Home Improvements & Air Conditioning » Portable Air Conditioners » Dehumidifier that is vented outside?

Dehumidifier that is vented outside?

Question:

Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers

True, but this isn’t adding up to any appreciable heat gain. I think he’s following the reverse logic of people thinking that leaving the refridgerator door open is going to cool the room down.

Response:

    If you were to vent the hot air outside, then you would be venting the dry air outside.  You would also be pulling hot humid air in to replace the air you vented out, so not only would the house get hotter, but it would get more humid.     If you want to cool and dehumidify, get an air conditioner. — Joseph E. Meehan 26 + 6 = 1  It’s Irish Math

– Hide quoted text — Show quoted text – I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there). The problem is that it consumes a lot of energy and blows hot air from the back. That by itself would be ok if not for the fact that the house is also being air conditioned, which means that I have to waste a lot of energy cooling the air that was just heated by the dehumidifier. So I was hoping to be able to find a dehumidifier that somehow vents hot air outside and not inside. Do such units exist? igor

Response:

I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there).

Instead of building a Rube Goldberg Device to deal with the heat, and extra energy, and condensation, and moisture, and constantly adding water to the tank, why not just go to the source. Cover the aquarium. If the tank is losing so much water that the humidity in an already air conditioned space is an issue, there is something wrong. And a dehumidifier is ~not~ going to fix it. Mike    http://www.newsfeed.com       The #1 Newsgroup Service in the World! —–= Over 100,000 Newsgroups – Unlimited Fast Downloads – 19 Servers =—–

Response:

– Hide quoted text — Show quoted text – I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there). Instead of building a Rube Goldberg Device to deal with the heat, and extra energy, and condensation, and moisture, and constantly adding water to the tank, why not just go to the source. Cover the aquarium. If the tank is losing so much water that the humidity in an already air conditioned space is an issue, there is something wrong. And a dehumidifier is ~not~ going to fix it. Mike

well, actually in a properly run reef tank, one encourages evaporation. it’s one of the easiest ways to increase the calcium supply to the tank, in that makeup water is actually a saturated solution of calcium hydroxide. another reason to encourage evaporation is for cooling without having to add an expensive and heat producing chiller. regards, charlie cave creek, az

Response:

Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers work in the desert). Darn it, I knew the scientific term for this just a few minutes ago :-( .

Heat of evaporation. And heat at the state change from liquid to frozen is heat of fusion. You might also be thinking of the term "latent heat" to describe the stored heat. Endothermic and exothermic.

No, and this shows how a little knowledge is a dangerous thing. Endothermis and exothermic refer to chemical reactions.  A TNT explosion is strongly exothermic, as is the gasoline combustion in your car engine; the reaction releases heat previously stored in the compounds. Sometimes you have to add energy to a process to ‘cook’ up a certain compound, that would be endothermic. -v.

Response:

Sure, but the centrail air conditioner would save a lot more energy than the extra energy that the dehumidifier would consume.

No, it would not.  Igor, you just don’t get it (perhaps your net name "ignoramus" is quite appropriate).  How do you think the de-humidifier dehumidifies?  How do you think an A/C cools?  Do you realize that an A/C also dehumidifies, and that the btu load on the A/C is partly to change room temperature, and also an additional load to condense out moisture (the "latent heat" part of the calc)? A dehumidifier works by cooling mist air to below its dew point, causing water to condense out.  Then you restore the heat to the air or else, if you exhausted the heat elsewhere, that room would just get colder and colder (and still be humid as the dew point drops and drops and the room stays at a high relative humidity) until getting to the performance limits of the equipment. Obviously, your basement needs more dehumidification than it does cooling, or you could just run your A/C until it was dehumidified. Ahh, why bother.. fart around with it all you want after a dozen people have tried to tell you, basically, that there is thermodynamic TANSTAAFL. -v.

Response:

Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers work in the desert). Darn it, I knew the scientific term for this just a few minutes ago :-( .

The scientific term is latent heat of formation, if memory serves.  Endothermic absorbs heat, exothermic releases heat. It’s been a while since chemistry class!

Response:

It produces exactly the amount of heat implied by its wattage.  If you get more or less, patent it. Venting outside (ie putting the hot coil outside) would turn it into an air conditioner and make it work harder since it couldn’t cool the hot coil with the cool air it just made. Venting the flow past the hot coil outside would dehumidify the outdoors. That’s the dried air you just made. — Ron Hardin On the internet, nobody knows you’re a jerk.

Response:

I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there). The problem is that it consumes a lot of energy and blows hot air from the back. That by itself would be ok if not for the fact that the house is also being air conditioned, which means that I have to waste a lot of energy cooling the air that was just heated by the dehumidifier. So I was hoping to be able to find a dehumidifier that somehow vents hot air outside and not inside. Do such units exist?

A dehumidifier is basically an A/C unit.  So, the hot air blowing out the back of it is a result of the air blowing out the front that has been cooled.  The only heat created is the incremental heat from running the unit itself.

Response:

A dehumidifier is basically an A/C unit.  So, the hot air blowing out the back of it is a result of the air blowing out the front that has been cooled.  The only heat created is the incremental heat from running the unit itself.

Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers work in the desert). Darn it, I knew the scientific term for this just a few minutes ago :-( . — There is no distinctly native American criminal class except Congress.                                               – Mark Twain

Response:

A dehumidifier is basically an A/C unit.  So, the hot air blowing out the back of it is a result of the air blowing out the front that has been cooled.  The only heat created is the incremental heat from running the unit itself. Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers work in the desert). Darn it, I knew the scientific term for this just a few minutes ago :-( .

