Let's consider the home first. Experience shows
that "well insulated," conventional homes in the northern United States take approximately ten watts of heat per
square foot. So, a 1200-square-foot, well insulated, conventional home takes about 12,000 watts of heat. But a Monolithic
Dome with that square footage can be heated with approximately 2 watts of heat per square foot. But heating systems are not
designed for that small of an output. Therefore, we recommend using small electric heaters scattered throughout the house,
or better yet, a circulating hot water heat system in the floor. Typically, we use 1/4-inch tubes every two feet in the floor
and a conventional 40 or 50 gallon water heater to heat the water. Obviously, the other rules of layout utilizing manifolds
and pumps are needed. The heating system does not have to be very significant, but the floor under it should be insulated.
Cooling in the south half of the U.S. can easily be accomplished with one ton of air conditioning per 1000 square feet
of home. Air-conditioning systems usually start at a minimum of 1.5 tons, so a Monolithic Dome up to 1500 square feet requires
a single 1.5 ton unit. It's sometimes argued that such a structure requires more than 1.5 tons because it's cheaper.
In reality we need to use the 1.5-ton unit because it will run more and control humidity better. So the rule of thumb is 1
ton per 1000 square feet. Obviously, someone with a cooking kitchen for the harvest crew may need more, but for a normal home
the one ton per 1000 square feet works very well and requires only the purchase of a 1.5-ton unit -- the smallest and least
expensive that's commercially made.
Maranatha Christian Church in Mont Belvieu, Texas
has 70 tons of air-conditioning for a 40,000 square foot sanctuary. They also have more capacity than they need. This is also
verified by their $1200 to $1500 per month power bill for hot, summer months. In general, it is far better to operate the
cooling system more hours, both before and after a meeting, than it is to have a huge system that turns on for just half of
the meeting, as it does in churches with excessive cooling systems. At Abundant Life, theirs goes on and off all through meetings
-- on for a few minutes then off for quite a while. It's more efficient to run a smaller unit continuously.
it's extremely difficult for HVAC engineers because there is little history on cooling Monolithic Domes. So, their "necks"
are on the line. They are extremely worried about under-designing and upsetting the client. On the other hand, when they over-design
they cost the client enormous amounts of money for initial installation, as well as ongoing energy and maintenance. With these
oversized systems, the demand charge (charge incurred by simply turning the equipment on and creating the demand) can be larger
than the actual operation charge. Experience has to be the teacher. Experience on these large, occupied Monolithic Domes shows
that one ton of cooling per 1000 square feet of space is a good rule of thumb.