Heating and Air Conditioning

an American Ingenuity Dome

A.I. does not specify which heating and cooling units to use within its domes because the needs vary by regions of the country. Heating and cooling systems that are practical or common in your area can be used in the dome. We have had clients use radiant heat in the floor. We have also had clients’ incorporate large spans of glass to let in the passive heat; usually this is not practical, as the dome is so energy efficient. The large amount of glass just lets in hot or cold air. Our clients have had great success with solar hot water heaters.

For a system that is best for your area, consult a local air-conditioning contractor. All types of systems will work but it would be important to consider what type of fuel is readily available, what type of units can be serviced locally and your own preferences. However, keep in mind that because of the superb energy efficiency of the dome, you can reduce the required size of your air-conditioning and heating system by about one third. Also the cost of heating and air conditioning will also be about half that of typical houses in your area and therefore the savings provided by super efficient units will be less. It is economical to select efficient systems but not very expensive systems.

Can the smaller American Ingenuity domes be cooled or heated without central air conditioning or furnaces? Yes. The smaller sized American Ingenuity domes have such small heating and air-conditioning demands; it could be practical for you to use only a window air-conditioner and a space heater. A ventilating wood stove or fireplace may provide all the needed heat for even our larger domes located in cold climates.

What air conditioner size do you recommend for your domes?

34’ Dome: 1 ½ Ton

40’ Dome: 2 Ton

45’ Dome: 2 ½ Ton

48’ Dome: 3 Ton

60’ Dome: 4 Ton

Tell me about a ground water heat pump. A ground water (or water-to-air) heat pump is extremely efficient as it uses the constant moderate temperature of underground water to both heat and cool, instead of using outside air, it uses water from a well or underground loop to transfer heat through a concentric copper coil located inside your home. Besides being more efficient than air-to-air unit, it can produce heat when the outside temperature is below freezing.

Can A.I.’s Domes be cooled without an air conditioner? Yes. Because the A.I. dome is so super insulated, our clients who do not prefer air conditioning, have found the interior of the dome to be cooler than a conventional house.

• Of course you would want to install windows and doors opposite of each other so that air will flow through the dome.
• Install ceiling fans to move the air.
• Install awnings out from the dormers and entryways to keep the sun from beaming into the dome.
• To help maintain a cooler interior temperature you may want to consider installing underground cooling pipes which will bring air into the dome that has been cooled by the earth. To learn more about this read about Energy Efficiency under advantages.
• Plus you can install pipes in the slab to run cold water through. A 45’ dome needs about 2 ½” in diameter cooling pipes that are buried 5’ deep and go out about 20’. You angle the tubes where condensation can be pumped out.
• Also use tankless water heaters (or on demand water heaters) to cut down on the heat generated by a conventional water heater.
  

Does the HVAC diagram come with the Building Plans? No. The installation and routing of the heating and cooling ducts, electrical wiring and plumbing pipes can best be determined on site by the person making the installation. A.I. has found if the layouts are included, then the inspectors require the subcontractors to follow the diagrams when usually the subs like to do their own layouts.

Where are the AC and Heating Ducts installed? The ducts can be run in the interior walls, second floor joists, and behind the second floor perimeter knee wall.

What types of Ducts does your company recommend? Collapsible plastic inner and outer liners have insulating material between the inner and outer liners and a spiral wire that holds them round. Because the dome is all one cooled or heated space (no attic), the ducting does not need to be insulated. Sometimes though building departments require insulated ducts.

Where are the AC and Heating Vents installed? The vents are installed in the interior walls or are installed in the floor of the second floor.

How do you move hot air from the second floor to the first floor? In a vertical wall near the top of the dome install a bathroom exhaust fan that can be turned on to move hot air to the first floor. Use dryer ducting for the exhaust fan ducting. It extends down the interior wall, through the floor joist and vents out on the first floor. Plus you can install ceiling fans and set them to push the hot air downward.

How can I calculate the BTU requirements for A.I. Domes? You can calculate the approximate amount of heat required for the different size A.I. domes by:

• Determine the difference in temperature from outside to inside. Say inside is 70 outside is -30, T= 100
• Look up the Exterior surface of the dome you want to calculate (on back side of Price list) 40’ dome =2,645
• On the bottom of same Specifications sheet get the K value for the insulation. 9" K=0.0278
• Multiply all of these numbers together. 100 x 2,645 x 0.0278 = 7,351 is the BTU's required to make up what escapes through the dome surface.
• Do the same thing with the windows. T= same, Add up the areas. For a double pane use K=0.3 or what ever the mfg. specifies.
• Do the same thing with the floor and its insulation.
• Add the three BTU values together and that is the approx. heat loss.
  

Does American Ingenuity’s building plans meet the new building codes requiring air exchangers? We are not sure what your code requires, if there is a minimal air exchange from the outside to inside, that requirement would best be fulfilled with an air to air heat exchanger sometimes called a heat recovery unit. These ventilation systems bring in fresh air and minimize the loss of heating and air conditioning.

Tell me about humidity control within the A.I. Dome: Usually there only needs to be windows for second floor cross ventilation or an exhaust vent installed in the top of the dome to remove the moisture. Plus, the running of the AC or furnace will dry the air when they are in operation.

One of American Ingenuity's Missouri Dome Owners, Todd Nicks, sent us the following email in reference to humidity control. "I was having trouble with winter humidity in my dome until this February 2006 when I purchased and installed a Heat Recovery Ventilator (HRV). Air quality is noticeable fresher and relative humidity is under control. The HRV has eliminated the need to run dehumidifiers during the winter for me. Additionally, small dehumidifiers are electricity hogs (costing more to operate than central air in the summer).

My home does have high cfm fans in all bathrooms and kitchen vent fans as well. I tied my bathroom vents to the HRV which has a humidistat that kicks it into high gear when the bath humidity hits it.

My dome is still a work in progress, but I love being the first and only one around here to "think outside the rectangle" in home design. The spaces in a dome have amazing character....anyway just wanted to share an idea that has helped me defeat the humidity monster in my dome."

We asked him where and how did he install is Heat Recovery Ventilator?

He replied, "I installed the HRV in my utility room with an insulated intake duct through a joist space. The unit I installed was manufactured by Lifebreath (model 200 max). Depending on which standard is used it may be slightly undersized, but works fine. Three of my bathroom vent fans had previously come together in the utility room to exit through a single 6" vent (I had a box with dampers to prevent backflow). I connected the HRV to those three bath vents which allowed me to pull air from three different floors of my dome.

The HRV I installed has a humidistat in its exhaust air stream (household intake). When someone is taking a shower that humidity causes the HRV humidistat to switch the fan to high speed. I have mine set on low speed continuous as a default."

The following information came from Life Breath's web site: http://www.lifebreath.com/life.htm A way to minimize energy use and at the same time fill your home with fresh, healthy air is with Lifebreath Heat Recovery Ventilation.

On American Ingenuity’s web site, See the Advantage, Energy Efficiency for geo thermal systems, radiant floor heating systems, solar hot water panels, photovoltaics, wind turbines, etc.