Keeping your food cold

From Nomad Life Wiki
(Redirected from Refrigeration)

Keeping your food cold is an important part of life on the road for most nomads, and there are a few ways to do it. Refrigeration is the most common, with several different types of refrigerators available depending on your needs and your setup. Some people simply use coolers and keep them stocked with ice. Some nomads choose foods that don't need to be kept cold and are careful not to make leftovers.

This page discusses methods for keeping your food cold in your vehicle.

Coolers

Coolers are one option for keeping your food cold while living on the road. Most people who live on the road full time switch to actual refrigerators, but coolers are still a good option for a lot of people. It depends on your needs, your available power, and other factors.  Continue reading …

Refrigerators

  • Benefits
    • Can keep food at food-safe or frozen temperatures without constant attention, and in any ambient temperature
    • No need to acquire ice or refreeze ice packs as with a cooler
    • No meltwater to deal with
    • 12v fridges designed for mobile use do not use large amounts of power
  • Drawbacks
    • Must have access to an electrical system in your vehicle
    • High initial cost, especially for non-residential 12v fridges designed for mobile use
    • Power usage may be an issue, especially for residential 120v or 220v fridges which require an inverter and may not be as well insulated
    • Propane fridges (not generally recommended) must be level to function and have other drawbacks
    • If plugged in to your vehicle's starter battery (not recommended), some cheaper units may drain your starter battery too much to start your vehicle

Refrigerators move heat from inside the box to outside the box, so that heat must be ventilated; ensure any vents exhaust into open area. Cooling performance may be enhanced by adding fans to move more air across the condenser.[1] and dusting components regularly.[2] Cold retention can be enhanced by adding insulation in the form of foam sheets or insulative covers made for the cooler.

Conventional front loading (or "upright") refrigerators are square or tall rectangles shaped like residential refrigerators. They stand up and have a door that opens forward, allowing direct access from a walkway. Space above the unit remains usable. Many people find this style of fridge easier to load and unload, with easier access to all contents. Unless latched or well secured, the door may sometimes swing open in transit. Items may shift and fall out when the door is opened. Also, cold air spills out of the fridge when the door is opened; the air must then be re-chilled which leads to higher power consumption.

Top loading

A 45-liter 12v refrigerator mounted in a drawer in a Volkswagen T6 LWB.[3]

Top loading refrigerators are usually low rectangles shaped like coolers. These are generally more efficient and use less power overall since cold air tends to stay put when the door is open and does not need to be re-chilled, but electricity needed for re-cooling air is fairly minimal[4]. Top-loaders can be filled to capacity more easily. The door will not swing open in transit and may not need to be latched. You may need to dig for food that's buried under other items, and it's easier for things to get lost/overlooked, or crushed (especially soft fruits). The space above the unit is unusable due to the door opening up, unless the unit is placed in a slide-out drawer or similar, or if a hinged work surface is placed above the fridge.

Check amps drawn [by the fridge] over 24 hours, much more important when boondocking than purchase price.[5]

12v compressor refrigerators become the standard way to chill food in solar-equipped vans. The main types of compressor fridges common in 'dwelling setups are:

  • Sawafuji-style compressor - This compressor has one moving part and is energy efficient with low startup current.[13] This kind of fridge is least likely to be damaged by rough use in the outback. Drawbacks: initial expense, the oscillating piston can be noisy. Brands include Engel[14], Arctic Cat[15], Engel MT35F[16][17]

Note that using a compressor fridge for refrigeration vs. freezing can have vastly different power requirements: "I use a pair of 65 qt Whynter units, one as a fridge, one a freezer. The freezer uses somewhere around 4 to 5 times the power that the fridge uses. Keeping the fridge at 40F is fairly easy, keeping the same unit at 0F is another story."[21]

The Engel MT series (MT35, MT45) are reported to have very low current draw due to clever cooling airflow design.[22]

I store leftovers in pint and quart mason jars, which stand up fine in the [Alpicool] 15L [flat lid version]. Longneck beers are slightly too tall. Since glass is heavy and harder to compact for trash removal I buy beer in cans anyhow. 16oz tallboys do fit. <-- the info discerning gentlemen need to know[23]

Alternative refrigeration

Due to advances in batteries and 12v mobile fridges, these methods are waning in popularity:

120v or 220v AC fridges, designed for AC power and residential use, have a lower initial cost and are widely available in a variety of sizes. However, they are not designed for mobile use, are typically only available in front-loading, are typically not optimized for power use, are often not well-insulated, and require constant use of an inverter. Inverters have power losses of their own, meaning additional power use will be required. If you have plenty of power in your vehicle, however, the lower initial cost may be attractive enough to offset the other disadvantages. [24][25]

Absorption fridges or propane fridges (propane-powered ammonia cycle) were popular in RVs because they used minimal power to run the ignitor, control board, fans if any. This type of fridge had to to be quite level so the ammonia cycle cooling would work by gravity; there is no pump.[26] Using one out of level could damage the cooling unit. Absorption units are rare in vandwelling setups due to size, expense, and need for exterior venting.

