Positive static head & Condensate

[Manu68]

Dear Experts,

Is there any corelations available to calculate the static head developed in terms of Pascals for a given room when the supply and exhaust air flow rates are known. How to calculate the condensate that can be recovered over a year's period. The plan is to use the condensate as make-up water in the cooling tower.

Thanks in advance.

 

[trashcanman]

Difference in pressure will be very small = positive pressure from supply to return, in " water gage. 27.7 "w.g. = 1 psi. So, 1" w.g. = 0.036 psi. I doubt there is enough static head difference to do any good. Just use a condensate pump. Little Giant makes a peristaltic pump that would work just fine.
Now, as for using the condensate for makeup water, that is not worth the piping required. Condensate is the net difference between the grains moisture in incoming air and discharge air. 1 pound of water = 7000 grains. Typically, the condensate is a small trickle, unless you have a massive 100% outside air unit. Why bother? If water is so scarce (as in the Mid East), there won't be much (if any) condensate recovered anyway from the air. In Baghdad for instance, I never saw any storm drain systems. It does not rain enough to justify such investment.

 

[BronYrAur]

I'm confused on the question. If you are asking what trashcanman is answering, then I agree with him. Unless you are bringing in enormous amounts of OA, and conditioning it, you won't get much condensate out. Still confused what "stack head" means in this application.

 

[Manu68]

Hi BronYrAur,

I was verifying if there is a formula available that can calculate the positive pressure in a conditioned room if the treated fresh air quantity and exhaust air quantity are known. Thanks.

 

[BronYrAur]

that is entirely a function of how tight the room is. Every crack must be known so that you can determine the air leakage. ASHRAE has some formulas on it, but you must know the cracks you have