Compressor Room Heat Relief 1

[Drazen]

Who knows the best approach to compressor room heat exhausting problem. Installed power is ca. 650 kW so any kind of cooling seems very cost ineffective as maximum allowed room temperature is 35 Deg. C, and max. outside temperature is the same! I am considering different ventilation options, but fans appear extremely large and natural ventilation is questionable for room 16 x 7 m of floor area.

 

[KenRad]

What is your 35C temperature limitation based on? Intake air for the compressor? Ambient temperature for air compressors or air dryers? Is all the equipment in this room water cooled?

 

[russmech]

I wrestle with this problem every now and then. Calculating cooling air flows when the temperature differernce (between outside and inside design temps) is small seems to imply very large quantities of air are required. However, at some point, the ventilation air is not "cooling" the heat load, but "removing" it; that is, the room itself starts acting like an exhaust hood. An exhaust hood over a hot machine is a good analogy. I use a rule of thumb of 15-20 room air changes per hour as a base line. Of course more is better. Essentially, because you are replacing the air in the room so quickly, the outside air temperature simply becomes the inside air temperature (which in your case still meets mfr's recommendations). By intellegent placement of air flows, the ventilation air will "sweep" the heated air away from your piece of equipment and out of the room; and who cares how warm that air flow is if it's just heading out of the room anyway. I hope this helps. As a humorous point aside, I once had a code inspector apply a standard air flow equation with a small delta T (in just such a case as this) and try to tell me that I needed one million CFM to cool a small chiller room. It took all the restraint I had to reply to his comment without making him feel like an idiot.

 

[ChasBean1]

russmech, excellent post.