Endothermic and exothermic. – Hide quoted text — Show quoted text – — There is no distinctly native American criminal class except Congress.                                               – Mark Twain

Response:

A dehumidifier is basically an A/C unit.  So, the hot air blowing out the back of it is a result of the air blowing out the front that has been cooled.  The only heat created is the incremental heat from running the unit itself. Actually, there is also heat released when you condense water (just as heat is absorbed when you evaporate water, thus why evaporative coolers work in the desert). Darn it, I knew the scientific term for this just a few minutes ago :-( . Endothermic and exothermic.

While the dictionary definitions support these adjectives, my experience is they are more often used to refer to chemical reactions as opposed to processes. I would have said "latent heat of condensation" and "latent heat of vaporization." "Latent heat" refers to heat either given off or absorbed such that no change in temperature occurs. Oak What is Usenet if not a poor improvement on Trivial Pursuit?

Response:

There is no dehumidifier will do that.  Dehumidifier venting the dryer/dehumidified air from the back and expecting it to vent the air outside the house seemed to defeat the purpose. However, if you installed an air conditioner for your basement it’ll do what you want which is dehumidify the air inside and venting the hot air outside. F. Chang – Hide quoted text — Show quoted text – I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there). The problem is that it consumes a lot of energy and blows hot air from the back. That by itself would be ok if not for the fact that the house is also being air conditioned, which means that I have to waste a lot of energy cooling the air that was just heated by the dehumidifier. So I was hoping to be able to find a dehumidifier that somehow vents hot air outside and not inside. Do such units exist? igor

Response:

… So I was hoping to be able to find a dehumidifier that somehow vents hot air outside and not inside. Do such units exist?

… No. They do not exist, at least not in the way that you are thinking. The typical dehumidifier works very much like an air conditioner. It cools the air coming in, condenses the water out of it, and then warms the air going out. Since it consumes power it also generates heat. Most of these units don’t produce a great deal of heat so you might want to see if yours needs service. You could hook up a humidistat to the unit to turn it on only when there is an excess of moisture in the air. This would reduce it’s run time and therefore the heat it generates. You could simply use a window or split air conditioner and it would vent the hot air outside but it would also cool the air inside and dehumidification would not be it’s primary designed purpose. You could also use a desiccant system of some kind. A typical one would use a desiccant wheel that air is blown through. The wheel would sit astride two air chambers. In one chamber the air is circulated through the desiccant to dry the air. In the other the air is heated to drive off the water from the desiccant. This heated and wet air is typically vented to the outside. The wheel is turned slowly so that the desiccant cycles from one side to the other on a periodic basis. Anthony

Response:

I used a portable air conditioner for my air conditioned humid basement room http://www.toyotomiusa.com/products/portableairconditioners/TID-2400.mv

– Hide quoted text — Show quoted text – I recently bought a dehumidifier for the basement, with the hope that it will reduce humidity in the basement (I have a fish tank there). The problem is that it consumes a lot of energy and blows hot air from the back. That by itself would be ok if not for the fact that the house is also being air conditioned, which means that I have to waste a lot of energy cooling the air that was just heated by the dehumidifier. So I was hoping to be able to find a dehumidifier that somehow vents hot air outside and not inside. Do such units exist? igor

Response:

Sure, but the centrail air conditioner would save a lot more energy than the extra energy that the dehumidifier would consume.

No, it would not.  Igor, you just don’t get it (perhaps your net name "ignoramus" is quite appropriate).  How do you think the de-humidifier dehumidifies?  How do you think an A/C cools?  Do you realize that an A/C also dehumidifies, and that the btu load on the A/C is partly to change room temperature, and also an additional load to condense out moisture (the "latent heat" part of the calc)? A dehumidifier works by cooling mist air to below its dew point, causing water to condense out.  Then you restore the heat to the air or else, if you exhausted the heat elsewhere, that room would just get colder and colder (and still be humid as the dew point drops and drops and the room stays at a high relative humidity) until getting to the performance limits of the equipment. Obviously, your basement needs more dehumidification than it does cooling, or you could just run your A/C until it was dehumidified. Ahh, why bother.. fart around with it all you want after a dozen people have tried to tell you, basically, that there is thermodynamic TANSTAAFL. -v.

Response:

Hi Igor5882, hope you are having a nice day On 13-Aug-02 At About 08:30:41, Igor5882 wrote to All  I I recently bought a dehumidifier for the basement, with the hope that  I it will reduce humidity in the basement (I have a fish tank there).  I The problem is that it consumes a lot of energy and blows hot air  I from the back. That by itself would be ok if not for the fact that  I the house is also being air conditioned, which means that I have to  I waste a lot of energy cooling the air that was just heated by the  I dehumidifier.  I So I was hoping to be able to find a dehumidifier that somehow vents  I hot air outside and not inside. Do such units exist?  I igor If you think about it this is not a good idea as you would be tossing the cooled air outside. as you vent the air it would be replaced by hot humid outside air.  -= HvacTech2 <=- .. "See this?  This is a copy; I want you to make me the original."- s.w.     ___ TagDude 0.92

Related Posts

Category Categories: Portable Air Conditioners | Comments No Comments »

Leave a Reply