By Greg Illes
Heating in most RVs is with a forced-air, propane-fired system. These heaters are effective at heating up the trailer or coach in short order but they have disadvantages. A forced-air heater is noisy and it uses a 12-volt driven fan to circulate air. If you’re not on shore power, a long cold day could deplete your battery.
An alternative is the propane ceramic (radiant) heater, which uses no fan. It’s a real boon when boondocking (pun intended) not to drain the battery, and the quiet heat is very pleasant. Most coaches don’t have built-in radiant heaters, but you can easily add one. Models are available in many sizes and prices. Small portables start at around $50, and the larger units run $150 and up.
These add-on heaters can be supplied from a small propane bottle, a bulk-style bottle, or plumbed into your propane system. (Propane in small bottles costs 20 times that of bulk, not cost efficient to use for high-consumption heaters.)
The amount of heat to keep your coach warm is less than what’s needed to quickly warm it. A forced-air unit takes 20 minutes to warm a 30-foot motorhome. If you use your forced-air heater just to warm things up, and then the radiant to keep it warm, you are win-win. You get warm quickly and then eliminate noise and battery drain. This way, a radiant can be sized at much lower capacity. Even a 6,000 BTU/hr unit can keep a 30-foot coach warm in most climates.
Some caveats for using the ceramic heaters:
•They all burn propane inside your coach and are not self-vented (like your forced-air unit). You MUST provide ventilation — a slightly-open window (1″ or so) usually does it.
•Be sure to purchase a unit with a thermal control. This will allow it to self-cycle on and off as needed.
•All units must have low-oxygen sensors (and your coach should have a CO monitor). But some people are still not comfortable leaving a radiant heater on while they sleep (I’m one of them).
•For fire-risk reasons, most people won’t leave the radiant heater on while they’re not in the coach.
•Despite these operational limitations, the radiant is a valuable tool for managing RV heating.
Editor’s note: Many authorities view having a “bulk-style” LP cylinder inside an RV a major safety hazard. A properly plumbed gas line to the RV’s low-pressure side is much safer.
Greg Illes is a retired systems engineer who loves thinking up RV upgrades and modifications. When he’s not working on his motorhome, he’s traveling in it. You can follow his blog at www.divver-city.com/blog.