Industrial dehumidifier

[firefighter ontheside]

Does anyone know anything about industrial dehumidifiers.  I'm gonna buy one for my wife's office because she got 3" of water down there this week and I need to dry it out.  I'm wondering if anyone has used one in a drying kiln.  After it's done at the office I'm thinking it will be good for my kiln, but not sure.  The one in question is a Drizair LGR 2000.  I'm buying it used.  It's descrived as low grain.  I don't know what that means.  Thanks in advance.


 

[Don P]

The weight of water in the air is measured in grains. I assume they are trying to say it gets you down to low moisture.
What the coils are made of is going to be the biggest thing, the moisture in wood is acidic, especially so with some woods like oak. Aluminum coils aren't going to last terribly long in that environment. Nyle offers several different coils at different price points. Ebac makes DH kilns and industrial DH units, the guts are basically the same, the controls are different but it isn't rocket science.

[Don P]

I stand corrected :. There is another stage before the cooling coils to get the incoming air closer to dew point so that the cooling coils work more efficiently. I read a few company blurbs this one was the best so far;
http://www.prodrying.com/lgr-dehumidifiers-a-8.html

[doc henderson]

5 grains of asprin is 325 mg.

[barbender]

Do you think your wiwife would notice the difference if you set a Nyle DH unit up in the office for a few days?😁

[firefighter ontheside]

Thanks for the replies.  Good responses.  I will only be putting air dried wood in the kiln, so I don't feel like the acidic oak is gonna be a big problem at that point.

The thought of a nyle in the office hadn't occurred to me.  The problem is that I already told her I found a dehumidifier for $800.  I'm not sure I can swing the $3000 for the nyle.  She's pretty smart.

[Don P]

5 grains of asprin is 325 mg.

The troy system historically was used for measuring the weight of drugs, precious metals and gemstones. The name comes from the French city of Troyes. The noble metals (gold, silver and platinum) all use the troy system. A troy ounce is 20 pennyweights. The pennyweight was the weight of a silver penny in medieval England. When pennies were introduced in England in the 8th century, their original weight is believed to have been 24 grains. This was gradually reduced, in at least thirteen stages until it reached 7.27 grains by 1816. 24 grains = 1 pennyweight and 20 pennyweights = 1 ounce troy.
Even more trivia if you'd like to read on. "Grain is an ancient unit which was originally based on the weight of a grain of wheat. The grain is the smallest unit of weight in the avoirdupois, troy, and apothecaries systems. Surprisingly it is identical in all three systems." 4 grains = 1 carat; 24 grains =1 pennyweight; 480 grains = 1 troy ounce; 15.432 grains = 1 gram.
"Although we have stated above that the grain weighed the same in all three of the above systems, there were at least two different grains. The troy system used the supposed weight of the barley grain, whereas the wheat grain was also used as a standard of weight. There were three barley grains to four wheat grains."

Drinking coffee and noodling around before going to CSM some butternut logs at the farmers market this morning. Ammunition also uses the same grain, 1/7,000 of a pound or .065 grams per grain

[K-Guy]

@firefighter ontheside 

The problem with regular dehumidifiers is two things.

1) Corrosion from the tannic acid. You are correct it will be less with air dried wood but it will still be there and cleaning it from the coils will be difficult if not impossible.

2) They only operate at low temperatures and that means very long drying times.

I hope this helps.

[firefighter ontheside]

Well, I bought the unit.  It's huge.  I've got it running at the office.  Hopefully it does a good job there.  That's my main concern.

[firefighter ontheside]

@firefighter ontheside

The problem with regular dehumidifiers is two things.

1) Corrosion from the tannic acid. You are correct it will be less with air dried wood but it will still be there and cleaning it from the coils will be difficult if not impossible.

2) They only operate at low temperatures and that means very long drying times.

I hope this helps.

Of course, you know what you're talking about.  I've finally got my shed ready to put the dehumidifier in.  Reading the manual for this unit, it should only be operated at up to 90°.  As you mentioned, that's not gonna cut it.  I'm gonna plug it in in there and see how warm it gets.  At this time of year, I'm sure it's gonna hit 90 in no time.  Now that we are done with it at the office, we will probably sell it.  I will use my regular dehumidifier and plan to buy a Nyle or other.  

[GeneWengert-WoodDoc]

From time to time, a company will claim that their heat pump is much more efficient than another unit.  One company outside the USA claim that its basic measure of horsepower was larger than the horsepower of USA made dehumidifiers.  

However, differences in efficiency, from one DH unit to another DH, are very small.  To take air in a dry kiln or other structure at a given temperature and humidity, and then run the air through a heat pump (more technical term for a dehumidifier) must follow the Laws of Thermodynamics.  In fact, in a class about heat and mass transfer, the dehumidifier cycle is a classic problem that is well studied.  To get from one point (more humid) to another point (lower humidity), the path used  does not matter. 

When water vapor is condensed to a liquid, the energy released is fixed.

