Why such a large AC unit?

Discussion in 'Heating / Cooling Systems' started by kcormier19, Dec 31, 2020.

  1. kcormier19

    kcormier19 Member

    Messages:
    95
    Likes Received:
    39
    Joined:
    Sep 12, 2017
    Location:
    massachusetts
    My 1999 Coleman Cheyenne Camper has a 15000 BTU air conditioner on the roof. I can cool my entire 400 square foot living room with a 5000 BTU window air conditioner that uses a lot less power. Aside from the fact that a pop up canvas is porous and therefore may require more cooling, why do pop up campers need such large AC units?. I have seen some hardside campers such as a Scamp or the little snoozy that have traditional window AC units built into them that run on only 15 amps. I see the advantage of this is that you can run them off a much smaller and quieter generator. I have seen a few pop ups with people have put Macy's in them that are also 5000 BTU units. But I am still confused as to why 15000 BTUs is required?
     
  2. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

    Messages:
    8,772
    Likes Received:
    6,159
    Joined:
    May 31, 2018
    Location:
    Nj
    Its probably a 13500 or 11500 unit. Something like that, i never saw a 15000 btu unit. They have them because they need them. If they needed a 5000 btu wall unit the manufacturer wouldn't put an oversized one in rhat cost 8x as much. Your living room isn't a tent thats directly heated by the sun. You have a roof, and air space under that with gable and ridge vents to take out the hot air. Addtionally you have walls , even with no insulation have an air space that will insulate the area. A pup has non of that. So direct radiant heat, that keeps ot hot in the sun. A shade and pugs will help that but not enough to offset the need for a larger type AC. Addtionally there is the air leakage you speak of.
     
    firepit, WrkrBee, Snow and 3 others like this.
  3. tfischer

    tfischer A bad day camping beats a good day at the office Gold Supporting Member

    Messages:
    4,300
    Likes Received:
    1,816
    Joined:
    May 21, 2014
    Location:
    Plymouth (Minneapolis) Minnesota
    You answered your own question. Pup is not only not insulated at all, but gets baked by the sun.

    We remodeled our kitchen a few years back and they tore the ceiling and insulation out. This was July, and standing in that area you could feel the roof radiating intense heat down... and that was through shingles and plywood sheathing.
     
    firepit and Sjm9911 like this.
  4. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah Gold Supporting Member

    Messages:
    6,266
    Likes Received:
    3,157
    Joined:
    Oct 10, 2013
    Location:
    Northern Virginia
    I will tell you, your popup is going to need every bit of those BTUs in the summer especially if your in the south. Add humidity and it's only worse. In the summer I keep my shades drawn and use popup gizmos to help keep the sun's heat away in addition to the AC unit. I camped once when it was 100 degrees and 75% humidity with only a 5000 BTU window unit in my popup and I was dying inside. Especially in the bunkends. So to say I've upgraded since then.
     
    southern gal and Sjm9911 like this.
  5. theseus

    theseus Living the Darkside... Silver Supporting Member

    Messages:
    2,986
    Likes Received:
    524
    Joined:
    Feb 6, 2007
    Location:
    Centerville, OH
    I put a 5000 btu A/C unit in my 86 Coleman Columbia. It only seemed to make a difference at night. The rest of the day it was hotter inside than outside. Real roof top 13.5K BTU was number 1 on the list when we were looking for its replacement.
     
    Sjm9911 likes this.
  6. firepit

    firepit Well-Known Member

    Messages:
    1,708
    Likes Received:
    2,498
    Joined:
    Feb 26, 2020
    Location:
    Nebraska Go Big Red
    You need to smile...As others have said...You got a great set up.
    The bigger...The better...Mine 13500 And I have Gizmos and Reflectix
    to help with keeping it cool.
    Pitch a tent and sit in it mid day...That's basically what a pop up is.
     
    silvermickey2002 and Sjm9911 like this.
  7. WrkrBee

    WrkrBee Well-Known Member Silver Supporting Member

    Messages:
    5,229
    Likes Received:
    2,579
    Joined:
    May 23, 2018
    Location:
    South Carolina
    Cool Cube 5000 in our Aliner. Sad.
    Size matters.
     