Peltier cooling is generally not recommended because it uses a lot of power and does so 100% of the time. A typical Peltier cooler might run 4-5A continuously whereas a compressor cooler might run 5A 30% of the time and turn off the rest of the time. The 100% duty cycle issue can be alleviated by wiring in a 12v thermostat, assuming it would ever get cold enough to shut off. Peltier coolers can only cool to ~30-40F below the ambient temperature, which may not be a problem if the ambient is 80F or less. (For best results avoid putting hot or even warmer-than-ambient items in the cooler. Use a fan on the item until it is room temp before placing in cooler.) Most units lack thermostats and so can accidentally freeze food if ambient temps are low enough. Read the manual before purchase to see how long it can be run at a stretch; fans are a common failure point when run 24/7. Possible use cases for Peltier coolers: you have a surplus of power (hooked up to shore power, have a large solar installation, or are running your heavy loads on opportunity circuit); you are in an area where ambient is less than 80F and the cooler has a thermostat; you want to chill nonperishable items like water, beer, etc., or semi-perishables like cheese and salami; or you already own one and run it on a Low Voltage Disconnect so it doesn't run down your batteries.

Using low outside temperatures, in areas with low humidity and a significant day/night temperature differential, you may be able to cool or even freeze cooler packs and water bottles; leave them outside overnight and put them back in the cooler in the morning.


Some or all of the content on this page was originally sourced from RVWiki

  1. http://www.cheaprvliving.com/forums/Thread-Ventilation-Fan-Vent-ThinkTank-Calling-out-SternWake?pid=87077#pid87077
  2. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=199289#pid199289
  3. For image credits, open image and click More Details
  4. http://www.promasterforum.com/forum/showpost.php?p=215513&postcount=19, https://www.reddit.com/r/skoolies/comments/17nswxl/experience_with_fridge_chest_vs_standing/k7u9evj/
  5. http://www.cheaprvliving.com/forums/Thread-Less-expensive-12-volt-fridge-recommendations?pid=294809#pid294809
  6. http://www.cheaprvliving.com/forums/Thread-Ventilation-Fan-Vent-ThinkTank-Calling-out-SternWake?pid=87077#pid87077
  7. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=202485#pid202485
  8. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=199259#pid199259
  9. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=202913#pid202913
  10. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=199262#pid199262
  11. https://www.reddit.com/r/overlanding/comments/o8orti/newbie_question_on_jackery_bluetti_portable_power/h37nb5r/
  12. https://www.reddit.com/r/overlanding/comments/o8orti/newbie_question_on_jackery_bluetti_portable_power/h36aiad/
  13. http://www.sawafuji.co.jp/english/tech/shindou.html
  14. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=200967#pid200967
  15. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=202485#pid202485
  16. https://www.reddit.com/r/vandwellers/comments/hgrlex/how_much_energy_do_i_ned_to_run_a_fridgecooler/fw5pt0r/
  17. https://www.reddit.com/r/overlanding/comments/o8orti/newbie_question_on_jackery_bluetti_portable_power/h39l92r/
  18. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=200523#pid200523
  19. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=200756#pid200756
  20. http://www.cheaprvliving.com/forums/Thread-Best-Fridge-for-the-Money?pid=206399#pid206399
  21. http://www.cheaprvliving.com/forums/Thread-Please-help-place-my-panel-order?pid=304673#pid304673
  22. http://www.cheaprvliving.com/forums/showthread.php?tid=28169&pid=355948#pid355948
  23. https://www.reddit.com/r/vandwellers/comments/f68tji/lowest_consumption_coolbox/fi3wcav/
  24. https://www.reddit.com/r/vandwellers/search?q=dorm+OR+120v+fridge&restrict_sr=on&include_over_18=on&sort=relevance&t=all
  25. https://duckduckgo.com/?t=ffab&q=site%3Avanlivingforum.com+%22dorm+fridge%22&ia=web
  26. http://www.doityourselfrv.com/know-rig-level-enough-rv-refrigerator-work-properly/