We froze in our trailer during the winter of 2007-08 in Arizona.  Morning temperatures in the

kitchen were often 47 degrees, and although daytime kitchen temps could get as high as 70

degrees (even 80 on those days we baked a chicken in the oven), as soon as evening

came, the temps dropped into the low 60's or high 50's.  Brrr!  It's hard to sit around in the

evening in those kinds of temperatures.  Most trailers (ours included) come equipped with a

propane furnace.  However, these loud, inefficient beasts use a lot of electricity, and can

drain the batteries in one night.

That first winter we discovered that the more experienced winter desert boondockers

installed vent-free propane heaters in their rigs.  These are wonderful little appliances that

use far less propane than a furnace and no electricity at all.  When we bought the Hitchhiker

fifth wheel in May, 2008, we decided we would install one.  All summer long we thought

about the project, but never found ourselves in a town where there was a good selection of

heaters to look at or anyone knowledgeable about installing them in RVs.  So we dawdled.

As the nights got colder in late November, 2008, and we relied more and more on our

trailer's electricity-eating furnace, we found ourselves in the warm company of our good

friends Bob and Donna Lea Jensen and their vent-free, electricity-free propane heater.  Bob

has installed quite a few of these little devils and he gave us some hints and loaned us two

critical tools for the project: a pipe cutter and a flaring tool.  We learned a lot through all this,

and I thought it might be helpful to others to include some notes here about our project.

PROPANE FURNACES

There are several types of vent-free heaters on the market, and each has its pros and cons.  In the end, we opted for a 20,000

BTU thermostatically controlled blue flame heater by Vanguard.  The night before the installation we laughed as we bundled

ourselves into our recliners wearing multiple layers, buried under blankets for the last time.  Mark's face peaked out from under his

hood as he read.  The night after the installation, in shorts and t-shirt, I had to poke my nose out the window for cool air; in our

excitement we had inadvertently heated the bedroom to 85 degrees.

Propane uses oxygen as it burns and gives off moisture as a by-product.  Therefore it has the potential to use up all the oxygen in

an enclosed space and kill any living, breathing occupants, and it also creates a lot of condensation on the insides of windows.  To

accommodate these unpleasant aspects of propane heating, traditional RV propane furnaces use a large blower system to bring

in outside, oxygen-rich air.  In turn, they vent the inside, oxygen-depleted air to the outside.  Circulating the air this way also

significantly reduces the build-up of condensation inside, as the moisture gets blown outside along with the exhausted air.

However, by blowing all this warm air outside, the furnace is effectively heating the outdoors.  If you stand outside an RV next to

the furnace vent on a really cold day, you can warm your hands and body quite nicely.  Also, this blower requires electricity to run.

RV furnaces are DC, so they do not require an inverter or generator in order to operate.  However, the amount of power they use

is astronomical (our 40,000 BTU furnace uses 11 amps DC).  You are then faced with a choice of either keeping the RV

unacceptably cold, or using a generator to keep the batteries charged (even our big solar setup on the Hitchhiker was not enough

to keep up with the furnace blower).

Besides heating the outside air and running the batteries down, a major disadvantage of a standard RV propane furnaces is that

the blower is really loud.  There is nothing like being deeply absorbed into a really great movie, and--right at the moment where

the most profound dialog is being exchanged in whispers--having the furnace suddenly roar to life and drown out everything being

said.  Our furnace blower often woke us up out of a sound sleep too.

VENT-FREE HEATERS

In contrast, vent-free heaters are silent and provide heat without using any battery power.  This is because they rely on you to give

them fresh air: you have to crack open a window while they run.  Most vent-free heaters are designed with an internal oxygen

sensor that shuts off the heater if the oxygen level in the room becomes too depleted.  In addition, most RVs come equipped with

an oxygen sensor and an LP detector that will sound alarms if the oxygen in the air drops too low or if an LP gas leak is detected.

You may also need (or choose) to run a small fan to circulate the air.  This will use some battery power, but you can decide how

much or how little to use the fan.

