I need to keep an 8x40' steel connex cool that is filled with electrical components. We call this unit the Drive house. When the unit is running at 100% capacity, we're drawing 2.1 megawatts of power and it all flows through the drive house and then to the other units. There are multiple computers, PLC's, 12 heavy duty VFD's and 42 AC drive units all generating heat. Our process generates a lot of fine dust so we have to keep the drive house closed up. (sorry for vagueness, there's an NDA)
Since this is a prototype unit, we are learning some things the hard way. No one considered heat build up in the drive house. On a heavy overcast 55° day the temp inside the drive house was hitting 110°. We installed the biggest residential portable AC unit available for purchase in Alaska which was 10,000BTU. On the same 55° overcast day with the portable AC, the drive temp stayed around 75°. Then the sun came out. On a full sunny day at 70° OAT the drive house temp exceeded the range of our thermometer which tops out at 120°. The VFD cabinet got hot enough to cause several VFD's to shutdown with overheat faults. I think the VFD high temp shutdown is 160°
We were fortunate that the unit's first job was in a coastal town that gets 70" of rain and 365" of snow annually, so we rarely saw sunny skies.
Our innovation team (the group with all the engineers) has tasked me (the unit operator who knows nothing about sizing HVAC) to find a cooling solution before our next job. Our next job will be in a region that sees a lot of sunny days and much higher OAT's (80-100°).
I did the guy thing and googled "portable industrial cooling", clicked on the largest unit in the listing which was 7.5 tons. The unit will fit in the drive house and 480v 3ph is available. A bargain at $9800.
Thought I was done, then a buddy says, "hey, its not good to have too big of a unit either" Great!
So, how does a fellow who sucks at math and doesn't know the wattage of 99% of the heat generating gadgets figure out the proper size A/C unit to buy? If you, (the professionals) got a call from a customer (the idiot) describing the above scenario, would you be able to guesstimate the tonnage needed?
I've also reached out to a couple industrial cooling rental outfits but waiting to hear back.
Thanks.
Since this is a prototype unit, we are learning some things the hard way. No one considered heat build up in the drive house. On a heavy overcast 55° day the temp inside the drive house was hitting 110°. We installed the biggest residential portable AC unit available for purchase in Alaska which was 10,000BTU. On the same 55° overcast day with the portable AC, the drive temp stayed around 75°. Then the sun came out. On a full sunny day at 70° OAT the drive house temp exceeded the range of our thermometer which tops out at 120°. The VFD cabinet got hot enough to cause several VFD's to shutdown with overheat faults. I think the VFD high temp shutdown is 160°
We were fortunate that the unit's first job was in a coastal town that gets 70" of rain and 365" of snow annually, so we rarely saw sunny skies.
Our innovation team (the group with all the engineers) has tasked me (the unit operator who knows nothing about sizing HVAC) to find a cooling solution before our next job. Our next job will be in a region that sees a lot of sunny days and much higher OAT's (80-100°).
I did the guy thing and googled "portable industrial cooling", clicked on the largest unit in the listing which was 7.5 tons. The unit will fit in the drive house and 480v 3ph is available. A bargain at $9800.
Thought I was done, then a buddy says, "hey, its not good to have too big of a unit either" Great!
So, how does a fellow who sucks at math and doesn't know the wattage of 99% of the heat generating gadgets figure out the proper size A/C unit to buy? If you, (the professionals) got a call from a customer (the idiot) describing the above scenario, would you be able to guesstimate the tonnage needed?
I've also reached out to a couple industrial cooling rental outfits but waiting to hear back.
Thanks.
source https://hvac-talk.com/vbb/threads/2243742-Advice-on-cooling-a-very-hot-8x40-connex-filled-with-computery-stuff?goto=newpost
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