Propane without pain II: Some safety checks and tricks to reduce LP use

Last time we talked about the nature of propane gas, and made a few points about taking care of propane storage cylinders. We’re back again to postulate on other propane peculiarities.

LP gas is a highly concentrated substance—there’s an awful lot of energy packed into that little container. Just how much? Glad you asked! From the technical side, there are roughly 91,000 BTUs (British thermal units) in a gallon of LP. So how does this work out? The typical RV refrigerator burner runs off about 5,000 per hour. That would mean over 18 hours of full-blown operating time on a gallon—but of course, unless you’re in a really hot climate, your fridge will be switching off and on.

Big consumers of propane are water heaters and furnaces. A 25,000 BTU (measured at input) furnace will run off five gallons of LP in that same 18-hour period.. Long showers are costly: A six-gallon RV water heater eats up 12,000 BTUs of running time. Here are some hints on cutting down the use of LP:

In warmer weather, switch your water heater valve to “pilot” (assuming you don't have electronic ignition) and let the pilot light keep the water warm. Some report that with judicious use of showers they can actually keep from lighting off that main burner and let the pilot do it all.

When shopping for a new furnace, compare the input BTU figures to the output—if 85 percent or more of your heat is going into your RV, that’s pretty good efficiency. But to make your LP go almost 100 percent, consider using a “blue flame” or catalytic style heater—almost 100 percent efficiency, and no use of 12-volt power to run a blower fan.

Out on the road you may find not everything sold as propane is the same. In a few areas, particularly in parts of Mexico, the product sold as propane has a higher proportion of butane gas than that sold in most areas of the U.S. That’s not usually a problem, as higher butane content LP burns just as well as that made up with lesser concentrations of butane. A problem can creep up if you take the “more butane in the mix” LP to colder climates. Where the ambient air temperature is below freezing, butane will not vaporize correctly, which can leave you with an inoperative gas system. If you gas up in Mexico, you’re best off using up the load before you head to the colder areas of the states.

R and T De Maris

Drive with the valves open or closed? We’ve never seen a definitive study, but some tell us they do. Others forswear having the refrigerator cold while motoring, telling us they feel a lot safer with the LP turned off. We used to be of the latter camp: If we were out of camp, the valves were closed. Then we started motoring through the desert country in summertime and found that here was an exception to our old maxim: “Keep the reefer door shut, it’ll stay cold enough.”

Yes, it’s nice having the food cold, and not fearing a case of food poisoning. At the same time, there is that bit of dread. The old “what ifs” keep flowing: What if we forget to shut off that refrigerator when we pull into a gas station, and the worst thing happens? What if we get pushed off the road by a big truck and we tip the unit over, and an LP line breaks? A disaster is the answer to both of those “what ifs.” Wherever possible, we prefer to run with our appliances turned off, and the gas valves closed.

If you decide to run with your valves open, then ALWAYS stop before you get into a refueling station of any kind (gas or LP) and TURN OFF any gas fired appliances. Standing pilots or automatic ignition, either way, the pilot or the spark from ignition can really create an explosion hazard under the right circumstances.

It's wise to do an annual LP system safety check.  Using soapy water solution (heavy on the dish soap) or an LP gas sniffer, check all gas connections inside and outside your rig. If you have (and know how to use) a manometer (gas pressure gauge), then check to make sure your LP gas regulator is doing its job correctly. Don’t have one? Call around and find out what RV service facility will give you a good rate to test your regulator, and give you some peace of mind.

Check out all gas-using appliances for insect encroachment. Some wasps think the odor of LP is like honey to their cousins. They’ll build little nests in RV vents, causing appliance malfunctions, or worse, allowing for a buildup of deadly carbon monoxide gas inside your rig.

LP gas is a wonderful tool for RVers. Use it with care, observe appropriate safety cautions, and you’ll have plenty of good times in your RV.

Propane without pain. Part 1: Simple things to keep you safe

public domain courtesy wikimedia.org

The old joke talks about the fellow unexpectedly hurtling toward earth after being tossed out of a plane. Struggling to figure out the rip cord on his parachute, he spots another man flying upward toward him, frying pan in hand. “Hey!” he calls out. “Do you know anything about parachutes?”

“Nope!” shouts the upwardly moving character. “Do you know anything about propane stoves?”

It’s likely that if you ever find yourself in a parachute, you’ll have had a lot more training on rip cords than many who take up RVing get on propane safety. In this first part of a two parter, we'll take up a few simple things about LP (for “liquid petroleum,” more commonly called propane) that can make your RVing experiences easier and safer.

Under pressure, propane is a liquid—colorless and odorless. “But, it stinks when they refill my propane tank!” you say. Sure enough, an odorant is added to commercial propane. But here’s a warning: Not everyone can smell the odorant; a cold or sinus or olfactory problem can eliminate this warning odor. Test your RV’s gas detector regularly.

While water boils at 212 degrees, propane boils at -50 degrees. Mind you, propane in your tank is definitely under pressure. As that pressure is released, the liquid absorbs heat. If you watch the tank refilling process, you’ll see a stream of what looks like steam coming out of a small valve in the tank. Stick your finger in it and you’ll find it not hot like steam but extremely cold—enough to freeze your skin.

Propane, unlike natural gas used in many homes, is heavier than air. This may cause you to think if you get a propane leak in your rig that it will sink to the floor. But moving air currents will stir the propane up, causing it to mix with the air, putting it anywhere, and that could mean harm if it finds a source of ignition. If you think you have a gas leak, GET OUT OF THE RIG, and don’t turn on the light to see the door. Leave the door open, allowing the gas to dissipate.

Happily, propane requires oxygen to burn, and in a very narrow range of proportion. Too much propane to air, or too little, it won’t burn. For some, that can bring on a lax attitude toward safety: They’ve smoked around an area where tanks were being filled, they’ve fueled up the tow vehicle while the propane valves were open, blah, blah, blah. “And I’ve never had a problem!” It only takes one time of having the right propane-to-air mixture with a source of ignition to have your first—and last—problem with propane.

The upshot?  Don’t use a match to check for propane leaks. Don’t leave your pilot lights lit, or appliances with automatic ignition turned on when fueling your vehicle or your propane bottles.

To carry and safely contain propane, RVs are equipped with LP containers. Technically speaking, only a motorhome has a propane “tank,” permanently mounted on the rig. Trailers and campers have portable cylinders that have different safety regulations to live up to. Portable containers are generally painted white. This isn’t just to make your rig look pretty: Propane is highly responsive to heat, so painting your container white will help it reflect light, hence staying cooler. We’ll come back to how important this is in a bit. Keeping your LP containers painted and tending to scratches will keep you safer.

Regulations mandate that 12 years after manufacture, portable cylinders must be inspected and “recertified” as safe. That recertification must be repeated every five years after that. Not every LP refilling station is sticky about this, and there are plenty of conscientious LP retailers who get blasted by an irate RVer whenever they refuse to refill a container that’s out of date. Still, they’re looking out for your safety, and it doesn’t cost much to have a cylinder recertified.

One more point on the subject of safety: Motorhomes and nearly all other RVs have tanks fitted with valves that stop the intake of gas when full. On portable containers (on trailers), they’re called OPD valves, for “overfill protection devices.” Propane station attendants remind us that these are mechanical devices, and they’re about as accurate as the gas gauge on your car. It is possible (more likely probable) to overfill an LP container equipped with an OPD valve. This can become a serious problem. How so?

Every LP tank is equipped with a pressure relief valve. Because of the highly expansive nature of LP gas (its volume increases dramatically with increasing temperature), here’s a scenario you should never forget. One day you and your fifth wheel are in Montana, getting ready to get out of that cold nastiness and head south for the winter. Your LP guy fills up your tank, and carelessly overfills it. A couple of days later, you’re in Arizona, and the temperature is much higher. LP in the “full” tank expands dramatically. The gas pressure relief valve “pops off,” allowing a large volume of LP to suddenly flood into the nearby atmosphere, where Joe Schmo is walking by, lit cigarette in his mouth. You get the picture.

The only SAFE way to fill an LP tank is by either weight (which few stations do) or by opening a little valve on the tank called a 20 percent valve (some call it a spit valve) while filling the tank. When liquid propane begins to “spit” out of the 20 percent valve, the attendant should IMMEDIATELY STOP filling the tank. Filling beyond this point is completely unsafe. We’ve had more than one argument with a careless station worker over this matter, but we’re the ones that have to ride in the rig and suffer any consequences of stupidity.

More next time.

Spring into action -- get your RV air conditioner ready to chill Part 2 of 2

Last time we discussed how to handle the "inside the rig" part of air conditioner maintenance. Now we move to the part of the job will take you up topside. You’ll need a sturdy ladder. As a general rule to protect your roof, don’t walk on it. This particularly applies to older rigs that don’t have a solid plywood deck under the roofing material. Best to put a "kneeler board" across the rafters and knee walk across it to reach the ac unit.

At the unit, check out the condition of the condenser fins. These little guys provide a broad surface for outside air to draw away the heat pumped out from the inside of your rig. If they’re bent, like the two photos show, they’ll need to be straightened out to remove that heat efficiently. A thin knife or screwdriver blade may help. Or you can use an air conditioner fin comb--a specialty tool that can help if the fins are not too badly bent. We once spent countless hours with a knife blade straightening out a whole mess of fins that had been completely bent over. We also tried working with a fin comb, and if the fins are badly bent, it was actually quicker to straighten the devils with a knife and screwdriver.

While on the roof, inspect the a/c unit "shroud," the protective cover. These are prone to taking hits from branches; plastic ones often get damaged by UV rays. Sometimes they can be fixed with fiberglass cloth and resin--check out a boat supply or auto parts house. If you repair cracks on the inside of the shroud, the work will likely be secure, but not obvious to outside observers. A more expensive solution is installing a replacement shroud.

The shroud should be securely mounted, you’ll find screws around the bottom of the shroud that tie it to the ac unit itself. Too much zeal with a screwdriver can easily crack the shroud around the mounting holes, rendering it useless. Take it easy! Firm, but not over-torqued is the rule for installing a shroud.

Take the screws out and carefully remove the shroud. Again, make sure you have the power disconnected--you don’t want the ac unit to start up while you’re poking around "under the hood." You’ll be looking for the evaporator--it looks like a small automotive radiator. Take a brush and gently remove dust from it--if you have an air compressor, gently blast the dust out with pressurized air. Getting the dust out will make your system more efficient.

Now check out the motor. Some ac units will have oil holes, possibly covered with a rubber plug. Other ac motors are permanently sealed and don’t require lubrication. For the former, carefully remove the plug and add 3 or 4 drops of oil--some recommend "three in one" oil for the job. Over-oiling is worse than not oiling! Replace the rubber plug(s).

Put the shroud back on, while keeping the torque down to a dull roar.

Now it’s time to test the system. Be sure you have sufficient power--most a/c units require your RV be hooked up to at least a 30 amp service. If you don’t have the power, wait until you get somewhere where a 30 amp circuit is available. Turn on the unit and let her rip. You should have plenty of cold air delivery. Enjoy a cool summer!

photos: R&T De Maris

Spring into action -- get your RV air conditioner ready to chill Part 1 of 2

El Niño has rattled the populace. Depending on where you are, either you're experiencing the misery of continued cold, snow, and ice, or you're elsewhere, seeking shade and ice tea. Take heart, you folk out in the cold country – summer will come. And for the rest of us – it's high time we got the RV air conditioner ready for use. Actually, it may be past time.

To that end, we herewith provide the first of a two-part series on the hands-on of air conditioner maintenance. We’ll address the most common of RV air conditioning systems--the roof mounted a/c unit. Exposed as it is to the elements and low-hanging branches, the roof-mounted unit is prey to a lot of problems. But let’s start "inside" first.

The easiest part of the assignment is simply cleaning or replacing air filters. Check your owner’s manual to find instructions for getting the filter out of the unit – typically by removing a couple of screws and pulling a grill loose to access the filter. This filter, although cleaned in the last few weeks, is in serious need of cleaning again.

Some a/c unit filters can simply be washed in warm, soapy dishwater, thoroughly dried, and reinstalled. In use, washable filters should be removed and cleaned a couple of times a month if used in dusty areas; once a season should be enough elsewhere.

Some a/c filters are not washable but must be replaced. Here’s a thought: You can replace nearly any a/c filter with an after-market "electrostatic" filter that is said to capture more dust and pollen than typical OEM filters. We’ve never actually tested them out, but if you’ve got twenty bucks to check the theory out, visit a Camping World store for these super filters.

While you’re working with the filter, check out your unit’s ducting. Some rigs have simple metal channels to deliver chilled air; others may use heat distribution hoses. If you can, it’s a good time to vacuum out your ducts while servicing the filter.

So much for filters. If you’re feeling a bit more adventurous, check out unit security. We’re not talking about somebody stealing your a/c unit, but rather having the thing get loose and fall off your rig. An a/c unit is bolted onto your rig roof top and, generally speaking, the mounting bolts come down through the roof and snug up inside the rig. Often these can be accessed by removing the inside trim that surrounds the unit. Be sure to disconnect the power before puling this trim – you may expose electrical fittings you don’t want to get your fingers into. Once you spot the mounting hardware, make sure it’s tight. Incidentally, water leaking into your RV through the a/c unit can sometimes be traced to loose mounting bolts.

We'll get onto the outside work in our next installment.