So, in essence, when using a vent-free heater, you must find a happy balance between several variables.  Determine which kind

of heater will best suit your needs (see descriptions below), where to place it in the RV, which window(s) to crack open, and how

often to run a fan (if at all), and if so, which kind of fan to use (a little DC fan, like one used in a computer, a large AC ceiling fan

that will require an inverter or generator to run, or an optional blower fan that can be purchased with the heater).  Heat rises, so in

fifth wheels the heat tends to gather in the bedroom.  Simply close the door to the bedroom, or crack it slightly open to control the

movement of the warm air into that space.  Likewise, if using a ceiling fan, you can experiment with running it forward or backward,

either to draw air up and move it out along the ceiling or to push the warm air down towards the floor.

Propane has a fixed capacity for providing heat.  One gallon of propane contains 92,000 BTUs of potential heat.  Our Lynx travel

trailer came with a 30,000 BTU furnace, and in our Hitchhiker fifth wheel came with a 40,000 BTU furnace.  Because of the

inefficiency of these furnaces, both burning propane and battery power, using the furnace alone for heat, we typically kept our

trailers at 55 degrees while sleeping at night and at 63 degrees in the mornings and evenings.  We used almost a gallon of

propane a day, could barely keep the batteries topped off using solar alone, and were quite uncomfortable.

After baking ourselves til golden brown on our first night with our new vent-free heater, we sorted out which windows to crack open

and where best to place the heater.  We now keep the buggy at 68 degrees at night and 76 degrees during the day, and we are

always comfortable.  We still use about a gallon of propane per day (but we are warm!) and we have no trouble keeping the

batteries charged using solar alone (except for during multi-day winter storms when we fire up the generator).

WHICH VENT-FREE HEATER?

When choosing a vent-free propane heater, there are a lot of products on the market.  Catalytic and ceramic heaters offer radiant

heat, heating objects situated nearby in the same way a fireplace or woodstove would.  The air in the room becomes warm over

time.  Blue flame heaters heat the air, providing a more even, uniform warmth.  Gradually, the objects in the room warm up as the

overall temperature of the air in the room rises.  All of these heaters come in different sizes, ranging from 5,000 to 30,000 BTUs,

good for heating 100 square feet up to 1,000 square feet.  Small ones can be hung on the wall, out of the way, while big ones that

appear modest-sized in the show room suddenly become monster heat sources that dominate the floor space when you get them

home to your RV.

CATALYTIC HEATERS

Catalytic heaters were the original vent-free heaters.  The major manufacturer is Olympian, and their primary models are the

Wave 4, Wave 6 and Wave 8 heaters.  These provide 4,000, 6,000 and 8,000 BTUs of heat respectively.

Catalytic heaters provide radiant heat, meaning that they heat the objects sitting near them first, while the air warms up in the rest

of the room as time progresses.  This is akin to a fireplace or wood stove.  There is a large pad on the surface of the heater, and

the heat radiates off the entire pad.  If you stand in front of it you will feel heat from your toes up to your knees or mid-thigh

(depending on the height of the unit).  If you sit close to the heater you will bake, a good feeling when you are chilled, but not

necessarily a great feeling a few hours later when you have warmed up.

These heaters have been in use for years, and have an enthusiastic following.  They are also quite expensive ($300-$430), often

as much as double the cost per BTU as the other types of vent-free heaters.  They do not have thermostats, so you must

manually turn them on and off to regulate the temperature in the RV.

If the pad on these heaters becomes dirty, it is possible to replace it for about $100.  A friend of ours tried to clean his by

vacuuming it, and ended up destroying the pad inadvertently.  Because the pads had changed slightly since he bought his unit five

years earlier, he could not replace the pad and had to replace the entire heater instead.

CERAMIC (BRICK) HEATERS

Ceramic heaters are a slightly newer technology that has been warming RVs for quite a few years.  Some common brands are

Vanguard / Glo-Warm (from the same manufacturer in Kentucky) and Kozy World / Pro-Com (from Japan).  These are generally

offered in one, two, three and five brick configurations providing 5,000, 10,000, 15,000 and 25,000 BTUs of heat.

