Puff Cigar Discussion Forums
MEMBER CIGAR REVIEWS | STAFF CIGAR REVIEWS | CIGAR VIDEOS | ONE ON ONE INTERVIEWS | CIGAR NEWS | CIGAR FORUMS | PIPES | LIFESTYLE | CONTACT

User Tag List

Results 1 to 15 of 15

Relative Humidity vs. Absolute Humidity in Re: Temperature

This is a discussion on Relative Humidity vs. Absolute Humidity in Re: Temperature within the General Cigar Discussion forums, part of the The Cigar Lounges at Puff category; Admittedly, I was constantly lost in science class. I am still trying to wrap my head around rH in relation ...

  
  1. #1

    Alpha Puffer Fish Laynard's Avatar


     

    Relative Humidity vs. Absolute Humidity in Re: Temperature

    Admittedly, I was constantly lost in science class. I am still trying to wrap my head around rH in relation to temperature. I know that if the absolute humidity (moisture content) in the air remains the same, lowering the temperature will raise the relative humidity towards the dew point. This would be tragic for cigar storage. But our hygrometers measure relative humidity, not absolute humidity. So let's say I have 70% rH at 21*C (70*F). That gives me just over 13 whatever the unit of air content is. But 70%/18*C (64*F) is more like 10.8. Which at 21*C is closer to 60% relative humidity. So storing at 70%/64*F has the same absolute humidity as storing at 60%/70*F. Do cigars care about absolute humidity at all? I would think the actually moisture content of the air can be more damaging than the relative humidity, and the measurement of relative humidity is reliant on the assumption that we store at 21*C. This is considering that mold typically appears at higher rH AND temperature. Also, this is why 40% rH in the winter seems dryer than 40% rH in the summer. (It does to me at least.) But, again, I barely passed science class. I don't even know what science class would cover this...

    Sorry if this post makes no sense. Now you know what it's like to be inside my mind.
    To smoke is human; to smoke cigars, divine.

  2. #2

    True Derelict Fuzzy's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Layne, you need to chill out! If the cigars are stored at the rh you want them to be at and they smoke well with little issues such as burn/harshness,,, ENJOY!!!! Stressing over this hobby probably takes something away from the enjoyment.

    If you must ponder this issue, do not forget ambient rh
    I don't always drink beer,,,
    OK, yes I do

  3. #3

    Wildman Dual-500's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Cigars care about Relative Humidity. 500 cubic inch normally aspirated pro stock drag racing engines care about grains of water in the air or absolute moisture content.

    Get a digital hygrometer, calibration pack. Calibrate it, then play with moisture content a bit. Run through the region of 62% to 70% to see what you like best with your smokes. Allow ~2 weeks at each moisture point for things to normalize. Keep the temparature of you storage setup as constant as possible.

    Like Fuzzy commented, don't overthink things - just enjoy em'!

  4. #4

    Alpha Puffer Fish Laynard's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by Dual-500 View Post
    Keep the temparature of you storage setup as constant as possible.
    This is exactly what makes me think absolute humidity is a factor and relative humidity is in assumption of temperature. Plus, it's easier to measure rH.

    I know it shouldn't be this technical, but I enjoy over thinking things. Instead of those science classes, I took way too many philosophy courses. It's like Socrates and the pig: I can't wallow in blissful ignorance anymore.
    To smoke is human; to smoke cigars, divine.

  5. #5

    Young Puffer Fish wallydog's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Think of it this way .... the molecules in a cubic foot of air at a low temperature are smaller or more compact than the same molecules at a higher temperature of the same pressure so the colder air doesn't have the capacity to hold as much moisture as the warmer air . This is what makes the humidity relative to the temperature .

  6. #6

    Wildman Dual-500's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    ^ Yep. RH will move with temperature - all other things being equal. Keep temperature as constant as makes sense and RH will be fine.

    RH is what the cigars respond to.

  7. #7

    Alpha Puffer Fish Laynard's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by wallydog View Post
    Think of it this way .... the molecules in a cubic foot of air at a low temperature are smaller or more compact than the same molecules at a higher temperature of the same pressure so the colder air doesn't have the capacity to hold as much moisture as the warmer air . This is what makes the humidity relative to the temperature .
    Right. So at a lower temp, the same relative humidity would actually have less moisture. This makes me think that even at 70%, if it is too cold, your cigars can actually dry out.
    To smoke is human; to smoke cigars, divine.

  8. #8

    Young Puffer Fish


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by Laynard View Post
    Right. So at a lower temp, the same relative humidity would actually have less moisture. This makes me think that even at 70%, if it is too cold, your cigars can actually dry out.
    You are completely right about the grains of moisture in the air. But where you are loosing it is in the movement of moisture. Moisture moves from a high RH to low RH. That is often why people store things in a cooler or freezer. Take a moist steak or slice of bread or even a glass of water, store one on your kitchen counter and the other in the fridge and test the difference. The reason the fridge keeps things moist, is because the drop in temperature increases the RH.

    A lot of people think fridges add moisture, when the really remove moisture (condensation on the evaporator coil). So... with that being said, you will not dry out your cigar at 70% RH in cold temps.

