How Long Will a 20lb Propane Tank Run an RV Fridge?

When you’re out camping off-grid, there are only three ways to keep your food cold: propane, solar, or the hum of a generator. And if you’ve ever tried to enjoy a sunset next to an Onan, you already know which one kills the vibe.

That’s why gas absorption refrigerators are far from dead — they’re one of the most efficient, low-maintenance, and quiet solutions for the traveling RVer who actually likes to get away from hookups and noise.

How Propane RV Refrigerators Work

Gas absorption refrigerators (like those from Norcold and Dometic) don’t rely on compressors or moving parts. Instead, they use a heat source — a small propane flame — to drive a chemical process that circulates ammonia and hydrogen through coils. This allows you to run a normally heavily power demanding appliance with next to NO power.

They’re especially popular with boondockers because they can run for weeks on just a small tank of propane.

So, How Long Will a 20lb Propane Tank Last?

On average, a 20-pound propane tank (about 4.7 gallons of propane) can power a typical RV absorption refrigerator for around 10 to 14 days, depending on your setup and habits.
Here’s what affects your burn rate:

• Ambient temperature – Hotter days make your fridge work harder.

• Thermostat setting – Cranked all the way down? Expect shorter runtimes.

• Fridge size – Larger models naturally use more propane.

• Door usage – The more you open the door, the more propane you’ll burn.

If you’re running other propane appliances (like your water heater, stove, or furnace) off the same tank, expect your runtime to drop accordingly.

Why Absorption Fridges Still Make Sense

Modern 12V compressor fridges are great — but they demand serious solar panels and battery storage to keep up, especially in hot weather or cloudy conditions. If your goal is to camp off-grid longer without firing up your generator, propane wins for simplicity and peace of mind.

Propane refrigerators:
✅ Run quietly
✅ Use no battery power while cooling
✅ Are reliable and time-tested
✅ Perfect for long-term boondocking

When you combine that kind of freedom with the right maintenance and parts, these systems can last decades.

Tips for Maximizing Efficiency

1. Level your RV – Absorption systems need gravity to circulate fluids properly.

   • This is really something that needs to be done ALL the time. Gas absorption refrigerators are gravity operated, always be aware of this.

2. Pre-cool before your trip – Get the fridge cold on shore power before switching to propane.

3. Add a small fridge fan – Helps move air inside for better cooling.

4. Check your burner and flu – A clean burner means efficient flame and lower propane use.

   • The best way to clean your burner is to disconnect, soak in 90% alcohol overnight, and then blow out with compressed air. Treat your burners well, they don't last forever without maintenance.

Bottom Line

If you’re camping off-grid, a propane RV refrigerator is still one of the best tools for energy independence. A 20-lb tank can easily keep your fridge running for a week or two — and you’ll never have to listen to that generator again while watching the sunset.