Ceramic heaters provide radiant heat, like the catalytics.  There is one (or more) small ceramic "brick(s)" that heats up to a

glowing orange/red color.  Like a catalytic heater, standing in front of a brick heater will toast your toes to your thighs on the front

of your legs.  The heat from the bricks actually interacts with your skin and you will feel a special tingly warmth.

These are extremely popular units and can be quite inexpensive ($130-$350), and most can be purchased with or without a

thermostat.  One big disadvantage is that the area directly in front of the bricks gets hot enough to burn things.  Any flammable

items that come too close to the bricks will catch fire.  If a cat or dog wanders past and flicks its tail against the bricks, it will get

singed.  If a toddler sticks its fingers in there, a trip to the hospital might ensue.

BLUE FLAME

Blue flame heaters are the newest technology and provide a different kind of heat than the catalytic and ceramic heaters.  Rather

than radiating heat and warming up nearby objects, blue flame heaters warm the surrounding air.  Once the air temperature has

risen sufficiently, the objects warm up as well.  If you keep your RV at a warm temperature all the time (especially overnight), the

objects in the room will never get cold.

If you stand in front of a blue flame heater, you will feel heat from your knees up, and you won't feel heat on your toes or shins.

The heaters draw air in from floor level, heat it up, and emit the warm air out of vents at the top.  The area in front of the blue

flame is covered by fireproof glass and is relatively cool.  The heat warming your knees and torso is very warm, so you can have

that nice effect of warming your hands and body right in front of the heater after coming in from outside.  However, there is no risk

of items immediately in front of the heater catching fire.  Blue flame heaters are definitely a better choice for people with pets or

children.

Some common brands are Vanguard / Glo-Warm (from Kentucky) and Kozy World / Pro-Com (from Japan), the same makers of

the brick heaters.  These manufacturers produce both blue flame and brick heaters in the same chassis, so other than the

appearance of the bricks or the flame, the unit itself has the same look whether it is the brick or blue flame version.  The typical

BTU range on these heaters is 5,000, 10,000, 20,000 and 30,000, slightly higher in the larger units than the corresponding brick

heaters in the same chassis.

Blue flame heaters are as popular as the brick heaters, and are in the same price range of about $130-$350.  They can also be

purchased with or without a thermostat.

BLUE FLAME FIREPLACES

There are some wonderful blue flame heaters that are designed to look like fireplaces, complete with logs, trim and beautiful

wooden mantels.  Manufacturers include Vanguard, Buck and Martin.  These cost about $200-$300 more than the regular blue

flame heaters, but what a beautiful addition to your RV.  You can sit and watch the yellow flames dancing around the logs and

warm your bones at the same time.  I saw one of those units in an old travel trailer and was enchanted.  The owner had built his

own mantel out of an old coffee table, and it was lovely.  I wanted one of those units so badly!!

The only place for a unit like that in our rig was along the backside of the "L" in the kitchen counter, which is just a few inches from

the wall of the entertainment slideout when it comes in.  If we had the carpentry skills, we probably could have slipped a fireplace

in there, deeply recessed under the counter.  The only downside would have been that it might have gotten a little hot under the

counter, and we would have had to be extra careful that the heater was fully cooled whenever we brought the slideout in, or we

would have cooked the gelcoat on the outer wall of the slide.  Also, as it turned out, that particular location for the heater would not

have provided the same warmth when we sat in the recliners as the heater does in its current spot in the kitchen in front of the

oven (even though it would have been closer to them).  It's just the way the air flow circulates in our particular trailer.

OPTIONS

Thermostat

Usually this option is just $30-$50, and it is well worth the cost if you plan to be in your RV for extended periods of time.  A

manually controlled heater will have several heat settings (usually three), but you will need to monitor the heat in the room and

adjust the settings as you get warmer or cooler.  A thermostatically controlled heater will cycle on and off as its sensor detects

changes in temperature.  Ours typically cycles on and off in 5-10 minute increments, keeping the temperature within 2 degrees.

