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  1. #1
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    Jun 2000
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    Portable air conditioners

    Would like comments from anyone who has experience with any portable air conditioner that goes inside a room with only the one small duct discharging to the outside. As this example: http://www.target.com/Sunpentown-000...archPage=1&rh=

    Although non technical users gave great reviews on many of the websites, I am optimistic. Since the unit dose not take air from the outside to cool the condenser coil, the inside air that is taken out of the room will be replaced by infiltrating outside air which will contain heat and moisture. The condensation is used to coil the evaporator (as does most window units) but after the water evaporates on the coil is that moisture put back into the room or discharged out of the building?
    Mike Edwards

  2. #2
    Join Date
    May 2000
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    Indianapolis, IN, USA
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    Definitely don't get a 1 pipe. You are right, hot air leaking in can overpower the cooling capacity of the unit and make things WORSE! 2 pipe only!

  3. #3
    Join Date
    May 2006
    Location
    Wisconsin
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    Not good!

    I made the mistake of buying a 1 pipe a few years ago. It was 9,000 BTU. It did (barely) cool a tiny bedroom, but it was very damp and clammy feeling due to humidity infiltration. I got rid of it shortly thereafter. A few hundred bucks wasted...............

  4. #4
    Join Date
    Sep 2009
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    Portable unit performance

    I have the same question. I just purchased A 14,000 BTU portable air conditioner/ Dehumidifier to replace an old 11,000 BTU window unit that failed. I thought it odd that the new portable unit has two ducts. One intake and one exhaust. I can see the obviouse reason for the exhaust as it blows out hot air like a clothes dryer. What I do not agree with is the intake duct. Why would I want to take in fresh hot humid polluted outdoor air and introduce it inside? Wouldn't it be better to just keep cooling the same indoor air over and over again like the window unit I just replaced? The old window unit seemed to do a better job. This new portable unit blows 38 degres out the outlet but it just doesn't seem to work as well as the old window unit it replaced. So I am disconnecting the intake duct from the window and will see how that works. Not sure if the intake duct has any affect on cooling the condensor and if it will adversely affect the peformance of the unit by affecting the boiling point of the freon, which is R-410A. One thing is for sure, the room feels slightly humid compared to my old window unit.


    Any thoughts on this.

  5. #5
    Join Date
    May 2006
    Location
    Wisconsin
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    Thumbs down leave it connected

    If you disconnect the inlet pipe it will use already cooled room air to cool the condenser, create negative room pressure. That will increase infiltration and actually RAISE the humidity levels. It is advisable to use both pipes. The intake pipe is not putting outdoor air into the room. It is cooling the condenser and then being exhausted out the other pipe. I ended up throwing mine away and buying a much cheaper window unit that actually does work much better. Oh, well.......live and learn.

  6. #6
    Join Date
    Feb 2005
    Location
    Barrie, Ontario
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    Deja vu
    Is this a Fabreze moment? C.Y.D. I'm voting white elephant. 2.

  7. #7
    Join Date
    Jun 2010
    Location
    Hershey Highway
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    I sell Stuff - Never Buy by Brand Buy by Service

  8. #8
    Join Date
    Apr 2010
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    I recently did some pre emptive maintenance on an outdated SPT portable air-conditioner (9k btu/h). It belongs to my gf's family and I thought it'd be nice to take a look at it since they had mentioned the lack of proper cooling. Basically, blew the condenser with co2 and added some R22 (brazed a tiny leak). The unit is working great with the exception of the inevitable shut-down fallowed by this error code (E4 fault) which periodically recurs. I know that for this situation it is counter-intuitive to go ahead and perform a major repair, and I can only presume that the problem lays on the control board/mother board. Though, it is only a presumption. Has anyone ever worked on this particular manufacturer or just happen to own one? Does E4 fault indicate a control board issue or does the problem lay somewhere else?

  9. #9
    Join Date
    Feb 2001
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    Quote Originally Posted by grtpumpkin View Post
    I have the same question. I just purchased A 14,000 BTU portable air conditioner/ Dehumidifier to replace an old 11,000 BTU window unit that failed. I thought it odd that the new portable unit has two ducts. One intake and one exhaust. I can see the obviouse reason for the exhaust as it blows out hot air like a clothes dryer. What I do not agree with is the intake duct. Why would I want to take in fresh hot humid polluted outdoor air and introduce it inside? Wouldn't it be better to just keep cooling the same indoor air over and over again like the window unit I just replaced? The old window unit seemed to do a better job. This new portable unit blows 38 degres out the outlet but it just doesn't seem to work as well as the old window unit it replaced. So I am disconnecting the intake duct from the window and will see how that works. Not sure if the intake duct has any affect on cooling the condensor and if it will adversely affect the peformance of the unit by affecting the boiling point of the freon, which is R-410A. One thing is for sure, the room feels slightly humid compared to my old window unit.


    Any thoughts on this.
    the intake pipe doesn't bring air into the room. It is the air used to cool the condenser and is exhausted back out.
    its basically a heat exchanger section separate from the indoor air.
    one thing I see done a lot is using 4" dryer vent to lenghten the run of outside air. that will not work, you need to use the same size pipe and long runs of it cause the unit to overheat and shut down the compressor.
    for best results they have to near a window only using the short runs of fles pipe supplied with the unit.
    Hey cockroach, don't bug me!

  10. #10
    Join Date
    Jun 2019
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    Quote Originally Posted by jakester65 View Post
    If you disconnect the inlet pipe it will use already cooled room air to cool the condenser, create negative room pressure. That will increase infiltration and actually RAISE the humidity levels. It is advisable to use both pipes. The intake pipe is not putting outdoor air into the room. It is cooling the condenser and then being exhausted out the other pipe. I ended up throwing mine away and buying a good protable air conditions that actually does work much better. Oh, well.......live and learn.
    That's right, a double hose portable AC cools the room more quickly than a single hose. Also, if you are sensitive to noise, you'd better choose a quiet AC. Otherwise you may have to apply for a return because of its noisy.

  11. #11
    Join Date
    Oct 2019
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    USA, Seattle currently
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    Quote Originally Posted by me View Post
    Would like comments from anyone who has experience with any portable air conditioner that goes inside a room with only the one small duct discharging to the outside.

    Although non technical users gave great reviews on many of the websites, I am optimistic. Since the unit dose not take air from the outside to cool the condenser coil, the inside air that is taken out of the room will be replaced by infiltrating outside air which will contain heat and moisture. The condensation is used to coil the evaporator (as does most window units) but after the water evaporates on the coil is that moisture put back into the room or discharged out of the building?
    In our previous apartment, before we put in central air, we used two portable units purchased a couple of years apart. First one had a single vent hose, second one had two.
    Single hose blows the hot air out, but hot outside air infiltrates to make up, so the central air has to work a little harder.
    Two hoses has outside air intake and hot air exhaust, so the portable unit does all the work. A factor to consider.

    You also reminded me of another thing to watch out for though: my portable unit had a high temperature cutoff for the condenser coils. When the intake air was over 100-105 degrees it would shut off due to not being able to cool the condenser sufficiently. Since that kind of heat doesn't happen in our location very often it wasn't too much of a problem, but in AZ I'd imagine it'd make the unit useless.
    That's one of those little fine print things that they don't say on the box, only in the back of the manual.

  12. #12
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    Jan 2010
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    This thread is 9 years old, hello

  13. #13
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    Oct 2019
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    Quote Originally Posted by VTP99 View Post
    This thread is 9 years old, hello
    Oops! Got distracted by Victornik's post, my mistake.
    Call him a necroposter, not me!

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