 The difference in operation efficiency can be only in the fan volume (and increased air volume costs a lot...double the air volume increases energy use by eight time) and the possible restrictions in the operating temperatures.  Also, with the environmental driven restrictions on the use of old Freon gases that destroyed the ozone layer in the air, the new, safer gases do not lubricate as well, so compressor life is reduced.  Also, acidic acid in wood does attack the metal fins used, so special coatings are often used to prolong the DH life.

Incidentally, in the USA, there are only two large compressor manufacturers.  This makes servicing quite simple.  The gas used in the compressor limits the temperature range.  For best overall drying efficiency, the best gas is one that allows the compressor to work at 150 F.  This temperature allows for rapid drying especially at low MCs.

A simple rule of thumb about lumber drying, is that KD lumber has a value increase of $200 to $300 per MBF.  This is adequate to make a nice profit.  It also means that the more lumber that is dried per year, the larger the profit.  So, drying speed is related directly to profit.  So, this means a 150 F operation, compared to 110 F, although more expensive initially will pay for itself quickly.  Also note that faster drying is achieved by better air drying so that the wettest lumber coming into the kiln is lower.

[firefighter ontheside]

It makes sense.  Thanks for the info.  Buying a Nyle or Woodmizer in the future will be my goal.  I had the little household dh in the shed for about 12 hours.  It raised the temp from 79 to 87. It lowered the rh from about 80 down to about 47.  There's about 3" of water in the pan.  I will be running a tube thru the wall to prevent from having to drain the pan.  I turned the thing off this morning.  It will be interesting to see how temp and rh change in 12 hours with dh off.  My door and walls are sealed well, but I may need to do better with the breaker panel and lights in ceiling.

[doc henderson]

how are you monitoring it.  of course both will change throughout the day and temps.  mine will read the daily high and low for both humidity and temp.  might just run the de-humidifier at night.  mine only works down to about 40% and when the temp goes up it is often less than that.  at night the temp drops and the relative humidity goes up, and that is when you can pull some moisture.

[firefighter ontheside]

I have a little digital thermometer/hygrometer that does just what you said.  It records current and also highs and lows of both.  I'm not planning to run a heater at all, just the dh and fans.  Maybe in cooler weather I can run the larger unit without overheating.  I will only be putting air dried lumber in there.

[GeneWengert-WoodDoc]

I expect that any community bank would give you a loan to get a NYLE.  As you make money, you can pay off the loan, or use the profit to get a new truck, or throw a big, social distance party.  It is best not to spend cash on hardware, as cash can be used to buy green lumber, logs, etc.  most drying operations are profitable but have cash flow issues their first year or two.

[firefighter ontheside]

I finally got that big dh home and into the shed.  I turned it on in there and it has raised the temp almost 10 deg in an hour.  It will be at 90 soon.  It also lowered the rh in there very quickly.  

 It occurred to me, what about a thermostat that turns the unit off at 90 and back on at something like 85.  I would have fans running constantly.

[Walnut Beast]

Just remember it doesn't matter what situation or problem that comes up. Your still responsible for that loan regardless. 

[doc henderson]

I see you are going to distill some wiskey too?!

[firefighter ontheside]

I see you are going to distill some wiskey too?!

Yes, it does say home brew.  Hmm.

[firefighter ontheside]

Just remember it doesn't matter what situation or problem that comes up. Your still responsible for that loan regardless.

Though I appreciate the idea of getting a loan for the Nyle, I will not be doing that.  If this was my main employment I certainly would, but this is a side gig and I'm fine with developing it slowly.  I also do a lot of woodworking too.  I'm behind on those as it is.  I am still a Fulltime Fire dept battalion chief.

[Don P]

Just pay attention to that 10 amp rating on the inkbird. I happen to know they let out the magic smoke easily  :D It still doesn't look like it is protected and most outlet strips kick at 15 amps so it might be worth getting and wiring in a 10 amp breaker on the inkbird, google, just like the lighted switch ones you see on outlet strips just 10A, and then the inkbird switches a higher amp relay that your big DH is plugged into.

I got their basic panel mount type version that does the same thing for about 1/3 that price and made up my own pigtails and plugs, all official like, housed in a plastic screw carton.

[firefighter ontheside]

That's probably a good idea.  I did note the 10 amp rating.  The dh I have says 7.9 amps, so I figured that would be enough safety margin.  I think I saw another option that was rated for 12a.

[firefighter ontheside]

@Don P I ordered the ink bird.  It will be here tomorrow.  I put lumber in there this morning.  The dh is running, but will quickly get too warm.

[Don P]

I dug out one of the ones I made. A friend was using the one you got for running heating mats for under trays in a greenhouse. She plugged in one more mat and that was that. I saw this one and found the little red 10A breaker/switch, kind of crazy that they make them without that protection, and then wired up an outlet that devices can plug into. We set up another one to run a cooler, these ones will work for heating or cooling and read in F or C, my brain does not work in C so that was one thing I was looking for.



 

[firefighter ontheside]

Wow, that's a great thing Don.  Nice work.