RV Repair Manual
for the RV Do-It-Yourselfer
A catalytic heater burns propane in an efficient manner (almost 100% according to some manufacturers) and uses little or no 12 volt power. It sounds great for RV use ... but is it?
Ideal propane combustion in a catalytic heater produces only heat, water vapor and carbon dioxide. It also uses oxygen from the immediate environment and exhausts the products of combustion into that environment. So, therefore, the oxygen must be replaced and the water vapor and other products removed from the RV in some manner.
The catalytic heater manufacturers suggest that a window be left open or another source of fresh air is provided. Hmmm ... what if the 5 year old gets up in the night and closes that window?
Less than ideal combustion produces carbon monoxide. Carbon monoxide is a killer gas ... odorless, colorless and invisible.
RV furnaces are designed to use a vent system - outside air is drawn in to the combustion chamber to supply the flame with oxygen and combustion byproducts are exhausted to the outside. Water vapor produced by the flame is also vented outside. While RV furnaces are notoriously inefficient in fuel and electrical power use, they do the job reasonably well.
Many people swear by the use of their "cat" heater, and many others warn of the associated dangers.
A new type of vented catalytic heater is presented by the website listed immediately below ... this is not an endorsement of the product and is presented for your information only.
"THE PLATINUM CAT utilizes a power vent system which exhausts all combustion by-products to the outside of the living area, which automatically replace oxygen used for combustion. The vent system prevents buildup of unhealthy indoor air pollution and eliminates any chance of accidental asphyxiation."
I must replace the heat source in my 30ft fifth-wheel. I have heard the low pressure LP gas Catalytic heaters are much more efficient than the forced air furnace and they don't require a battery. Most of the advertisements say this model or that model is designed for RV's, but the last sentence says they do not meet the ANSI A119.2 standards for RV's. Are they safe, and how much ventilation do they need? Any advice and experiences would be greatly appreciated.
Some folks use 'em, some don't.
Les is admanently against the use of catalytic heaters in RVs and, in fact, in some places in Canada they are illegal.
The bottom line is that, when using any air/fuel burning device in an RV, sufficient ventilation must be provided to replace that which is used up and to allow for the release of the deadly gaseous byproducts that are produced. What is "sufficient" ventilation? I guess that would depend on the device and the mfgs recommendation.
Personally, I find it distasteful when a company recommends their catalytic heater for an RV and then adds the ANSI disclaimer to protect themselves when/if someone dies as a result of using one.
Mike, well said.
Any combustion process has to vented outside or it will build up CO levels in the RV. I'd never use this type of heat as the only source in an RV.
Thanks Mike & Ken I appreciate your input. I dry camp at wildlife management areas and I am concerned about the battery life with a forced air furnace.
This board never ceases to amaze me, this much knowledge and experience in one place.
Thanks Again Everyone
What about heating the RV in the winter when nobody is actually occupying. My 36' MH is right next to my house and I like to keep it at above 40 when not in use. I do monitor it daily. I now use a Polonis ceramic heater but at full throttle it draws 13 amps. That drives the electric bill up significantly.
This thread was far too brief. I'd hoped for much more. I have read posts elsewhere that Catalytic Heaters don't actually "burn", they induce a heat-producing catalytic reaction, and thus, don't produce Carbon Monoxide. They do, however, consume Oxygen. I haven't done enough product research yet to know about others, but the Olympic brand has models with O.D.S. (Oxygen Depletion Sensor) that shuts the heater down if room air Oxygen gets too depleted. I live in California and noticed one product could not be shipped to Calif. Can't remember if it was a Catalytic, Ceramic, Radiant, Blue-flame, or whatever. I'm wondering if that applies to all Non-Vented heaters or what. I'm preparing to begin boondock/dry-camp life and zero-electricity appliances would make sense for me. On that subject, what do you-all think of those Propane Lamp-Fixture-Mantle-Lights.
Thanks, this truly is an exemplary BB/Forum.
I have looked a little at catalytic heaters. Are there any that use "bulk" propane and not the small, expensive bottles? Like a gas line to your propane tank? We use a 1500 watt heater and would not think a catalytic heater less than about 5000 btu would be worth it. ymmv.
Not too long ago a couple of kids my daughter grew up with went hunting in the winter. As was their custom, the used a catalytic heater in the tent and very diligently opened a window flap to ensure adequate air exchange. Unfortunately sometime during the night the flap became untied (possibly because of wind) and closed. The boys never woke up.
