Dome Mechanics

The basic elements necessary for total dome comfort are:

• Heating
• Cooling
• Filtering
• Humidifying
• Dehumidifying
• Whole House Ventilation

All of the above are necessary, for the most part, and Dome Mechanics embraces the systems that make the dome environmentally comfortable, as well as economical.

A Whole House Ventilation System Recently, one of our customers decided that they wanted a whole house ventilation system and conveyed their desires to their architect. His answer was to install a fan in the dome top inside a cupola. This would most certainly work well to accomplish the desired effect. But upon looking at the options, that type of system would have some negative effects. The installation of a fan in the dome top would require an opening to be cut in the dome’s surface. This would cause a possible place for heat to leak to the outside.

It would also require that another piece of mechanical equipment would need to be installed in a comparatively inaccessible place. This fan is totally unnecessary and can be replaced by a system that costs less to install, and completely eliminates the possibility of losing heating units out through the opening in the dome top. To accomplish whole house ventilation, it is only necessary to install a butterfly valve at the furnace discharge that can direct the air flow from the furnace, either to the outside, through the foundation, or back into the house for heating and cooling.

Dome Top Air Circulation

Recently we noted that some dome manufacturers are touting the dome top air circulation, where the return air in the heating mode takes converted air that has found its way to the dome top and returns it to the lower regions—where you live. This is an excellent idea that conforms to standard physics principles, that hot air rises and the system is picking it up at the dome top where the excess BTUs can be saved and used again. However, some dome companies are suggesting that the furnace fan be reversed in the cooling mode, and deliver the cooled air to the dome top, where it can fall to the lower levels.

Basic Physics

Once again, this flies in the face of basic physics. Reversing the fan causes the following: by introducing the cooled air at the lower level (the same as you do with the heated air) you accomplish two advantages over introducing cooled air at the dome top. When the cooled air is introduced at the dome top, it is at its maximum cooled temperature. It immediately starts to warm as it falls to the lower regions of the dome where you live, and some of the cooling BTUs are lost in the process. Those BTUs are critical, as tests that we have conducted indicate that the air conditioner can be set several degrees warmer than if the cooled air is introduced at the top. The reason is the same as in the heating mode. Several degrees of cooling load are lost as the cooled air is being pulled down from the dome top, and there is no reason to resort to the reversing of the circulating fan. These observations have occurred over the past 23 years. There is room for argument in all things. If the reader has additional information on this subject, I would be pleased to hear it.