Oxygen sensor for catalytic heater

[Senorsedona]

Save the battery.

Again I say "use a Mr Heater when your boondocking" There is no battery draw & it will do a better job of keeping your TM warm.

Have fun...............
Jack

 

[BobRederick]

Bill & Lisa, VA

Thanks for the thoughts. You hit it on the head exactly. My best friend is gone but definitely not forgotten. I am now charting a new course through life without her help and friendship.

And Seniorsedona. I like your idea of the Mr Heater and it has been debated before. Although the efficiency is outstanding, one has condensation and oxygen usage to deal with.

Efficiency: It really bugs me to walk past the furnace outside and feel the immense amount of heat blowing out unused in the exhaust stream. It seems more than half the calories are dumped overboard. I don't think this is necessary, but maybe it is done to either a) make the furnace smaller or b) reduce condensation in the flue. Too bad. It leaves something to ponder.

Condensation: In Arizona, I would guess that normally, there is absolutely no condensation problem at all. So for all practical purposes, the furnace wouldn't be needed unless I want to quickly warm the TM up after coming "home". This would conserve battery, propane, and minimize condensation.

Oxygen: However, I do worry about the oxygen. Depleting that can be fatal and it would happen at night when I would not notice it. In my Coleman, I would notice getting 'light headed' if I ran the Coleman gas lantern and stood up. Apparently the CO concentrated near the cieling -- perhaps because of the heat of the lantern. A solution I am interested in is to install an oxygen sensor with alarm that could alert me to this condition. These are rather costly, require wiring, and one doesn't want it to fail or to be turned off or to have a depleted battery.... The solution I have heard for this is to leave a vent cracked somewhere. This can solve the oxygen problem, but it is quite subjective. Obviously, the TM is colder with the vent open and one will be wanting to minimize the size of the vent. One might also argue that the TM already has a lot of 'pneumonia holes' thru which ventilation air flows.

Has anyone experience with an Oxygen sensor to deal with this issue successfully?

 

[Bill]

Has anyone experience with an Oxygen sensor to deal with this issue successfully?

Actually, I combed the Internet looking for one and couldn't find one that would be useful. I did find a couple, but they were laboratory instruments, enormously expensive, required calibration frequently, and required a new sensor (very expensive) every couple months.

This is what concerns me about catalytic heaters that claim to have a built-in oxygen sensor. If it is a real oxygen sensor, I should be able to buy one somewhere. And if I can buy the whole cat heater for a couple hundred bucks, I should be able to buy the sensor for less than that. Instead, I see tens of thousands of dollars.

I don't know what kind of sensor the cat heaters have, but I am scared that it might be a simple temperature sensor. If the oxygen in the room gets severely depleted, the catalytic "flame" gets colder and just like a pilot light and thermocouple, the gas shuts off. But that is a pretty crude sensor, as all of us know who have fought with the same pilot light / thermocouple mechanism in the refrigerator or the oven. I'm not willing to bet my life on it. (Of course there is no flame per se in a cat heater - I'm referring to the temperature of the glowing conversion mat.)

Let me emphasize again that I don't know what the sensor in a cat heater is - the above is just my own speculation. I would welcome some actual information, but the cat heater web sites don't provide any.

Bill

 

[BobRederick]

Bill & all,

Is this the next best thing to an oxygen detector? If so, where is it mounted (floor or cieling)?

http://www.campingworld.com/browse/skus/index.cfm?skunum=15693

 

[ripp1202]

ODS stands for "Oxygen Depletion Sensor" , a term which accurately describes this valve type. The valve itself is similar in many ways to the two valve types above...with one exception. The pilot tube is a precision mechanism that creates a very stable flame as long as the room air contains the proper amount of oxygen. If the oxygen level in the room air drops even slightly, the pilot becomes unstable and lifts off of the thermocouple (see diagram) causing the gas valve and appliance to cease operation. This type of valve is very reliable, and there have been very few failures of this system - even with millions in use worldwide.

 

[Senorsedona]

Oxygen..

Using Mr Heater does use some oxgen, however the TM is far from air tight. There is more then enough air coming into the trailer to compensate for the oxyen burned off. A propane lantern will burn far more oxygen then the heater. I believe the rule is "one small window open 1/2 inch. But it is up to the users, what ever they're comfortable with.

Condensation: For some reason it has never been a major problem for me, I don't know why. I had a 5th wheel once & it was a major consern.

Have fun...........

Jack

 

[Bill]

Thanks, Ripp. That's more info than we've had in several discussions of this topic. I can imagine that this mechanism would be somewhat sensitive to altitude, which is probably why there is an altitude limit.

Jack, I'm sure you are right about a small vent and unintentional air leaks being enough. Just chicken, I guess.

Bill

 

[Bill]

Bill & all,

Is this the next best thing to an oxygen detector? If so, where is it mounted (floor or cieling)?

http://www.campingworld.com/browse/skus/index.cfm?skunum=15693

Probably not, Bob. A good cat heater doesn't produce much carbon monoxide. It burns propane to produce water and CO2 - and consumes oxygen in the process.

Bill

 

[pbuck1]

Bill & Bob et al,
How about one of these?

http://cgi.ebay.com/ws/eBayISAPI.dl...item=7598990573

and some more info:

http://www.generalmonitors.com/down.../TS420_DATA.PDF

Looks like it would need to hook to a current sensor/obnoxious noise generator - a small Radio Shack project, perhaps? (or maybe a modified smoke detector??)

Paul
__________________

 

[Bill]

Paul -

I couldn't make either link work, so I went around them. This looks like exactly what we are looking for, to use in conjunction with a catalytic heater. I have sent a question to the eBay seller regarding the units he is selling - I will report back. His price is certainly good.

Bill

 

[pbuck1]

Bill,
Sorry about the links and glad you found the info anyway. I've since read that 4-20mA loop-powered circuits are an instrumentation standard. Equipment for the monitor/alarm side should also therefore be available, but these seem to be custom to the measurement parameter itself, built for multiple inputs, of backplane/card construction for rack mount and probably expensive, etc.

The detector itself has a display will indicate a deficient O2 range (<19%) which is good, but no numbers and no alarm if you are interested in those. So , a Radio Shack project? What are your thoughts.

Look forward to hearing if you get one of these.

Paul

 

[Bill]

Oxygen sensor on eBay

I have sent a question to the eBay seller regarding the units he is selling - I will report back.

This particular oxygen monitor is shipped from the manufacturer in two pieces - the sensor head, and the sensor itself. The instructions say not to assemble the two until installation is complete. I don't know why - perhaps the sensor has a limited lifetime. Since the eBay seller describes his units as NEW, but NOT IN ORIGINAL PACKAGE, I emailed to ask him if he was shipping two pieces or just one. He told me on Tuesday that he was out of town until Thursday, and would check then and get back to me. It is now Sunday, and I have not received a reply from him. This being the case, I have to assume that his units are NOT new, but were removed from service, and have already been assembled. Once again, I don't know how much this matters, but it raises a big BEWARE flag in front of me. I was willing to buy one just to check it out ... but perhaps not, now that I see how the seller operates. I also note that his original auction has expired, and has now been re-listed.

Bill