to $120. the Dome is heated in the winter and cooled in the summer by the same system.

The completed system cost was approx. $27.000. In calculating per year cost against other types of systems this system will pay for itself in energy savings in 8 to 10 years.

Some time ago we had a bad storm and a big tree fell and broke the power lines. It was five days before our power was restored. We had a wood/coal stove put in the Dome as a backup heat source. On the first day we got a fire going and ran the stove for about five hours before bed and let it go out. The Dome stayed comfortable for about three one half to four days before we started the stove again. The outside temperatures were not real cold but a jacket was necessary.

YouTube Video Below

click play button to watch
then click the box in the lower right to enlarge video

The following info covers Collar Dome Heating Info for domes off the Grid.

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Collar 45′ & 30′ Linked Domes in Moab, Utah

at 7,500 feet elevation

The concrete dome kits were purchased in 1996.  The Collars were Do It Yourself builders.  Their off the grid system includes photovoltaics, masory heater fireplace, passive solar water tubes and propane heaters.

The third photo shows the living room including the masonry heater fireplace top/center and the passive solar water tubes in the window on the left. The water tubes are also visible from the outside in photograph one. That’s a water feature over on the far right.

Photo number two shows a typical winter – although recent conditions have led to greater extremes with far less or even more snow.

The following heating recap was written by Mr. Collar in July of 2012.

Inside, the masonry heater (also called a “Russian furnace”) consists of a large masonry firebox topped with a flue internally configured as a maze. Flue gasses exit the top of the lower firebox and travel up and down and back and forth through the flue maze imparting heat into the masonry before going up the stack. The large mass of the firebox/flue stores the heat and radiates it out into the room over a long period. During winter I usually have one fire per day. I fill the firebox very full and light it off between 6:00 and 8:00 in the evening. The fire is not dampered but burns hot and fast so there’s little creosote buildup. The fire dies out between 10:00 and midnight and I close off the air supply and flue dampers for maximum heat retention. In the morning the fireplace masonry is hot to the touch and it simply radiates its stored heat all day keeping the dome comfortably warm. The fireplace is centrally located to maximize heating, extending into the master bedroom. I added two small forced air fans at the top of the firebox to pull even more air over the face and thus increase heat discharge — although I rarely use them.

There are 11 solar water tubes each about a foot in diameter and 8 feet tall placed in a large south-facing window. Originally designed for aquaculture, they are water-filled with waterbed conditioner added for algae control. In the winter the sun warms the water during the daytime. Even with nighttime temperatures below zero, the tubes can reach 85 deg F on a sunny day — especially if there’s snow on the ground to increase the solar radiation effect. At night the tubes re-radiate heat back into the house and I lower the thermal curtain between the tubes and the large window to prevent heat loss back outside. (The thermal curtain is visible in photo 2).  I worked with American Ingenuity’s designers to ensure the entryway overhang was sized to shade the tubes during the summer and to provide adequate foundation to handle the extra weight of the water.

The house generally stays comfortable for up to three days without supplemental heat. However, I also have two small propane direct vent wall heaters which are used only when I expect to be gone for more than two days. I’m working on automating the thermal curtain to be able to raise and lower it for daytime solar gain when I’m not at home.

The following was exerted from a July 1998 Home Power  magazine:  “To power the home they utilized “Photovoltaic array of 32 BP-75 panels supplying an APT3 power center which charges their 2110 Amp-hour Pacific Chloride batteries.  This is enough to last them three to five days, depending on usage. Given their ridge top location, they included lighning protection in the APT.  A Trace SW4024 sine wave inverter provides clean electrical power with no noticeable line noise.  A backup generator is available if needed.”  “There average summertime power consumption is between 150 and 200 kWh/month for 2,700 sq.ft. of living space.  Wintertime consumption is somewhat higher.  For comparison, there average pre-solar usage was near 600 kWh/month in their 2,000 sq.ft. suburban home!”

 

Building Envelope

The following came from the EPA’s web site: 

http://energystar.gov/ia/new_homes/features/VEFraming1-17-01.pdf 

An effective building envelope is a key element for an energy –efficient home.  Value-engineered framing increases the thermal resistance of the building envelope without compromising structural integrity by eliminating unnecessary framing members.  This can result in up to 25 percent reduction in the amount of wood used.  With lumber prices high, optimizing the use of wood can significantly lower the framing cost and reduce the resource impact of new home construction. 

