Will you change??

[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.

[agchat]

"The moisture carried in that hot air collides with the cold grain and is released into the grain."
I do think that alot of this study has a way to many factors involved. The quote from the article is something that is the key factor. Sure if you take grain at 18% moisture and lets say a temp of the grain being 20 celsuis. Now take grain harvested at 18% moisture, if it is a hot day, lets say 30 C, we all know that grain will at least be, if its sunny, 35-36C.
Then why would you not turn your fan on right away? Outside temp during sunny days are always cooler than grain temps till evening.

[Hopperbin]

That Palmer got some seriously flawed shit going on there, I don't care how many degrees he's got he wrong. What does he hope to do by telling us that crap? We all know you cannot dry at night when the humidity is up. Cooling the bin down with night air only is not going to speed up the drying or take more moisture out of the grain. He goes on to say that adding heat to the air will not help drying. I am sure Dry Air should be turning over in their graves with this news as they have studies that show the best way to dry grain is with heat. This guy goes on to say that they put 20 percent moisture grain in a bin and dried it with night air, no way in hell. I can see some moisture coming out of the grain as the grain temp drops but no way in hell will you will dry 18 percent moisture grain with night air, every grain farmer knows that.

[TOM4CWB]

This is a matter of cooling the grain.

If the night temp is 8C... cooling the grain at 25C... the air increases to 25C in the grain and bin...and has extemely low RH because the GRAIN heated up the air. Our Fans are on all day/24hrs once we start cooling grain. Once down to 10-12C... the moisture drops one point just on the 25C to 10C grain temp change... plus the storability on 10C grain is 10 times longer than at 30-35C as it will be at the top of the bin on a full bin/hot day.

[fjlip]

Tucker, that is what I always thought, "water carrying capacity".
Therefore cooler humid air removes zip from your grain, it has less capacity.

Maybe he is talking about DRY cold air, like all winter? Never tried that.