DOME MAGAZINE: Winter 1998-99, Vol. 11 | No. 2
Recently I visited a dome that was built about 1991. This dome has a top pentagon of plastic skylights. The owner stated that he had problems with the skylights collecting moisture. He had talked to the manufacturer who informed him that they had a solution to that problem, though they had not divulged just what it was.
It’s difficult to understand the fact that a simple solution is available to stop condensation during cold weather. Since glass or plastic skylight windows have a relatively low R value compared to the rest of the wall system, the glass surface is bound to be cooler than the surrounding wall.
Since it is cooler than the surrounding wall and the air, moisture that is in the normal humidity of the house will collect on its surface. This is exactly what happens to the windshield of an automobile when the car is in the heating mode and the outside air is colder. And what is the solution?
A Solution for Skylight Moisture
Turn on the heating fan and BLOW it off. So if you are preparing to install skylights in your dome top, make sure there is air passage over the glass to eliminate condensation drip. This is our solution to skylights or other window types that may want to collect moisture. Of course, if you had really dry air, this is not needed, but living in a house with no humidity is impossible.
This solution may not be required in temperate climates, but if air-conditioning is needed, the same kind of treatment is necessary. We have lived in houses that were heated with hot water or steam-heated radiators. The results were that we had to provide a humidifier 24 hours a day in order to make the environment livable.
This is one of the reasons that we strongly recommend the use of a forced air system. We are not shilling for any particular make of forced air heating systems.
Air Movement
Air movement within the dome is essential for total comfort. We recommend the return air inlet be installed near the dome top to retrieve the heated air that rises through convection currents and returns it to the lower levels where you live. This eliminates the problem of the second floor rooms, which most domes have, of becoming too warm.
Radiant Heating
The radiant-floor-heating salesman is out there selling the concept, but the fact remains, when that type of system is installed in a dome home, it only satisfies one phase of the requirements that are necessary for total dome comfort.
Since radiant floor heat, or any other type of radiant heater, only satisfies one phase of the need for comfort—that of heat. What other conditions occur that need treatment to insure total dome comfort?
The need for cooling and subsequent dehumidifying is necessary in some areas. This is normally accomplished with a room or central air-conditioner, which can become a part of the forced air system. The third condition necessary for creature comfort is the filtering of the air within the home. For total comfort, and a matter of health, dust particles should be removed.
All of the above should be code requirements, and can be accomplished with a forced air system, but sadly, they are not.
Forced Air System
The number one benefit of the forced air system is being able to keep the air moving, equalizing the temperature in the home, as well as eliminating any possibility of internal condensation problems.
I have heard the complaint that the forced air system is too noisy. The reason is one of economics. When the system was designed, the smallest ducts that they could use, and get away with, were recommended and installed. The smaller the duct, the less the cost, but the more noise that is created as the air is forced through.
A well-designed forced air system with large enough ducts will make the movement of air exceedingly quiet. The purpose of this visit was to install glass windows to replace some panels.
This dome is of two by six construction with six inches of fiberglass insulation. When the panel was removed it was discovered that some of the insulation was wet. The dome is a hub and strut system, but no provision was provided to eliminate the cavity moisture that inevitably occurs in dome panels when they are constructed in colder climates.
These studies have been made by many dome companies who design and build in the climates where the temperatures move from -20o F to over 100o F.
The above recommended systems were designed to eliminate some of the objections that tend to keep the dome from becoming the housing of choice.
