AREA CLASSIFICATION - Hydrogen Ventilation
AREA CLASSIFICATION - Hydrogen Ventilation
(OP)
Project provides an installation of a small building where HYDROCARBON ANALYZER has to be installed.
Hydrogen has to be used as "fuel" for the HYDROCARBON ANALYZER providing an ionization of the gas samples.
Small vent-chimney is installed on the top of the building.
MY QUESTION :
(1) During summer-time when ouside temperature is higher then inside some problems with Hydrogen Ventilation can be expected.
IS THERE ANY CHANCE THAT HYDROGEN AS LIGHT GAS CAN BE CONCENTRATED INSIDE A BUILDING BECAUSE OF WARM AIR OUTSIDE OF THE BUILDING. CAN THAT WORM AIR ( heavier than hydrogen)
CLOSE THAT CHIMNEY MINIMIZING A NATURAL VENTILATION OF THE HYDROGEN.
Hydrogen has to be used as "fuel" for the HYDROCARBON ANALYZER providing an ionization of the gas samples.
Small vent-chimney is installed on the top of the building.
MY QUESTION :
(1) During summer-time when ouside temperature is higher then inside some problems with Hydrogen Ventilation can be expected.
IS THERE ANY CHANCE THAT HYDROGEN AS LIGHT GAS CAN BE CONCENTRATED INSIDE A BUILDING BECAUSE OF WARM AIR OUTSIDE OF THE BUILDING. CAN THAT WORM AIR ( heavier than hydrogen)
CLOSE THAT CHIMNEY MINIMIZING A NATURAL VENTILATION OF THE HYDROGEN.





RE: AREA CLASSIFICATION - Hydrogen Ventilation
An inverse draft situation could indeed be originated by a density reversal. A small fan could be used to ensure that the generated gases are always expelled from the analyzer housing through the chimney.
RE: AREA CLASSIFICATION - Hydrogen Ventilation
The density difference between H2 ( mw=2 ) vs air ( MW=29) would imply the outside air would need to be about 14.5 times greater than the hydrogen to cause a reverse draft. Indoor air at 60 F ( 520 R) and outside air at 7540 R is a mighty warm day.
RE: AREA CLASSIFICATION - Hydrogen Ventilation
Hope this helps.
saxon
RE: AREA CLASSIFICATION - Hydrogen Ventilation
Also, analyzer buildings are generally air conditioned.
My electrical friends also say that the analyzer room is classified as non-hazardous by the NEC. For additional information on area classifications see API 500.