any correlation btwn cfm and gal/day - evap. humidifiers?

[bearsfeat]

Hello,

Thanks for you interest in my question. Restated in more detail, the question is:

With respect to evaporative humidifiers, I would guess that there is some correlation between CFM and rate of output, or gallons of water per day. Of course, this would only be true for a given system with all other things being equal, i.e. wick efficiency, R.H., ambient temp...etc. Is this true to any extent, and are there any rules of thumb defining this relationship? What are the system variables that drive such a relationship?

Thank you for any input or ideas.

Nathan Rollins
BearsFeat Consulting Services
bearsfeat.com

 

[quark]

There is no simple solution for this. That mainly depends upon the wet bulb temperature and evaporation efficiency. For estimation, a ball park figure of 75% is good enough. As the process is isenthalpic, you can do energy balance to derive a relationship if you know some parameters.

1.08 x cfm x (T1-T2) = 1000 x m

Where T1 is initial temp. of air in deg.F
T2 is final temp. of air in deg.F
m is mass flow rate of evaporating water in lb/h.
1000 is latent heat of water in btu/lb

I ignored mass addition to air flow in terms of water vapor as this quantity will be marginal when compared to mass flow rate of air.

Regards,


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