Sometimes taking a chance just isn't worth it especially when the heater is used only for comfort, not for survival. Even using such a heater to warm up an unused unit can use up the oxygen and upon entry the worst can happen if you aren't aware of the danger.
Wow Karen, that's quite an eye-opening story.
Do you know if it was due to Oxygen Depletion vs. Carbon Monoxide Poisoning? Also, I just noticed that I typed the name of the company wrong. It's Olympian, not Olympic. They make several Models in different Product Lines. The ones with ODS Oxygen Depletion Sensor have outputs from about 5000 to 10000 BTU and are plumbed to the low-pressure LP lines in your RV. Typically by installing a Tee fitting into a line to fridge, stove, or water-heater. Can also be portable by attaching optional legs and flexible hose, even a quick-disconnect coupler to store it away when not in use. And yes, with a regulator equipped hose can be connected to bulk tank.
Definitely lots of good and bad points, many more than have been addressed in this thread. I could go on and on with what I've read about them, but ...
Just last week our local newspaper (in the Beale AFB area) reported that two soldiers had recently died in their tent one night while on maneuvers. Although autopsies had yet to be performed, the catalytic heater the two men had used to heat their tent was thought to have created the conditions that caused their deaths.
I remember using the little coleman catalytic (back in the 70's) while camping in my friends van. We used to wake up with a terrible headache even when we didn't drink.....I'd stay away from anything that sounds like catalytic.
For those of us that receive the C/W Prez Club magazine RV View and might be interested in the Mr. Heater reviewed on pg 33 please take note that the portable propane heater is advertised as CSA certified safe for indoor use. If you will go to Mr. Heaters home page you will find that it is approved by CSA International, (Formerly the American Gas Association),Not the Canadian Standards Association as the ad seems to indicate.
AyJay in MA
I have used a 8,000 BTU Olympian (same one) in my last two motorhomes. I love it, but would never leave it on when I go to bed. The instructions say leave a window open 1". That will generate enough fresh air. I would never use this type of heater in a space as small as a tent. However, in my 34' MH it is perfect, but I use a down comforter when I go to bed and turn off the heater.
Use um if you want, but please be very cautious, I worked with four people that died from oxygen depletion. I've read a square inch for every 1,000 BTU. Don't know that I've enough guts to sleep with one running. I'm gonna die in my sleep soon enough, don't need to rush it any.
Recently, I helped with a refurb on whats called a honeywagon. This is not to be confused with a honeybucket. A honeywagon is a multicompartmented trailer used by showbiz types to hang out and dress in.
Each room of the wagon had a catalytic heater in it as original equipment. But, each heater was removed and tossed in the junkpile as part of the upgrade. This was usually accompanied by the new owner's murmurings of how deadly they could be. They were replaced with small ceramic heaters that were more than sufficient to make the room toasty warm. He thought it better to spin the meter or load the genset than to have a very sick or dead person on board.
A bit of the science associated with using a catalytic heater in an enclosed area is this: Carbon monoxide (CO) is produced by the incomplete combustion of the fuel/air mixture. A particularly nasty action of the CO is to attach itself to the blood's hemoglobin and surround it. Thereby, it keeps the blood from abosorbing and moving oxygen around one's body. This isn't an action that's immediately reversed when the CO is removed from the ambient environment.
The other edge of this particularly nasty sword is that ANY burning of fuel requires oxygen. This is true from a blast furnace to a quiet little catalytic heater that just glows and gets warm. Therefore, as it burns it uses up oxygen from the air around it. So, not only is the catalytic heater producing CO that can reduce your body's ability to use oxygen, but it's in competition with you for what oxygen is available.
Catalytic heaters are fine when they are used in a truly well ventilated area. (This means that there is some constant input of fresh air.) They can make a lot of heat and I've warmed myself by one on many an occasion. So, they have their place. But, to intentionally seal one's self in a small area with a device that can asphyxiate and suffocate seems like just asking for some slow walkin' and sad singin' to me.
A previous writer brought up another good point. Even if you're using a catalytic heater just to keep your unit warm while unoccupied, the oxygen depletion goes on as well as the formation of CO. So, if you decide to step inside for some minor chore, (I just came in for a few things.)you could wind up exiting boots first. Be careful!
Don't forget any pets either. A dog/cat/bird/etc. won't last long if they're stuck inside an RV being heated with a CO generator and little/no fresh air coming in.
I want to thank everyone for spending their time to respond to this question. I think I'll go with the consensus and sidestep the dangers in favor of the normal factory furnace.
Thanks again everyone.