Mr. Heater in a 2120 SC

[Jersey Jim]

Let us know how they work.......

Well I spent a couple of trips out with the Mr. Heater, so now have a good idea of performance. I did however, switch to the slightly smaller "Little Buddy" model of Mr. Heater. I it only puts out one heat level (3,800 Btuh) instead of the 4000/9000 of the "Portable Buddy" model that I only used on the low setting anyway. I get a little more time out of the smaller model ( 6 hours exactly) running continuously. I switched models because I like how the entire unit can be mounted/secured by it's 1-pound fuel bottle. Also, the smaller unit aims the heat upward at an angle, and does not heat the deck and side walls at all. Can be mounted much closer and heat rises straight up, as well as radiant heat. I plan to secure a 4-inch (inside diameter) pvc pipe, 5 inches tall, to drop the entire heater into, by it's bottle. I may use a large knurled knob tapped threads into the pvc in order to secure the heater down. I am also thinking of a large magnet in the bottom of the 4-inch sleeve to hold it and stop it from rotating.

Ok, now some performance results. The smaller heater runs 6 hours, and heats the cabin 30 degrees F increase over the outside temperature, even in strong winds. This is with the side windows cracked a quarter inch each for ventilation and CO dissipation. With no wind, you could get by cracking them a little wider.

Now for the CO test results... under worst case conditions, (boat inside my barn, no wind, and windows & doors closed up tight, 32F ambient) the heater ran steady 2 hours before CO climbed to a level of 46 parts per million. Temperature reached 61F inside. Audible alarm did not go off, as this is an acceptable level. According to OSHA, a worker can be allowed to breath a concentration of 80 ppm for an entire 8 hour shift (if I recall correctly). I'm not sure what level First Alert programmed their unit to sound off at, as I will have to test & verify that (probably 200 ppm I'm guessing).

Then I cracked both side windows 1/2-inch and within 20 minutes the level was down to 30 ppm and still dropping. There was no significant difference in reading from levels tested at the lower v-berth, opposed to on top of the helm. Maybe 1 or 2 ppm difference. I then opened the cabin door for 5 seconds and within a minute after closing it the monitor resumed reading temperature instead of CO. Upon scrolling through the displays, the level was at zero.

So these units are safer than I expected (or at least, burn more thoroughly than I expected). I still recommend a CO monitor, but if not gotten around to it, maybe these results will put your mind at ease until you can acquire one. I recommend one with a realtime display of the concentration. First Alert sells one for 50 bucks at Lowe's, and Kidde makes one too (I had years ago). Both are battery operated. The First Alert is disposable after 10 years, as it has a sealed 10-year lithium battery (non-replaceable).

 

[Jersey Jim]

There is also another screen (not shown) that shows the peak level achieved, even after condition clears back to a zero level.

 

[shawnee83]

What kind/brand of monitor is that Jim?

 

[Jersey Jim]

What kind/brand of monitor is that Jim?

That is a "First Alert" model CO710 sold at Lowe's for $49.95 I tried to attach the 5-page manual from the First Alert website, but the file size of the pdf was too big. Since when did 5 pages require 4.6 MB?


When I get a chance, I will see at what concentration of CO that the monitor will alarm. The blue backlight only comes on for a few seconds once pressing the button on top. Like I said, the sealed Lithium battery is to last 10 years and then you replace the unit. The cell wouldn't last beyond that either, even if the batteries were replaceable.

Also, the smaller heater I switched to doesn't illustrate this in the pic above, but there is a built-in plastic carry handle integrated into the plastic housing, in the rear behind the reflector.

BTW, did you see the wide roller I added to possibly protect the keel from the grating on my trailer?

 

[moose8420]

I've been using a buddy heater for the past couple of years now. I sometimes will use it in the middle of summer when its 45 and raining. I found that if I put it on the cabin deck below the door, it doesn't have a tendency to tip over. I've always been amazed that in a 2-4 chop, the heater will stay running. I have noticed that the slightest touch from a foot will engage the tip over switch. One bottle will get me from my cabin and back about 120 miles during the winter time.

 

[rwp48]

I have been using an aluminum cookie sheet as a portable heat shield. I know it wouldn't be effective if I had a runaway fire but it seems to work fine deflecting heat and keeping surfaces near the heater cool. Of course, I haven't needed it this winter. It was 82 degrees today, here on the east coast of FL.
Sorry...I just couldn't help myself!

 

[shawnee83]

Thanks Jim for the info Jim. I did see that roller you added. Looks good. That should definitely cover any chance of hitting on the wa on the rollers. Nice work on that.

 

[Jersey Jim]

....... I found that if I put it on the cabin deck below the door, it doesn't have a tendency to tip over.....

Do you find you get the same 25-30 degree temperature rise inside? I suppose it would be even more effective if you drew the curtain closed and sealed off the v-berth area while under way.
Also, how much do you crack your windows to prevent any glass fogging due to the combustion?

It sounds like you place your heater in the most stable location... most aft as possible, & centered. I don't feel comfortable unless I anchor my heater down. The small tank-top mounted model uses the same tip-over mercury switch as the larger models, and work exactly the same way. I never have any shut-offs any longer due to wave action.

 

[Jersey Jim]

I have been using an aluminum cookie sheet as a portable heat shield....

Great idea! I initially was toying with aluminum sheet stock from Lowe's. The cookie sheet has raised edges that forms an insulating air gap... I like it.

 

[Jersey Jim]

Dangerous CO Levels over time

 

[Jersey Jim]

I finally got around to making a new mount for the smaller style Mr. Heater. I like how the heat does not heat the deck and nearby side objects like the squareish model I was originally using (see pic on 1st page). I feel this model is much safer for the cramped quarters in a 2120. There is truly nothing nearby that gets heated due to close proximity of the heater. This is the best location I came up with that is out of the way of people coming and going. Just turn it on when leaving the dock, and let it run the entire time, or until 6 hours, whichever comes first. I also like how you can secure it down by it's bottle, as the entire heater spins onto the top of the bottle.

I used a piece of 4" pvc pipe and a 4-1/8" hole saw to make a 1-1/2" thick plug for the bottom of the pipe. This wooden base is secured b 4 screws, 90-degrees apart. The 1-lb. camping bottle of propane fits like a glove inside the pvc sleeve like it was made for it, with maybe 1/16" to spare. I tapped 2 holes in the pvc (5/16") and used 2 knobs to secure the heater down. by it's bottle. This is more for preventing it from rotating in the mounting sleeve, and aiming in the wrong direction. One #14 screw through the center of the wooden base is all that I drilled into the deck. It is rock solid secure.

Like I mentioned in a prior post, this heater is 3800 Btuh, and lasts 6 hours exactly on continuous output. It will heat the cabin 30 degrees warmer than the outside temperature, even in wind. I only wish I considered this model prior to buying and modifying the first one.

 

[shawnee83]

Looks good Jim. Great idea