By Russ and Tiña De Maris
While our own four-footed feline thinks our “cat” heater was made just for her, “cat” stands for catalytic. These flameless heaters are the “cat’s meow” for producing lots of heat with little or no electrical power consumption. They use a specially coated catalyst “bed” or mat to efficiently burn propane. They are flameless after lighting — they do produce a bit of a flare when first being started — as our own cat was rue to find out. She stuck her face right up to the heater and it flared, giving her a close shave and the loss of a few whiskers. She learned quickly and now stays back several inches anytime we’re lighting the thing up.
Catalytic heaters are highly efficient: 95 percent or more of your propane fuel is turned into heat, all of it released inside the rig. Most are small and can mount directly on a wall, as they have very small clearance areas required. They can also be put on legs (cat feet?) and pointed wherever heat is needed. Since they are radiant heaters, they will quickly warm up any object or person in front of them, but they do take time to heat up the house. This is because the radiant heat of a cat heater has to be absorbed by something (or someone) and then gradually released. Think in terms of walls and floors. However, they are practical for heating your rig.
Catalytic heaters do have their drawbacks. Since they are non-vented, meaning that they don’t release anything to the outside of the rig, they will add moisture to your RV air. If you’re in an area of high humidity, a cat heater will add to the dampness. They also draw their air for combustion from inside your rig. The catalytic process requires less oxygen than an open flame, but it is a consideration. It is best to crack a window whenever you run a cat heater, so that the air that is used can be replaced.
The heart and soul of a catalytic heater is its catalytic “bed” or mat. This specially impregnated material is where all the heating takes place. The bed is susceptible to pollutants, so if you frequent areas where air pollution is rampant, the bed won’t last as long as it might otherwise. Contaminants from propane or propane containers can also migrate their way up the propane lines into the catalytic heater, contaminating the bed. Our own catalytic heater has had to be sent in for service when gunk from the propane lines clogged some fine orifices, reducing the heat output significantly.
What’s to be done? Olympian, the maker of a large number of catalytic heaters, has several recommendations. When not in use, catalytic heaters should be kept covered. You can buy specially designed covers from your catalytic heater manufacturer. This tends to keep the airborne pollutants off the cat bed. As far as fuel-borne contaminants, avoid using LP produced in Mexico. The company says this fuel often contains contaminants that can clog orifices and damage catalytic beds.
Olympian suggests propane cylinders be “purged” once a year to remove tank contaminants. This is an operation best performed by an LP dealer. It’s not an expensive operation— and with catalytic beds costing in excess of $100 (not to mention labor charges), it’s cheap insurance.
Cat heaters are rated based on their heat output, measured in BTUs (there they are again, those British Thermal Units!). The greater the BTU output, the higher the cost — but, of course, the larger the area that can be heated.
Most cat heaters use no electricity. This is great for solar and wind power users — stay warm while keeping the batteries for other uses. However, these no-power cats have a drawback: They have no thermostat. Generally, you’ll have a choice of high, medium or low output; but if they’re on, they’re always heating. There are thermostat-equipped cat heaters that do use a small amount of power to control heat output to keep things more comfortable if the inside temperature fluctuates. Still, we’ve learned how to put up with the lack of thermostatic control and can usually tell at bedtime at just what setting to leave our cat heater.
(Editor: Here is a link to catalytic heaters at Amazon, including Olympian.)