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TerraMex:
Well, he stated clearly that an achievable scenario for the ground radiador would be 8 ºC (see previous posts). Also that he will be using peltiers. Now depends on the peltiers , but 12º isn't that far off for a heavy pelted WC given his ground radiator. And if the (auto) radiator comes before or after the cooling loop (preferably before to maximize the dehumidifier effect). Lots of If's like i've said before.
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The 8*C number was the minimum, with a range of 8-10*C. Since we are talking about Summer humidity, I'm assuming the upper #, but it doesn't matter that much, since changing just shifts all the temps ~ the same amount. Also per BR's spec, the rad comes AFTER the blocks / pelts, which per his temp numbers the blocks will be on average 2-4*C colder than the Rad. (I don't know why we keep arguing about BR's #'s on each post, they don't change... :shrug: )
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o, it will have the exact same RH of the heated air IF no condensation/evaporation occurs in the heating element and/or exaust of the Dehumidifier. It has already removed an amout of water from the air, the heater doesn't remove any more (not even it's job). Water vapour doesnt "disappear" with temperature shifts. It has to condensate , or water has to evaporate to change de current RH. Thus de Dehumidifier purpose. If the heating element is shut down, the air will exit cold, but with the same RH, but different dew point.
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I agree the water vapour isn't dissapearing, but the air temperature is changing. As I have said before, if one has a box of air at a given temp and RH, then cools the air (but not to the dew point), the RH goes UP. If instead, one heats the box, then the RH goes DOWN
If the air cools to at (or below) the dew point then condensation will occur, but ONLY enough to lower the RH to the point where the dew point of the now cold air is below the ambient temp, but the RH of the cooled air is going to be effectively saturated so long as it is cooled.
One of my key assumptions is that the air coming through the rad will be cooled to something close to the rad temperature since the airflow will be low. (If the airflow were higher, then you would still have condensation on the rad, but not as much air temp change so more dehumidification effect would be occurring) I also make the assumption that the air temp will not change significantly between the rad area and the block area.
If the air coming through the rad is close to the rad temp, then it will have a high RH for air of that temperature. When that already cold, humid air hits the slightly lower temp blocks, then the blocks might be just enough colder for ADDITIONAL condensation to occur.
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But i already understood that. But again, the difference is the dew point. How cold are the blocks and tubes ? Dunno. One of key issues.
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I agree it's a key issue. If they are above the dewpoint of the cold moist air coming off the rad, then there is no problem. If they are below, then there is a problem. My opinion is that since per BR's spec, they SHOULD be colder than the rad, the risk is considerable.
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The difference is that BR's rewarmer has no comparison to a rewarmer from the dehumidifier. It's only purpose is to enforce convection currents which won't happen normaly given the cold air at the base. If the
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In the design as BR proposes, I agree, the rewarmer doesn't do anything to the RH in the computer chamber, which I see as a problem.
In my proposed alternative, the rewarmer still drives the convection currents, it just now ALSO serves to effectively lower the RH (and thus the dewpoint), hopefully enough to the point where further condensation on the cold blocks will not occur.
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Skoddelos:
I suggest you take a look inside your refrigerator. Hmm, not much condensation at the groceries, right? But in the back you can see some sort of plate with plenty condensed water. The water condeses there because the plate is the coldest place inside the frigde.
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Actually Skoddelos, if the air is humid enough, you WILL initially get condensation on all the stuff in the fridge, especially if it isn't a self defrost model.
After that, you have a semi-sealed box, where the water vapour condensing on the plate is effectively removed, lowering the RH of the air in the fridge below the dewpoint of the groceries, but not that of the plate. Since it's now drier, the water that was condensed on the groceries will evaporate back into the air, leaving just what condensed on the plate.
Gooserider