  9. #9

    Young Puffer Fish wallydog's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by Laynard View Post
    Right. So at a lower temp, the same relative humidity would actually have less moisture. This makes me think that even at 70%, if it is too cold, your cigars can actually dry out.
    You would think , but the molecules are smaller and cannot absorb more if the cigars are also around 70 % at the same temperature. Its a standoff .

  10. #10

    Alpha Puffer Fish Laynard's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Ok. I still don't get it, but I'll take everyone's word for it for now. Like i said, I understand lowering temp increase RH given a constant absolute humidity, like in the fridge example, but I don't understand how lowering the RH and thus the absolute humidity in relation to the temp (to maintain the same RH despite the lower temp) doesn't effect the cigars. I believe it has to do with this movement and molecule size you both speak of. So it was chemistry class that failed me. I just still have this nagging feeling this is related to the 70/70 myth somehow.
    To smoke is human; to smoke cigars, divine.

  11. #11

    Young Puffer Fish


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Using everyday examples, another way to think about it...

    Moisture has a POTENTIAL to move based on RH difference. Again moving from high to low. The bigger the differences in RH, the more potential the moisture has to move. Example, hair dryer. The hair is wet and saturated (100% RH). You could blow hot or cold air across it. The hot air at X amount of grains has a very low RH, causing a large RH difference and hence the moisture moves quickly. Cold air at the same amount of grains, will have a higher RH, and a smaller RH difference and the moisture will move slower. Dishwasher, and laundry dryers use the same principle.

    This is obviously a pretty simple way of explaining a much more complicated process.

  12. #12

    Wildman Dual-500's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    The 70/70 numbers are convenient and easy to remember and work. They are not however, necessarily optimum values. They are not target values, but maximum recommended values.

    Temperature of 70 degrees is the highest recommended storage temperature - above which propagation of mold and bugs is more likely to occur. Below 70 degrees is just fine. Constant temperature, 70 F or below is the ticket - within reason.

    Relative Humidity or RH is the same. 70% is the highest recommended RH point to store cigars in. Many experienced smokers use a lower RH value. I prefer my stash at 65% RH. I keep the humidor at 65-67% RH and 69 degrees F year round.

  13. #13

    Alpha Puffer Fish Laynard's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    I think I'm starting to get it. With those 67%/69* numbers, if we dropped the temp to 64* the humidity would be around 78% given the g/m3 of water content. I think we can agree that is too high. But that same amount of water content in the air is fine at 69*. So as you guys have been saying all along, absolute humidity is irrelevant, it is RH that matters. And constant temp just prevents the RH from swinging because the absolute humidity will probably remain the same. I think I fully beat this dead horse. Thanks for helping my mind work through this.
    To smoke is human; to smoke cigars, divine.

  14. #14

    Young Puffer Fish


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by Laynard View Post
    I think I'm starting to get it. With those 67%/69* numbers, if we dropped the temp to 64* the humidity would be around 78% given the g/m3 of water content. I think we can agree that is too high. But that same amount of water content in the air is fine at 69*. So as you guys have been saying all along, absolute humidity is irrelevant, it is RH that matters. And constant temp just prevents the RH from swinging because the absolute humidity will probably remain the same. I think I fully beat this dead horse. Thanks for helping my mind work through this.
    You're all over it!

  15. #15

    Wildman Dual-500's Avatar


     

    Re: Relative Humidity vs. Absolute Humidity in Re: Temperature

    Quote Originally Posted by Laynard View Post
    I think I'm starting to get it. With those 67%/69* numbers, if we dropped the temp to 64* the humidity would be around 78% given the g/m3 of water content. I think we can agree that is too high. But that same amount of water content in the air is fine at 69*. So as you guys have been saying all along, absolute humidity is irrelevant, it is RH that matters. And constant temp just prevents the RH from swinging because the absolute humidity will probably remain the same. I think I fully beat this dead horse. Thanks for helping my mind work through this.
    Bingo! Ding ding ding ding ding ding ding ding ding!!!!!!

    That's ok bro and you are very welcome. Most of what little I know about cigars has come from other minds that were willing to share with me. It's appreciated and payed forward when appropriate. Good discussion is always a nice part of this hobby.

    I can observe exactly what you describe in the Wine Cooler (Wineador) that I setup. It has an external electronic temperature controller and humidity controller. The humidity controller reads almost in real time. So, when the temperature controller calls for a cool cycle from 70- F to 68 F, setpoint is 69 F. The compressor and internal fans kick on. The RH drops as the evaporator plate cools down and collects moisture. Then the compressor kicks back off after about 1 minute or less of run time. The RH has dropped about 15% and as the evaporator plate fans blow across it bringing it to ambient and drying any moisture collected on it in the form of condensation the RH climbs back up. It then raises up 2% to 3% higher than set point for a few minutes while temperature crawls back up to 69 F due to the air being cooler.

    If you're interested I posted a thread on the build in the Accessory section and it's called "Wineador Trial and Tribulations........part 2".
    Last edited by Dual-500; 01-19-2014 at 07:18 PM.


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •