Fun with Propane

When it comes to controlling temperatures in the tent, there are three season: the Hot Season (Summer), the Cold Season (Winter), and the Damn-It's-Cold-In-The-Morning Season (Spring and Autumn). Spring and Autumn in Virginia can bring morning temperatures down to the 40s. That's still too warm to light up the wood stove, but it's uncomfortably cool when you crawl out of bed in the morning. So from September through November, and again in the Spring, I need some sort of space heater to warm things up.

Last year, I used a kerosene heater to drive out the morning chill. It worked well, but it gave off a lot of fumes when it was first lit so I had to light it outdoors and let it burn for awhile before bringing it into the tent. That made for some uncomfortable mornings since I had to jump out of bed and walk around the cold tent for awhile, dealing with the kerosene heater. And kerosene gives off a lot of fumes, which never really bothered me but seemed to bother some of my friends.

So this year, I replaced my kerosene heater with a propane tank-top heater. I use a Mr. Heater MH15T tank-top heater. It attaches directly to a 20 lbs propane tank and gives off about 15K BTUs. That's a bit less the the 22K BTUs I got from the kerosene heater but it should still do the job. I used a BTU calculator to figure the difference. For a 12' x 14' "poorly insulated room", 15K BTUs will raise the temperature about 30 degrees (compared to 45 degrees for 22K BTUs). That will get me into December, when the temperatures drop down to the 30s and I can finally install the wood stove.

Mr. Heater MH15T tank-top propane heater

A few nights ago, I lit the propane heater for the first time. I brought a new, full propane tank into the tent and attached the heater. Propane tanks have left-hand threads so I struggled a bit getting the heater attached. I'd screw in the connector a few turns, but then it would start to feel like it was cross-threading so I'd take it out and try again. When I finally did get it connected, it still didn't seem quite right, but I thought, "Well, I guess that's just how it connects" (Mistake #1).

It was late in the evening and the temperatures were dropping quickly so I was anxious to fire up the new heater and get things nice and cozy! I opened the tank valve, opened the heater valve, and placed a lighter in front of the heating element. I lit the lighter first, then pushed the safety plunger in to let the gas flow. That's really important because propane is very flammable, so you should always have the ignition flame lit first before turning on the gas! Otherwise, gas can accumulate while you're struggling to light the match or lighter and...Whoof!

As soon as I pushed the safety plunger, gas began to flow to the element and, with my lighter in place, the element lit right up! Nice! I held the plunger in for a few more seconds while the thermal coupler came up to temperature, then let go. Done! A lovely orange glow spread across the element as it hit its stride and began warming up the tent. "Oh, nice", I thought, "this is gonna be great! Propane is so much easier and quicker and cleaner than kerosene."

(And so much more volatile!)

I sat back on my knees on the floor next to the heater and smiled, enjoying the warmth. And it was right about then that I smelled something. Gas. Hmm. Must be a bit of gas escaped from the element while I was lighting it (Mistake #2). Then I remembered the difficulty I had connecting the heater to the tank. Could there be a leak around the connection?

Okay, let's pause for a moment to talk about gas safety. Here's the procedure for checking for a gas leak:

• Step 1. Turn off the gas
• Step 2. Make sure you are in a well ventilated area
• Step 3. Make sure there are no open flames in the area
• Step 4. Pressurize the system (in my case, open the tank valve)
• Step 5. Wet down the suspected parts with a soap solution

Even the smallest of leaks will cause bubbles. Once you find the leak, turn off the gas, fix the leak, and repeat the process to be doubly sure that the leak is gone. Easy, right? And safe, too!

And what you never, ever, ever do is check for leaks using a lighter!


Now, back to the story...



"Hmm, maybe there is a leak around that connection", I thought. But I figured it would have to be a small one (Mistake #3). I still had my lighter in my hand, so I put it next to the connection (No! Mistake #4!) and lit it (oops...that was definitely a mistake!)

Poh...Whrroof!!!

I felt the pain first in my right hand, which was holding the lighter and took a direct hit from the fire ball. Then, I realized my bare feet had been burned, too, due to the large "puddle" of gas that had accumulated around the tank. And the pain continued up both legs to my knees, which is apparently how far the gas had travelled up my pant legs.

Fortunately, they were only first-degree burns, which was good because I didn't really have time to think about the pain. Instead, I had to deal with the propane tank which now had eight-inch flames shooting out around the heater connection. My first instincts were to quickly reach into the flames and shut off the main valve. I did that three or four time, getting in a half-turn on the valve each time I darted my hand in and out. After about the fourth attempt, I realized that I was getting some pretty good burns on the back of my right hand. I paused for a moment, thinking about how I could protect my hand, but then worrying about the flames dancing around the top of the tank, I reached in one more time for a quick turn of the valve. And on that turn, the flames finally reduced a bit. One more quick turn, and the valve was closed. I escaped with only minor burns.

Once the flames were out, I closed the valve good and tight and set the contraption outdoors for the night. The next day, I removed the heater from the tank and looked inside the tank valve. The rubberized o-ring that was normally in place around the check valve was completely missing. I suspected that the tank had been shipped that way. Without that o-ring, gas would have been streaming past the heater connection.

Yeah, I really love my new propane heater! So much nicer than kerosene!