Results 1 to 12 of 12
  1. #1
    Join Date
    Jan 2006
    Location
    plettenberg bay
    Posts
    26
    Rep Power
    0

    dehumuidification HELP



    there are hard and fast rules to everything in life and I sit with the hard problems and the clients that want things done fast!
    Does any body have experience with de-humidification with refrigeration units ?
    what is the maximum moisture removal versus machine size, coil size, and temperature ?

    My client wants to remove an estimated 6000 litres of water from 20 cubic meters of wood in 2 weeks flat.
    not only is he driving me mad with his self imposed "time limit" but everybody else in the factory, so far with a TFH4531 compressor we have managed to remove an estimated 2400 litres in 10 days, is there any way we could speed up the process? with the excisting unit?



  2. #2
    Join Date
    Sep 2005
    Location
    Singapore
    Age
    59
    Posts
    145
    Rep Power
    19

    Re: dehumuidification HELP

    Heat up the area to bring down the humidity?

  3. #3
    Join Date
    Mar 2006
    Location
    Merate (LC) - Italy
    Age
    53
    Posts
    2,549
    Rep Power
    24

    Re: dehumuidification HELP

    6000 liters in 24 days means 428 liters per day, or 17.8 liters per hour.
    That's the dehum capacity of a medium sized AHU treating air *alone*, set aside wood.

    I don't think it is possible with natural convection. I think the wood must be heavily warmed up, and even considering that, it may not be possible to convince wood to release that amount of water.

  4. #4
    Join Date
    Oct 2006
    Location
    Bucks, U.K.
    Age
    71
    Posts
    604
    Rep Power
    18

    Re: dehumuidification HELP

    I would have thought that its very much dependant upon the thickness of the pieces of wood, how they are stacked (open gaps) to allow airflow around the wood.
    Temperature and humidity of the circulating air are also major factors.
    I think that drying wood is a science in itself....if done too rapidly then it will crack and warp...the humidity of the chamber has to be carefully controlled and reduced gradually over time. Condenser heat can obviously be used to heat the chamber again provided it is controlled.

    I think you will need to research this carefully.

  5. #5
    Join Date
    Feb 2007
    Location
    UK
    Posts
    2,473
    Rep Power
    45

    Re: dehumuidification HELP

    The people to speak to is Munters,

    As mentioned above, it's not just to remove the moisture.

    As someone who grew up in the darkest woodlands of Sweden, I've seen quite a few "wood driers".
    Normally they consist of a heater and a sorpsion dehumidifier, no fridge stuff at all.

    Good luck,

  6. #6
    Join Date
    Jan 2006
    Location
    plettenberg bay
    Posts
    26
    Rep Power
    0

    Re: dehumuidification HELP

    OKAY
    the riddle has been solved as with refrigeration there are rules that have to be followed and adhered to otherwise you will be burning your fingers
    As I have done in the last two weeks!
    the rules are as follows
    1. thickness of the wood as in length versus breadth versus thickness
    2. the amount of heat required to heat the wood to realease the water
    3. the rejection of the excess heat created by the refrigeration process
    4. creating and maintaining a stable evaperator pressure to facilitate maximum moisture removal
    and bingo you follow the magic numbers (that took me 9hrs of googling to gleam from 7 different websites) to get to the fact that it is in fact possible to remove 6000 litres of water from a whole pile of timber, provided of course that you follow the rules!!!!!!
    So after checking through all the data that I had accumulated I did the sums and my little 19000Btu compressor has pulled 2480 litres of water in 10 days which was well within spec of the figures
    If any body has an interest or problem with the following they are more than welcome to contact me
    YIPPPEEE
    gonna go "bekruip" (leopard crawl) the bottle of red wine and celebrate!!!!

  7. #7
    Join Date
    Jan 2006
    Location
    Croatia
    Age
    68
    Posts
    2,263
    Rep Power
    31

    Re: dehumuidification HELP

    Hi, Andre Fridge

    Quote Originally Posted by andre_fridge View Post
    OKAY
    the riddle has been solved as with refrigeration there are rules that have to be followed and adhered to otherwise you will be burning your fingers
    As I have done in the last two weeks!
    the rules are as follows
    1. thickness of the wood as in length versus breadth versus thickness
    2. the amount of heat required to heat the wood to realease the water
    3. the rejection of the excess heat created by the refrigeration process
    4. creating and maintaining a stable evaperator pressure to facilitate maximum moisture removal
    and bingo you follow the magic numbers (that took me 9hrs of googling to gleam from 7 different websites) to get to the fact that it is in fact possible to remove 6000 litres of water from a whole pile of timber, provided of course that you follow the rules!!!!!!
    So after checking through all the data that I had accumulated I did the sums and my little 19000Btu compressor has pulled 2480 litres of water in 10 days which was well within spec of the figures
    If any body has an interest or problem with the following they are more than welcome to contact me
    YIPPPEEE
    gonna go "bekruip" (leopard crawl) the bottle of red wine and celebrate!!!!
    What about to share that with all of us in some general therms. Maybe some small example.

