Why your food trailer is so hot inside, and what fixes it
Short answer
A food trailer overheats because the cook line adds heat while the hood exhausts the cooled air, so a single rooftop unit sized for an empty box cannot keep up. For scale, Georgia's state bid spec for an 8.5x16 concession trailer calls for a 15,000 BTU AC with a heat strip. Check two things before adding more AC: whether the hood has make-up air, and whether the RV unit's warranty covers food trailer use.
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The hood is fighting your air conditioner
Your exhaust hood is a big fan that pulls air out of the trailer and throws it outside. That air is the air your AC just cooled. Replacement air has to come from somewhere, and if the hood has no make-up air supply, it comes in hot through the service window and every gap.
Hood makers sell concession hoods with integrated exhaust and make-up air (HoodMart lists them alongside exhaust-only models). On a build, ask which one you are getting. On a trailer you already own, ask a hood installer whether make-up air can be added. Our food truck hood size and CFM calculator shows how much air your hood moves, which is the air your AC has to replace.
How much AC is enough
There is no single answer, because a coffee trailer and a fryer trailer of the same size have very different heat loads. One published reference point: a Georgia state bid spec for an 8.5x16 tandem-axle concession trailer lists a 15,000 BTU AC with a heat strip.
On the Good Sam forum, an owner of a 26 ft concession trailer asked how to add AC and heat to a box that had none. The replies went where they always go: the size of the trailer is only part of it, and what you cook decides the rest. Give your builder the full appliance list and hours of operation and ask them to size the AC for that, in writing.
The RV air conditioner warranty catch
Many food trailers use RV rooftop units because they fit the roof and run on 120 V. Read the warranty first. Atwood's AC warranty says the unit is designed for use in recreational vehicles and that any other use, unless authorized in writing, voids the warranty. A retailer Q&A says Advent Air will not cover units on food trucks or enclosed trailers.
Not every brand is the same, and retailer answers are not policy. Get the manufacturer's written answer for your exact model before you buy, especially if the unit will run all day next to a fryer.
Every BTU is generator load
An AC unit is often the biggest electrical load on the trailer, and it starts hard. Add a second unit and you may need a bigger generator or shore power to run it. Then the generator gets louder, which is its own problem at markets.
Before adding AC, run the new load through our food truck generator size calculator. It is cheaper to find out now that you need a bigger generator than after the breaker trips during lunch.
Cheaper fixes to try first
Shade the trailer and park it so the service window faces away from afternoon sun when you can. Turn the hood on when you cook (NFPA 96 requires it, section 12.1.1) but do not leave it on high when the line is idle. Keep the hood filters clean so it is not running harder than it needs to.
Check the insulation and roof. Some trailers are built with little or none. On a new build, tell the builder you work summers in the South and ask what goes in the walls and roof.
Getting it right on a new build
Put the climate details in your plan: the menu, the cook line, the hours, the region, and whether you want make-up air on the hood. Lay out the trailer in the free 3D studio, then send it to up to 4 builders through Trailer3D and compare how each one sizes cooling.
Questions
What size air conditioner does a food truck need?
It depends on the cooking load as much as the size. For reference, a Georgia state bid spec for an 8.5x16 concession trailer calls for a 15,000 BTU AC with heat strip.
Why is my food trailer so hot even with AC?
The exhaust hood pulls cooled air out, and without make-up air, hot outside air replaces it. Fryers and griddles add heat on top.
Can I put an RV air conditioner on a food truck?
Physically yes, but check the warranty. Atwood's warranty covers RV use only unless authorized in writing, and a retailer reports Advent Air excludes food trucks.
Will adding AC overload my generator?
It can. AC is often the largest load on the trailer. Check the new total with a generator size calculator before installing.
Sources
- BidNet Direct: Georgia concession trailer solicitation
- Good Sam Community: Adding an AC/heater to my Haulmark concession trailer
- etrailer: Can an Advent Air RV air conditioner be used on a food truck
- etrailer: Food truck rated RV air conditioner
- ManualsLib: Atwood air conditioner limited warranty
- HoodMart: Concession hood with integrated exhaust and make-up air
- NFPA: Food Truck Safety fact sheet (hosted by North Davis Fire District)
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