Forum Discussion

joshuajim's avatar
joshuajim
Explorer II
Sep 13, 2018

Wrong type of upper vent?

My Dometic 2652 located in a slide has never cooled well. With the addition of fans I have been able to keep the refer temp around 40 degrees. All systems have been checked and properly serviced.

Today I was looking at the upper vent. I noticed that it is the same as the lower vent. On the lower vent, the air enters and then is directed upward as proper flow would dictate. BUT on the upper vent the air has to turn 180 degrees downward before exiting. This seems totally wrong. I understand that the vents are designed to keep rain out, but the airflow is totally inteuuupted as it tries to flow out.

In addition, it looks like the free area is considerably less than a typical roof vent.

I wonder if a different type of upper vent would aid the air flow.
  • dougrainer's avatar
    dougrainer
    Nomad
    Sep 14, 2018
    joshuajim wrote:
    OP here. I've made the installation match to a T and even added the radiused baffle at the top, 3 fans on the evaporator and 2 fans sucking at the top and one on the interior fins. Maxed out the perimeter insulation and the door seal is good. I think I just got a bad refer from the get go.

    I still think that the upper vent is poorly designed. Hot air like to rise but when it hits the upper grill it has to desend and then meets cooler outside air which is denser. Not a good design. Probably works on most units but could be better.

    My unit has been running all day on direct connect electric and it still is only 42 with OAT at 92.


    In a slideout, you need to have at least 1 fan blowing straight out that upper door. Can you post a pic of the upper hole showing the back of the refer. I want to know how high up the condenser fins are in relation to the door cut out. Doug
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Sep 13, 2018
    There is a limit to how much "Cool" an absorption cooling system can provide. If it's too hot out. and too hot in and the sun is beating down on it. You may have an issue.

    Adding cooling fan(s) may help.. Mine is in the lower compartment blowing UP. I have a single Computer type fan (4") in the compartment. Tight fit. I may put in a 2nd one later. Blowing UP through the condenser and out the top. Mine is not in a slide so it blows out the roof. You can also put 'em in the top sucking air. but I like it better in the bottom where I don't have to climb a ladder.
  • fred42's avatar
    fred42
    Explorer
    Sep 13, 2018
    Does your unit have that sliding piece of plastic on the inside that is supposed to be a thermostat?
  • joshuajim's avatar
    joshuajim
    Explorer II
    Sep 13, 2018
    OP here. I've made the installation match to a T and even added the radiused baffle at the top, 3 fans on the evaporator and 2 fans sucking at the top and one on the interior fins. Maxed out the perimeter insulation and the door seal is good. I think I just got a bad refer from the get go.

    I still think that the upper vent is poorly designed. Hot air like to rise but when it hits the upper grill it has to desend and then meets cooler outside air which is denser. Not a good design. Probably works on most units but could be better.

    My unit has been running all day on direct connect electric and it still is only 42 with OAT at 92.
  • dougrainer's avatar
    dougrainer
    Nomad
    Sep 13, 2018
    I have worked on upwards of 200 slideout installed refers and the design of the upper door has never been a factor in getting the refer to cool correctly. What HAS been a factor is correct upper baffling to make sure that air flows out the door. Doug
  • William_Willard's avatar
    William_Willard
    Explorer
    Sep 13, 2018
    I had a Dometic 1402 refer in the slide-out of our 07 Monaco Camelot -- It never operated right even after several warranty attempts -- I had fan`s every where -- After 4 years I gave up & installed a residential Samsung frig -- No problems since -- Bill Willard
  • time2roll's avatar
    time2roll
    Nomad
    Sep 13, 2018
    What you probably need is a baffle to direct the airflow over the fins instead of just up the free space. Did this on my old pop-up with similar short chimney and it made a huge improvement.
  • ScottG's avatar
    ScottG
    Nomad
    Sep 13, 2018
    What you have is very normal.
    Another thing that's normal is for RV manufacturers to ignore the installation instructions in ragards to clearances and flue baffling.
    It would behoove you to pull the fridge and follow the install instructions to the letter.
    Also, I would create a radiused or angled flue to smooth the flow of air out the upper vent rather than the hard 90 degree it probably has to make now.
    If you can provide the chimney effect the manufacturer instructions describe and smooth the flow of air exiting the compartment, it will cool better.
  • JaxDad's avatar
    JaxDad
    Explorer III
    Sep 13, 2018
    Ditto the above, however......

    Mojave Desert vs Goodrich, MI might have a lot to do with it also.

    Bear in mind also, slow gentle air movement via convection isn't going to be slowed like high velocity air is.
  • Roger10378's avatar
    Roger10378
    Explorer II
    Sep 13, 2018
    I have never seen a different vent design on a refrigerator in a slide. My upper and lower vents are the same and I have no trouble with my refrigerator cooling. I think you need to look elsewhere for you problem.

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