3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
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Onan is not completely correct. At least, they way they state it leaves out some important information.
While it is true that there is a reduction in oxygen, it is not because there is any less oxygen available in the atmosphere. Actually, it is because there is less atmospheric pressure.
At sea level, we use a reading of 30 inches of mercury (30 in Hg) as a "noninal" atmospheric pressure (round numbers, gentlemen). As we increase elevation each 1,000 feet we see a reduction in atmospheric pressure by 1 in Hg. Thus, at 5,000 feet, pressure would be 25" Hg.
Since the ratings for internal combustion engines are "standardized" at sea level, any increase in altitude causes a drop in pressure to force air/fuel into the engine and a drop in absolute manifold pressure for the engine. I guess that is where Onan comes up with the explaination of less oxygen.
Conversley, if we go below sea level or barometric pressure should rise due to a weather front, the available power of an internal combustion engine would rise with the atmospheric pressure. I guess we could call this "nature's supercharger?"
Elevation also has a major impact on the temperature water boils and baking cookies :).
bobandcat wrote:
Altitude is by far the larger factor in output loss. This is due to the reduction of available oxygen used in combustion. The temperature also reduces the density of the air and to a lesser extent than altitude, also reduces the available oxygen. By the way, Onan is my source of the info regarding power reduction for altitude and temperature.
Onan is not completely correct. At least, they way they state it leaves out some important information.
While it is true that there is a reduction in oxygen, it is not because there is any less oxygen available in the atmosphere. Actually, it is because there is less atmospheric pressure.
At sea level, we use a reading of 30 inches of mercury (30 in Hg) as a "noninal" atmospheric pressure (round numbers, gentlemen). As we increase elevation each 1,000 feet we see a reduction in atmospheric pressure by 1 in Hg. Thus, at 5,000 feet, pressure would be 25" Hg.
Since the ratings for internal combustion engines are "standardized" at sea level, any increase in altitude causes a drop in pressure to force air/fuel into the engine and a drop in absolute manifold pressure for the engine. I guess that is where Onan comes up with the explaination of less oxygen.
Conversley, if we go below sea level or barometric pressure should rise due to a weather front, the available power of an internal combustion engine would rise with the atmospheric pressure. I guess we could call this "nature's supercharger?"
Elevation also has a major impact on the temperature water boils and baking cookies :).