On our unit, the thermostat has a simple analog dial that can spin from "1" to "5."  These are arbitrary numbers rather than fixed

fahrenheit degree markers.  However, once you figure out how "1 1/4" or "2 1/2" relates to temperature, you can keep the

temperature in the room tightly controlled by turning the dial to the setting you want.  This is especially nice if you plan to keep the

heater on all night, as the temperature in the RV will remain constant while the outside temperature drops.

Feet

Most units are designed to be hung on a wall, however most also have an optional stand so they can be placed on the floor.  Most

smaller units include the feet as an option (about $25) while most larger units come with the feet at no extra charge.  The great

advantage to hanging a unit on the wall is that it is always there, ready for use.  If you use your RV during many different seasons,

it is nice to know that if you suddenly find yourself in a chilly spot, you can simply flip the switch and have your heater working for

you, rather than digging it out of the back of the closet.

The advantage to having the unit standing on its own two feet is that you can move it around the rig.  This is especially true if you

don't use a fan of some kind to move the warm air around the rig.  If you go this route, make sure you have plenty of gas hose so

you get maximum range on where to place the heater.

Blowers

Most units can be purchased with an optional blower.  As soon as you start blowing the air around the RV, you are signing up to

use the batteries to keep the rig warm, something the vent-free solution was aiming to avoid.  However, the power consumption

should be less overall than a furnace.  Some blowers are thermostatically controlled, allowing them to cycle on and off as needed.

This is efficient, as the blower and batteries won't be in use all the time the heater is on.  Rather than a built-in blower, many

people opt to install a small DC fan which uses very little power.  If your rig has a ceiling fan, that can also be an option, although it

will require the inverter or generator to be turned on.

HEATER PLACEMENT

When we installed our heater we tried placing it in several locations and turning on and turning off the ceiling fan, and running the

fan both forwards and backwards (blowing towards the floor and towards the ceiling) before we settled on a final arrangement.

We found that the best setup was to place the heater directly below our ceiling fan (in front of the oven at the base of the stairs in

the kitchen) and set the fan to blow towards the ceiling, drawing the warm air up and distributing it outwards throughout the RV.  It

was astonishing to find what a difference it made as we moved the heater to various places in the trailer and tried each placement

with or without the ceiling fan, and blowing up versus blowing down.

We have a "rear lounge" fifth wheel, and we found that the area around the recliners was a significant cold pocket.  Doesn't it

figure!  That's where we like to be on cold evenings!!  There are large windows surrounding the recliners, and as we sat there we

felt cold while we found the warm air congregated high up on the ceiling just in front of the stairs leading to the bedroom (that is, if

the bedroom door was closed.  Otherwise the warm air settled in the bedroom itself).  We assumed that facing the heater towards

the recliners just 5' in front of them would result in warming this cold pocket.  Wrong!  No matter how high we set the thermostat,

and no matter what we did with the ceiling fan (which is located just in front of the stairs leading to the bedroom), the recliners

were still cold.

When we moved the heater about 12' from the recliners, at the base of the stairs leading to the bedroom, and turned on the

ceiling fan to "high" and set it to blow towards the ceiling, we could immediately feel the warm air encircling us as we sat in the

recliners.  Who woulda thunk??!!

