How to calculate hydrogen ventilation requirements for battery rooms.

For standby DC power systems or AC UPS systems, battery room ventilation is calculated in accordance to EN 50272-2 Standard.

Battery room ventilation flow rate is calculated using the following formula:

Q = v * q * s * n * I gas * Cn / 100

Q = ventilation air flow (CMH)
v = necessary hydrogen dilution factor (depends on % of air-hydrogen mixture)
q = hydrogen release rate, typically=0.00042 m3/Ah
s = safety factor, generally=5 for building projects
n = number of cells
Igas = current producing gas during charging (A/100Ah)
Cn = rated capacity of battery (Ah)

Igas values for stationary lead-acid batteries are (according to EN 50272-2: Stationary Batteries):

Vented lead-acid cell on float charge: 0.005 A/Ah

Vented lead-acid cell on boost charge: 0.02 A/Ah

Valve-regulated lead-acid (VRLA) cell on float charge: 0.001 A/Ah

VRLA cell on boost charge: 0.008 A/Ah

The Ethos Power free hydrogen venting calculator calculates hydrogen vented from a range of types of batteries; valve regulated lead-acid (VRLA), vented lead-acid (VLA), and wet-cell NiCd (NiCd). Furthermore, for each type of battery, the charging modes of float or boost charging can be selected, as can the allowable concentration of hydrogen and other factors. We hope you find this calculator useful and that you contact us for assistance, perhaps with designing your battery room, or obtaining quotes for high quality industrial batteries of any type.

free hydrogen venting calculator

Current rating: 2.7


Stan Grace 2 years, 8 months ago


Your free hydrogen venting calculator helped me enormously also.

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Drape Divaa saree bags 4 months, 3 weeks ago

What's up, yeah this post is truly fastidious
and I have learned lot of things from it regarding blogging.


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Vanya Smythe 2 years, 6 months ago

Thanks Stan.

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Hal 1 month, 3 weeks ago

Hydrogen venting calculator- what type of number are you looking for with the volume of batteries in battery room? Percentage? Sq meter? Nothing seems to work

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