Wood loses or gains heat more quickly than insulation.  In frame construction, studs, joists and rafters are placed at regular intervals throughout the building envelope.  The cavities formed by these framing members are filled with insulation.  The unnecessary use of wood displaces insulation and degrades the thermal efficiency of the building envelope. 

Standard construction practice places framing members at 16 inches on center.  Most building codes allow this spacing to be increased to 24 inches by using deeper framing members (i.e. 2×6’s instead of 2×4’s).  This also reduces labor costs.  

The size and location of doors and windows has an impact on the thermal efficiency of the building envelope.  Figure 1 shows a window opening in standard framed wall.  The location of the window opening requires the installation of additional studs to support the frame.  By utilizing value-engineered framing and adjusting the location of the window opening as shown in Figure 2, unnecessary studs are eliminated. 

At exterior corners and the intersection of interior partitions and exterior walls, additional studs are required to support the drywall.  Figures 3 and 4 show how these studs create pockets that are difficult to insulate and air seal.  By making the modifications shown in Figures 5 and 6, these pockets are eliminated.  Using “drywall stops” can further increase the thermal efficiency at these locations. 

Look for Energy Star labeled homes to include value-engineered framing for improved thermal performance of the building envelope. 

Value-engineered framing can provide many benefits including:

  1. Improved Comfort:  By increasing wall insulation and eliminating air spaces, value-engineered framing increases the overall R-value and integrity of the building envelope.  This results in walls that are warmer in winter and cooler in summer.  This is important because approximately 40 percent of our physical comfort is due to the radiant heat exchange between our bodies and the surrounding interior surfaces.  Value-engineered framing reduces this radiant heat exchange, thus maintaining a more consistent level of comfort throughout a house.
  2. Reduced construction cost:  Value-engineered framing can reduce the amount of lumber and labor needed to construct a home.  This results in construction cost savings.
  3. Lower utility bills:  Value-engineered framing reduces the amount of heat and air that flows through the building envelope.  This results in lower utility bills, making homes less expensive to operate.
The exterior walls and roof of the American Ingenuity dome contain no wood to interrupt the insulation.  The seven inch thick blocks of Expanded Bead Polystyrene that Ai uses is comparable to eleven inches of fiberglass insulation. During the shell kit assembly, a temporary wooden rib system is used to support the component panels until the seams between the panels and all the entryways and dormers are concreted…then the rib system comes down.  There is no wood in the exterior walls and roof of the Ai dome to interrupt the insulation…no wood to burn…no wood to rot and no wood for termites to eat.  The exterior of the Ai dome is steel reinforced concrete that does not contain shingles.
So the Ai dome exterior is a tight envelope because it does not have wood interruping its insulation and the insulation is super-thick; as a result the Ai dome saves its clients 50% to 70% on their heating and cooling bills.  For example, American Ingenuity can cool its 3,700 sq.ft. office domes to 76 degrees during work times for less than $133 a month in the hot Florida summer months.

 Ventilation Systems

The following came from their web site:  

http://energystar.gov/ia/new_homes/features/SupplyVent1-17-01.pdf 

The air within homes can become stale from moisture, odors, and pollutants that penetrate the home or are generated internally by human activity and out gassing from building materials and furnishings.  A constant supply of fresh, outdoor air can provide greater assurance of good indoor air quality and improved comfort. 

In most homes, ventilation is provided accidentally when air leaks through the building envelope.  Accidental ventilation is unreliable because it is dependent on a pressure difference between indoor and outdoor spaces caused by temperature or wind variations.  Too much fresh air often enters a house during cold weather, causing uncomfortable drafts and high heating bills.  Not enough fresh air may enter during mild weather which can lead to poor indoor air quality. 

Air leakage through the building envelope accounts for between 25 percent and 40 percent of the energy used for heating and cooling in a typical residence.  Many new homes are being air sealed to reduce this energy use.  Where tighter construction reduces air leakage and accidental ventilation, active ventilation systems may be needed to provide fresh air. 

