Filed under: Cooling, Geothermal Systems, Geothermal household energy, Ground Source, Thermal Footprint, geothermal energy exchanger | Tags: Add new tag, Air Circulation, air conditioning, Air Distribution Ductwork, comfort controls, Cooling, Ductwork, Geothermal Base Load, heating, Humidity, Return air for geothermal
I could add to the Return air for geothermal systems by adding that in a vaulted ceiling, or second story, it is best to have what is called a high return air intake for two story homes with only one air conditioning system. The high return air will capture, and return for conditioning, warmer air trapped in the upper levels of the structure. This allows the centralized thermostat control to more effectively control the overall temperature of the entire structure.
See ya,
Addendum:
There have been a lot of questions about Return Air. The amount of return air in terms of cubic feet per minute (CFM), or dimentionally (length x width, or diameter), of the return air duct, is generally determined by the amount of static air pressure designed into the air handler fan by the manufacturer. Most furnaces used to be designed around one inch water column air pressure, or more, delivering air at around 1000 feet per minute (FPM). The return air is usually designed around .01 to .05 inches water column, more or less. In order to Reduce the amount of design static air pressure the duct has to be made larger. Smaller ducts have more static pressure losses than larger ducts. The static air pressure is related to the velocity, (FPM), and the volume (CFM). Increase the static pressure cause a smaller duct with higher velocities, which can cause air noises in the ductwork. A return air cannot be too large because the air handler (furnace) cannot deliver anymore air than it takes in, and it cannot take in more air than it delivers. Its called a balanced system. I talked about negative, and positive air pressures in a structure, here before. There are high pressure systems that do not follow the above design characteristics.
Don’t forget the air filter. It causes static pressure losses also. To much filter, or a dirty filter can cause the refrigeration system suction pressures to drop below freezing. That can cause the condensate contain in the cooling coil area to freeze, and, enough ice can cause even more restriction to the air flowing over the cooling coil, which cause a loss in capacity, causing the house to get very hot, and humid. This condition is called a “Snow Ball”.
Change, or clean those filters!
See ya,
