Re: Corn cooler...

Noon-Air <[EMAIL PROTECTED]> wrote:

>> ...32 F and 95-98% RH is good for storing sweet corn.
 
>exactly what I said

OK... :-)

>> >> ***Circular*** air patterns?
>> >
>> >Yes..it is very low velocity and helps maintain the required 90 - 95%
>> >humidity.
>>
>> Making the coil temp close to 32 F seems like a good idea. Or misting
>> the corn or the floor of the box when the RH falls. Who cares whether
>> the air flows in magical circular paths?
>
>ummmm....the coil is gonna be a lot colder than 32 degrees to achieve a 32
>degree box temp....or did you miss that page in the book??

That's a thought from ag engineer David M. Ross... 

http://www.agnr.umd.edu/users/Bioreng/portacooler2.htm
 
  The USDA Portacooler was designed to remove field heat from highly
  perishable fruit, vegetable, or cut flower product. It is not the best type
  of cooling unit for moderate or long term storage. This cooling system is
  a dehumidifier and... it will gradually dry out the product being cooled,
  if used for very long. For best cooling and long-term storage, select
  cooling equipment with an evaporator coil that operates just below the
  desired storage temperature so little moisture is condensed out of the air.

>> >> Open the door to reduce humidity?
>> >
>> >yup... think about it
>>
>> The humidity ratio of 32 F air at 98% RH is 0.00379, no? The same as
>> 70 F air at 24% RH. If we open the door when the room RH is higher
>> (quite likely), room air will condense more water inside the box.
>
>70 degrees @ 24% RH?? you live in a desert??

No. And most people don't, so the SRC criminal's idea to "open the door to
reduce humidity" won't work unless one lives in a desert, in very dry air
with a dewpoint below 32 F. With more humid air, opening the door will add
moisture to the cooler.

>> >> A concrete ("cement") slab is a good insulator?

The end of our phone conversation went something like this:

Criminal: "Whatever you do, don't put the cooler on a wood floor. Wood just
sucks the heat out of the cooler."

Me: "Do you believe that concrete is a better thermal insulator than wood?"

Criminal: "Yes."

But of course it isn't. Look it up. Concrete is about R0.2 per inch,
and wood is about R1 per inch, five times better as an insulator...

>> >...good enough for walk in coolers and freezers all over the world

Most may have been built in days of cheaper energy.

Nick