Figure 1 shows how supply ventilation works in a small home.  Outdoor air enters through a single intake and is distributed through ducts to the living room and bedrooms.  Stale air is removed by leakage throughout the building and through exhaust fans located in the kitchen and bathrooms.  The supply air intake should be located away from sources of pollution, odor or dust—such as the ground, garages, driveways and plumbing or dryer vents.  Supply systems can be turned off when homes are not occupied. 

Fresh outdoor air is provided continuously regardless of weather conditions.  Indoor air quality is improved where fresh outdoor air, low in pollutants, mixes with indoor air, which has become stale from human activity.  Fresh air is provided to the living spaces within a house through properly sized and located vents without causing uncomfortable drafts.  Filters and dehumidifiers can be added to the system near the intake to further remove pollutants and provide humidity control needed in hot, humid climates.  Thus, they can be used safely with all types of heating and cooling equipment. 

Supply ventilation creates positive indoor pressure.  This is advantageous in moderate and hot climates because positive pressure avoids pulling hot, humid air into wall cavities where condensation problems can occur.  In cold climates, positive pressure can possibly lead to moisture problems if hot, moist air is forced into wall cavities where condensation is likely to occur.  In addition, supply ventilation systems avoid “back drafting” combustion gases from appliances and fireplaces into homes.  

Resources for this article: 

The Consumer Guide to Home Energy Savings (Wilson and Morrill), available from the American Council for an Energy Efficient Economy at 510-549-9914

Moisture Control in Homes fact sheet available from the Energy Efficiency and Renewable Energy Clearinghouse (EREC), POBox 3048, Merrifield, VA 22116, (1-800-363-3732)

EPA Energy Star

Exhaust Ventilation Systems

To read about the Ai dome and Heat Recovery Ventilators, click on HRV.  To read the most common asked energy questions with answers, click on Energy FAQ.  To read about the Ai dome and geothermal pipes, click on GeoThermal

The following came from the EPA’s Energy Star web site:

http://energystar.gov/ia/new_homes/features/ExhaustVentilation1-17-01.pdf 

The air within homes can become stale from moisture, odors, and pollutants that penetrate the home or are generated internally by human activity and out gassing from building materials and furnishings.  A constant supply of fresh, outdoor air can provide greater assurance of good indoor air quality and improved comfort. 

In most homes, ventilation is provided accidentally when air leaks through the building envelope.  Accidental ventilation is unreliable because it is dependent on a pressure difference between indoor and outdoor spaces caused by temperature or wind variations.  Too much fresh air often enters a house during cold weather, causing uncomfortable drafts and high heating bills.  Not enough fresh air may enter during mild weather which can lead to poor indoor air quality. 

Air leakage through the building envelope accounts for between 25 percent and 40 percent of the energy used for heating and cooling in a typical residence.  Many new homes are being air sealed to reduce this energy use.  Where tighter construction reduces air leakage and accidental ventilation, active ventilation systems may be needed to provide fresh air. 

Figure 1 shows how exhaust ventilation works in a small home.  Indoor air is continuously exhausted from a central fan (shown) or remote fans usually located in bathrooms.  Fresh outdoor air can be drawn into the house through remaining leaks in the building envelope.  Homes built with extremely tight envelopes may require the installation of room wall ventilation openings or specially designed windows that allow outdoor air to enter. 

These opening are sized and located to allow the proper amount of fresh air to enter homes without causing uncomfortable drafts and to prevent indoor pressurization.  Kitchens should have separate, manually operated, exhaust fans. 

The advantages of exhaust ventilation are control and consistency.  Moisture, odors and pollutants are removed continuously, regardless of weather conditions.  High indoor air quality is maintained due to the constant infiltration of outdoor air. 

Exhaust ventilation systems are most suitable for moderate climates.  Care must be taken during design and installation to prevent these systems from “back drafting” dangerous combustion gases from fireplaces and gas appliances into homes. 

Resources used for this article:

  1. The Consumer Guide to Home Energy Savings (Wilson and Morrill), Available from the American Council for an Energy Efficient Economy at 510-549-9914
  2. Moisture Control in Homes fact sheet available from the Energy Efficiency and Renewable Energy Clearinghouse (EREC), POBox 3048, Merrifield, VA 22116, (1-800-363-3732)