    Best regards, Josip

    It's impossible to make anything foolproof because fools are so ingenious...

    Don't ever underestimate the power of stupid people when they are in large groups.

    Please, don't teach me how to be stupid....
    No job is as important as to jeopardize the safety of you or those that you work with.

  8. #8
    Join Date
    Jan 2006
    Location
    plettenberg bay
    Posts
    26
    Rep Power
    0

    Re: dehumuidification HELP

    the "bekruiping" of the red wine went absolutely wonderfully!!!!!!!!!!!!!!!
    I will sit down and do a citation of the 'magic' numbers, but as of now my bed is calling as I have had far too much red wine, solved the worlds problems, and need some hard earned sleep!
    expect something over the week end
    till later

  9. #9
    Join Date
    Aug 2007
    Location
    South Korea
    Posts
    14
    Rep Power
    0

    Re: dehumuidification HELP

    Hi there....

    I'm trying to put together a similiar system for a littel different purpose....

    But I'm completely new to heat pump tech....

    Could you possibly describe your system?

    I see your using a pump thats rated for r22, what about the rest of the setup?

    Valve type, condensor/evaporator specs etc...

    Any help will be greatly appreciated.

    Thanks,
    Michael

  10. #10
    Join Date
    Nov 2004
    Location
    perth australia
    Age
    77
    Posts
    14
    Rep Power
    0

    Cool Re: dehumuidification HELP

    Quote Originally Posted by andre_fridge View Post
    there are hard and fast rules to everything in life and I sit with the hard problems and the clients that want things done fast!
    Does any body have experience with de-humidification with refrigeration units ?
    what is the maximum moisture removal versus machine size, coil size, and temperature ?

    My client wants to remove an estimated 6000 litres of water from 20 cubic meters of wood in 2 weeks flat.
    not only is he driving me mad with his self imposed "time limit" but everybody else in the factory, so far with a TFH4531 compressor we have managed to remove an estimated 2400 litres in 10 days, is there any way we could speed up the process? with the excisting unit?
    Hi Andre.
    The moisture removel from timber is a trikey subject. If you remove the moisture too fast the timber will warp and twist which i am sure your client will not want, so impress upon him this fact. I do not have your conditions posted so i do not know how you are opperatining the system or your air circulation patten.
    The basic rule is the drier and warmer the air passing over the timber the more moisture it will pick up and if your coil is sized correctley you will get your maximum drying capacity.
    Are you passing the cooled air over the condensing unit to reheat it theres no moisture added by the hot air off the condenser. You should should aim for 30C minimum air onto the timber and the timber has to be stacked so as the air flows evenly over all sufaces or you will warp the timber. The slower you dry out timber the better the quality of the product.
    Get on the web and down load vaisala humidity calculator it,s a great programe and will be most help full to you. good luck Tony L.

  11. #11
    Join Date
    Oct 2003
    Location
    Belgium
    Age
    62
    Posts
    5,630
    Rep Power
    34

    Re: dehumuidification HELP

    Quote Originally Posted by The Viking View Post
    The people to speak to is Munters,
    As mentioned above, it's not just to remove the moisture.

    As someone who grew up in the darkest woodlands of Sweden, I've seen quite a few "wood driers".
    Normally they consist of a heater and a sorpsion dehumidifier, no fridge stuff at all.

    Good luck,
    We've made in the past many wood dryers with refrigeration units.
    How you think a Munters will react to the agrresive acid found in oak?
    The weel will detoriate after a while.
    But was the original question for wood. This wasn't mentioned in the first post.
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

  12. #12
    Join Date
    Oct 2003
    Location
    Belgium
    Age
    62
    Posts
    5,630
    Rep Power
    34

    Re: dehumuidification HELP

    We made some units with ambients of more then 60°C to dry oak (see other posts in this forum)
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

Posting Permissions

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