Blowing Cold Air

Using carbon dioxide for a compressed air source has many uses — it even doubles as a fire extinguisher for this bucket of flaming gasoline. Click here for video of backcountry fire extinguisher action.

I’ve always liked having compressed air available around the house and in the backcountry. It’s super useful for everything from winter backcountry skiing access drives to summer Jeep trails, as both types of motoring may require airing down tires then re-inflating for the highway. To that end I’ve run a variety of small electric compressors in our vehicles over the years — useful for filling tires (including bicycles), cleaning dust off things such as cameras, and more.

Automotive style twelve volt electric compressors are problematic little beasts. A good one is expensive — and only the pricey ones put out the kind of volume that makes them versatile tools. More, the powerful 12 volt units draw so much amperage you could possibly need an alternator upgrade to run one. You can mount a belt driven compressor on a car engine, but the amount of niggling that requires generally indicates someone with too much time (and not to mention money) on their hands.

But there is a solution.

During recent years Jeepers have become fond of carrying a tank of compressed carbon dioxide. With the correct pressure regulator a 10 lb. C02 tank will last through quite a bit of use, and a 5 lb tank is even a viable solution if you’re not planning on filling monster tires. When you run low on gas, you get the tank filled at a welding supply business, fire extinguisher company or a 4×4 customizer who has a “fill station” that moves liquid gas from a larger tank and adds a bit of compression while doing so.

There are two price options with CO2 tanks. You can go with a top-line Powertank brand rig that looks slick and has an expensive pressure regulator, or you can go budget and simply attach a fixed pressure regulator to any C02 tank.

Our budget CO2 tank mounted on Rumble Bee. It’s portable, so we’ll also have a bracket in our other TAVs (trailhead approach vehicles) and swap it around depending on what we’re driving.

I went the budget route since we already had a good 5 lb tank used for welding. The fixed 150 psi regulator was $50.00, and I already had the fittings and hose we’d been using for our small electric compressor. I also bought a tank bracket, but you could secure the tank with hose clamps or bungie cords. The rig with a fixed regulator works great.

Besides inflating tires and putting out fires, the best thing about having available compressed air is being able to dust and clean with a blower gun. It works well for cameras, but requires a good pressure regulator and 12 or more feet of hose so the CO2 doesn’t blow out hard enough to damage sensitive gear, and can warm up in the hose to a non damaging temperature before exiting. Expensive tanks have an adjustable regulator on the tank. In our case I installed an inexpensive one on the blow gun.

The boys at CODE 4×4 in Rifle, Colorado will fill CO2 tanks for a reasonable price. While the equipment required for tank filling does cost a bit, the actual gas costs pennies to fill a 5 or 10 pound tank. Shop around for fill price, as some outfits price gouge on this.

Safety note: If you’ve been around compressed gas (scuba, welding or otherwise), you know about the safety issues. If the valve breaks off a compressed gas tank it can become a rocket propelled projectile. It’s said that CO2 tanks are safer because they’re basically filled with liquid dry ice that has to boil off to make gas, thus they have much less force during an explosive decompression. Nonetheless, care is the order of the day with any tanked compressed gas. More, contact with a sudden outgas of CO2 can cause severe frostbite. For those reasons, if you’re carrying a CO2 tank in an automobile it should be secured with a bomb proof clamp or strap system that’s strong enough as to stay stable during heavy jostling such as in an accident. Our tank is mounted in the rear area of our Jeep, far enough away from the front passenger seat as to be safe in the event the valve was broken or accidentally opened. Another safety issue with CO2 tanks is that they have a pressure release valve that can sometimes blow if the tank is recently filled and gets hot. When the valve blows it is loud and startling, as well as blowing a blast of frostbite inducing cold CO2. Thus, CO2 tanks should be mounted such that if the valve blows it is facing away from people seated in the vehicle.