OPERATION AT ELEVATION

Most of these heaters are sold with an official limit as to how high they will operate correctly.  The problem at higher altitudes is

that the pilot light keeps going out because there is not enough oxygen for the propane to burn properly.  Some units have a limit

of only 3,500 feet, while other manufacturers have a stated limit of 5,000 feet.  Friends of ours use an Olympian Wave heater at

8,000 feet all summer long.  We have heard of people using the blue flame and brick heaters as high as 6,000 feet.  We have not

taken ours to higher altitudes yet.  **See note at the bottom of this page: we used it daily for six weeks at 6,000 feet and it worked

great.**

SIZE

Most units will state the square footage they are designed to heat.  We decided that we'd rather buy a slightly larger unit and

simply turn the heat down than to find ourselves unable to heat the buggy adequately.  Our rig is 360 square feet, which put us

somewhere between 10,000 and 20,000 BTUs.  We ended up buying a 20,000 BTU heater and typically keep it set to 50% of

maximum during the evenings/mornings and 25% of maximum at night.  If we had purchased a 10,000 BTU unit instead, I think it

would have been cranking at max volume most of the time during the mornings and evenings and on stormy days.  As a rough

guide:

BTUs

Square Footage

6,000

Up to 200 sf

10,000

Up to 300 sf

20,000

Up to 700 sf

30,000

Up to 1,000 sf

There are legal ratings for the sizes of vent-free heaters and the rooms they can be operated in.  Less than 6,000 BTUs is okay

for a bathroom, and less than 10,000 BTUs is okay for a bedroom.  These are the ratings that are being referenced when you see

a sticker on a larger unit saying "not designed to be used in a bedroom."  The idea is that a large unit, operated at max volume in

too small a space, will use up too much oxygen in the room too quickly.  Of course, such a scenario would have the occupants of

the room running out the door because it would be way too hot for comfort.

WHERE TO BUY?

We had the worst time trying to find places to look at these heaters and people knowledgeable about installing and using them in

RVs.  In some states it is illegal to sell these kinds of heaters, and in mountain towns they are scarce because of their issues

operating at high altitudes.  In four months we found just two propane gas companies selling vent-free heaters, one in Jackson,

MS and one in Kanab, UT.  We ended up learning the most from fellow desert boondockers in Arizona, Nevada and California

during the winter months and from salespeople in mom-and-pop hardware and RV parts stores in Yuma and Quartzsite, Arizona.

If you know what you want, you can get a much better deal buying online.  We paid $290 plus $25 tax for our heater, a Vanguard

20,000 BTU blue flame with a thermostat and no blower (it came with feet).  We found the same unit online with free shipping and

no sales tax for $175.  Ace Hardware could order a similar unit for us, shipped to their store in a week, for $215.  Most online

vendors claim it takes 2-3 weeks to ship, and we dawdled too long to go that route.  The worst of winter would have been gone by

the time we received our heater.  So we paid a premium for our unit, but we did talk to a lot of sales people in the process and we

saw a lot of the units (and warmed our hands over them), and knew exactly what we were buying.

COST

Our entire project cost $385. The heater was $315 (with tax), and parts totaled $70.  We were able to borrow the tools, but found

they cost only about $10 at the hardware store.  We were quoted between $60 and $100 for the labor for the installation.  We also

could have saved about $140 on the heater if we had purchased it mail-order.

INSTALLATION

Following is a pictorial guide through our installation.  Before installing the heater, there were three preliminary steps:

- Attach the copper elbow fitting at the base of the heater.  A gas hose would eventually connect to this elbow fitting.

- Attach the plastic feet so the unit could be freestanding and be moved around the trailer easily.

- Attach the thermometer for the internal thermostat.  This went on the lower back corner of the heater..

Tapping into the gas pipe

We decided to tap into the copper gas pipe that runs between the refrigerator and the stove at the back of one of our lower kitchen

cabinets.  Mark measured the pipe and found it was 3/8".  The goal was to cut the existing pipe and insert a series of fittings that

would allow us to attach a flexible gas hose at that point.  This hose would then run out through a hole drilled at the base of the

cabinet and attach to the heater.  All of this is low-pressure pipe and fixtures.

At the hardware store we picked up a T-connector that would be inserted into the cut copper pipe.  The

base of the T would connect to a female-female gender changing connector, and then to an on-off

valve (which has male fittings at either end), and finally to a female connector on the end of the flexible

gas hose.  Most of the year the heater would not be in use, so we bought an end-connector for the end

of the hose that goes to the heater.  When the heater is disconnected, this end-connector would be

screwed into the end of the hose and the heater would be put in a closet.

