Will you change??

[cottonpicken]

My brother has a masters of engineering degree in
fluid dynamics,i'll get him to explain why or if its true.

[freewheat]

I am not very sure about this at all.
Where did they do this test, Indian
head? Which is not really dry nor wet
area, I suppose... hmmmmm... The idea
that on a warm moist night, that the air
holds little moisture is bizarre. I
would say half the nights here are
foggy. I fail to see how running fans in
fog when the "air can hold less moisture
due to it being cool" could be helpful.

Or maybe I am a throwback.

Most guys aerate to maintain condition
anyway, drying is a bonus.

I think I will stick with warm dry days,
and leave the wet sticky nights to the
owls!

[cottonpicken]

Actually.... if you reverse engineer this bitch we could
start adding moisture to grain to make more money
in the elevator instead of selling them super dry stuff
all the time.

[furrowtickler]

thinkin the same cotton - 10% wht and 6% canola is lost money...

[fjlip]

"For example, at 27 C the air can hold 4.3 kilograms of water; at 50 percent relative humidity it is holding 2.15 kg of water."
Very confusing info. What is RH at 27C? What is temp at 50% RH?

"But cold air has less capacity to hold water. So a higher relative humidity, say on a cool night, actually can mean less water in the air than during the hot day."
The issue is the moisture in the grain, hot air holds more moisture therefore removes it from wet grain.

"The moisture carried in that hot air collides with the cold grain and is released into the grain."

Grain usually warm in the fall, almost sounds like the fan is running in May when grain is near zero.

"Even on a hot, humid summer night, the amount of water in the air is actually small, Palmer said."

We have cool humid nights, a hot night is rare. The RH usually 90% plus.

[agchat]

Now to add my two cents, after all I did start this thread, I always monitor the humidity, no matter if we are cooling or drying. If th RH is over 85% by 11 or midnight, the fans get turned off. I just do not seeing especially over 90 RH being sucked into a bin for more than 8 or 9 hours. Maybe I am totally wrong.

[bluefargo]

The gentleman was interviewed on CBC Radio at noon today. I listened very intently. You bet I'll change the way I do things. We have been guessing all these years. Finally someone actually did some research, It is counter intuative but made good sense. Ignore these results at you peril!

[Tucker]

I think the gist of the article is the idea that cool night air with high RH still
carries less water into your grain than hot daytime air with lower RH. Plugging
average Regina mid-September values for temp and humidity into a psychrometric
calculator seems to support this theory.

Daytime air at 20 degrees C and 40% RH will hold 5.898Kg of water per 1000Kg dry
air. Night time air at 6 degrees C and 85% RH holds a little less at 5.004Kg per
1000Kg dry air.

I think that this just shows that night time humidity isn't that bad so it's okay
to run your fans 24 hours. That being said however, 30 degrees C and 50% RH air
holds 13.551Kg of water per 1000 Kg dry air. You might want to stop the fans
during a hot, humid day.

[fjlip]

And a dryer works how? 25C and 30%RH air heated to 180F sure works.
Try it without the heat.
I always thought raising temp lowers RH.

In the interview did he explain the hot air cold grain statement?

[Tucker]

Using your example of 25 degree air at 30%
RH heated to 82 degrees C, that air will
now have a RH of only 1.85%. The water
content of your air didn't change but the
extra heat added a huge amount of water
carrying capacity to it. It's now
(relatively) dry as a popcorn fart and
capable of carrying tons of water out of
your grain as it's pushed through.