Reefer Temp Control in Winter

Discussion in 'Refrigerated Trucking Forum' started by ZzYy, Jan 6, 2012.

  1. ampm wayne

    ampm wayne Heavy Load Member

    Jan 13, 2009
    You have to have a bulkhead in the trailer.

    For example if you need the front of the trailer to be 0 deg. You set your reefer at 0 deg. F. Load the frozen product.
    Then put up your bulk head leaving one hole open in the bulk head so some cold air can get to the product you want to keep at 34 deg. Load the chilled product.

    A lot of grocery loads are hauled this way.

    You seem to be worried about freezing product when the outside temp. is cold. Reefer trailers are well insulated.
  2. cadillacdude1975

    cadillacdude1975 Road Train Member

    Mar 20, 2010
    Chattanooga, TN
    well insulated and made a lot different from a conventional dry van. that is why so many drivers have weight issues with hauling a reefer. all that insulation and the aluminum floor add weight.
  3. ZzYy

    ZzYy Bobtail Member

    Jan 6, 2012
    Thanks guys. I guess frozen tomatoes wouldn't fare well if this split frozen/refrigerated setup didn't work well in outside temps of 10 degrees. The reefer trailer must indeed be insulated enough. Thanks for the insight. I am shipping a crate of liquid that shouldn't be frozen. It certainly won't be the FIRST one that fared fine in this configuration.
    Thanks again.
  4. pullingtrucker

    pullingtrucker Road Train Member

    Dec 21, 2008
    Fostoria, Ohio
    You wouldn't load tomatoes with a frozen load unless it is a very short run (less than a few hours). Tomatoes need the reefer on continous for the air flow around the fruit/veggies.

    Lets use my current load as a example: I got 6 pallets of frozen and 24 pallets of fresh (the fresh is pin wheeled and stacked all over to get it to fit...just the way I like to see my trailer:biggrin_2559:). I loaded the frozen and put up my bulkhead. Knowing what the weather temps, load temps, and how long the freight is going to be on the trailer helps determine how far the vents in the bulkhead are opened. After setting the vents I packed in the fresh pallets and set my unit to -5*. After a couple of hours the temps level out so you can get a true reading of what they are. My frozen is at -3 and the fresh is holding steady at about 27*...this is about perfect.

    Majority of frozen loads are hauled at 0* or lower so the unit won't run in the heat mode unless the inside temp gets lower than the set you don't have to worry about it heating even if the outside temp is 10*. The fresh product holds the "heat" (higher temp) for a long time if the bulkhead seals against the wall properly and the doors also seal. It is also helpful to have a rear vent door to check the air temp inside with a good calibrated thermometer. I prefer them compared to temp gun cause the temp gun only checks surface temps. Say your fresh temps get to low. All you have to do is raise the reefers set point to keep it from cycling to much. This will help the fresh temp stay steady or rise in temp. You have to remember that it will take a long time or very cold/hot air to change the product temp of a whole pallet.

    If you are still worried about freezing a product, then you can always use a pallet blanket and wrap it up tightly. I do this when I only have a few pallets of frozen that need to be on the tail of the trailer. The frozen pallets will hold there temps just fine even in the middle of summer. Some people also don't realize that not all products freeze at 32*. There are many manufactured products that freeze higher, but the majority are way lower. A pallet of beef can be put in a trailer for 2 days at 20* and it still won't be frozen. Temp safety is paramount, but many guys don't realize how sensitive or insensitive the products are that they have on the wagon.
    skoshi130 Thanks this.
  5. ZzYy

    ZzYy Bobtail Member

    Jan 6, 2012
    Great info. I will wrap my pallet in a thermo blanket and stop worrying about it !
  6. Crazy D

    Crazy D Medium Load Member

    Mar 18, 2011
    Get a spread. No worries.
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