    Sjm9911 likes this.
  8. silvermickey2002

    silvermickey2002 Morris County, NJ Gold Supporting Member

    Messages:
    4,826
    Likes Received:
    633
    Joined:
    Sep 11, 2008
    Location:
    Morris County, NJ
    We have a 13.5 BTU unit on the roof of our pup. When at our site during the day and it's hot I don't think a 5,000 BTU unit would do anything!!! The 13.5 unit would at least cycle on and off. The 5,000 unit would run constantly. So which one is actually saving power!!!
     
    Sjm9911 likes this.
  9. Sneezer

    Sneezer Well-Known Member

    Messages:
    2,587
    Likes Received:
    1,428
    Joined:
    Aug 8, 2015
    Location:
    DFW, TX
    I have 13.5 BTU unit. In tx summers it barely keeps up in 100 degree heat. One trip the power center failed and I had an 8k BTU portable and I might as well have had nothing. With no insulation these pups turn into a sauna.
     
    firepit and Sjm9911 like this.
  10. Family Travels

    Family Travels Member Gold Supporting Member

    Messages:
    99
    Likes Received:
    53
    Joined:
    Oct 26, 2019
    Location:
    Hampshire, Illinois
    I've got a rooftop unit and it's almost like it does nothing during the summer. Pups don't do well with no insulation. I've purchased Gizmos and I'm going to cut out some Reflectix for the windows for next year hoping that will make a huge difference.
     
    Sjm9911 likes this.
  11. silvermickey2002

    silvermickey2002 Morris County, NJ Gold Supporting Member

    Messages:
    4,826
    Likes Received:
    633
    Joined:
    Sep 11, 2008
    Location:
    Morris County, NJ
    The Reflectix should help. We ran into a family that had it in all the windows. The gentleman said it made a big difference in the summer heat. This was in South Jersey in June. He also had Gizmos. He also had a small fan moving the air around which also does help. We do that!
     
    Sjm9911 likes this.
  12. Sneezer

    Sneezer Well-Known Member

    Messages:
    2,587
    Likes Received:
    1,428
    Joined:
    Aug 8, 2015
    Location:
    DFW, TX
    My experience in TX summer heat is to have good shade all day if possible. I have pugs on both bunks and the dinette slide. I also slide some pool noodles between the pugs and the canvas to help create an air gap. Reflectix in the windows for the bunks, and the dinette/kitchen. Awning deployed to ensure shade on that side. A/C cranked down to Hi Cool, and a couple oscillating fans to help with air distribution. With good shade I can keep the interior in the 70s when it is 100+ outside. With the 2nd 8k portable A/C running I am down to 68-72, and it has gotten into the 50s at night if I leave both running. In full sun with no shade I can still keep it in the 70s with both units. With no shade and only the roof one it will only get down to mid 80s during the day. Nights are always comfortable though.

    I used to work out of it during the day while taking my son to a summer day camp, so I had to make sure it was comfortable inside so I could get my work done and save those precious vacation days. Eventually I hope to add shade awnings to the otherr three sides - they do this in Australia for their pups, and it should work equally well here to further regulate temps. Heat soak is the biggest enemy since there is no insulation with a canvas camper.
     
  13. davido

    davido Well-Known Member

    Messages:
    988
    Likes Received:
    290
    Joined:
    Jul 17, 2014
    You're probably just mis-remembering.

    Here is a link to a Dometic 15KBTU model: https://www.amazon.com/Dometic-Black-Conditioners-B59516-XX1J0-Brisk/dp/B00VZ547NU

    The most common denominations for RVs are 13500 and 15000.
     
  14. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

    Messages:
    8,772
    Likes Received:
    6,159
    Joined:
    May 31, 2018
    Location:
    Nj
    I might be, but i thought they all came with the colman mach 1 or 3 during those years. As mine had the 3 and it was one of there biggest pop ups, i figured that was the biggist. Eaither way you need a bigger ac in a pup. It could have been replaced with you dominic one , who knows.
    * edited to add during those years, so around the year 2000. *
     
  15. jeepster04

    jeepster04 Active Member

    Messages:
    138
    Likes Received:
    78
    Joined:
    Nov 23, 2010
    Some people like to parking lot camp. On a hot sunny day you'll need it.

    Ive always camped in the woods so even on 90F days, the A/C makes the popup an icebox.
     

Share This Page