The first step was to cut the pipe.  This

requires a pipe-cutter, a small,

inexpensive tool.

The next step was to connect the T-connector between the two

severed ends of the copper pipe.  This would be done by sliding a

female connector onto the pipe end and then flaring the end of the

pipe so the connector couldn't slide back off again.  Then the male-

male T-connector would be screwed into this (and its companion)

female fitting on either end of the pipe, rejoining the pipe and

making a new connection available for the gas hose to go out to the heater.

The slight flaring of the end of the copper pipe

is accomplished with a flaring tool.

Mark practiced the flaring technique on a scrap

piece of copper pipe he got from the hardware

store first.  Inserting the pipe into the

appropriately sized hole in the tool, he screwed

down both ends of the tool, snugging the pipe

into the tool like the bad guys used to be fitted

into the stocks for punishment years ago.

Then he put the pointed end of the flaring tool into

the end of the pipe and twisted the crank, slowly

flaring out the end of the copper pipe as the point

pressed further into it.

He slid the female connector onto short piece of

pipe, feeling a snug fit between the pipe and the

connector.   The flare was just right.

Finishing the practice flare, he contorted himself to

get the flaring tool set up on the copper pipe at the

back of the cabinet.  Then he slid the female

connector onto one end of the severed pipe and

flared the pipe's end.

He did the same to the other piece of the severed

pipe, and finally screwed the T-connector into the

two ends of the pipe to rejoin them.  He tightened

the T-connector using two wrenches.

A female-female connector attached to the base of the T, making it possible to screw the male-male

valve into place.  This valve would allow the gas to the heater to be turned on and off.  After the valve,

he attached the female end of the gas hose.

Finally, he drilled a hole in the front base of the kitchen cabinet and ran the gas hose through the hole.

The other end of the gas hose was attached to the elbow connector he had placed on the bottom of the

heater.  Tightening all the connections with wrenches, and turning the gas to the trailer back on, the

heater was now ready to be used.  Mark checked for gas leaks using a tiny spritzer bottle filled with a

few drops of Dawn dish soap and water.  Spraying this mixture on each connection, he looked for

bubbles to form which would indicate a gas leak.

To give us flexibility in heater placement, we used

two lengths of gas hose:  a 3' length for under the cabinet and a 12' length that

attaches with an inline male-male connector to the 3' section that runs outside

the cabinet.  When we put the heater away in the spring, the 12' gas hose will

be disconnected and stored in a closet along with the heater.  Only the short 3'

section (with the stopper connector shown above) will need to be coiled up

under the kitchen cabinet.

After it was all done, it didn't seem like such a big project afterall, and what a

thrill it was to toast ourselves in our warm buggy.  Our timing was perfect: the

next week brought a big cold front, multiple days of rain, lows in the high 30's

and highs in the fifties.  We were snug as bugs in a rug while the winds howled

outside.

FOOTNOTE:  OPERATION AT ELEVATION

In the summer of 2009 we spent 6 weeks at 6,000 foot elevation in Ketchum/Sun Valley and Stanley, Idaho.  The mornings were

freezing!!  We woke up daily to outdoor temperatures in the low 30's to low 40's (33 degrees one morning, can you believe it?!).

We didn't run any heat overnight, so indoor temps were a miserable 48-52 degrees when we poked our toes out of bed.  We ran

the blue flame heater for 2-4 hours every morning and it worked like a charm.  It warmed us right up and kept us toasty until the

sun finally filled the trailer.  Of course, by late afternoon we were in shorts and tank tops with the doors and windows flung wide

open, the whole buggy baking in the sun.

There were several days when a nasty storm came through.  The skies were overcast and rainy and the outdoor temps struggled

to reach 60.  On those few days we ran the heater much of the day.  On one occasion, the oxygen sensor on the heater turned

the heater off.  The heater had been running for six hours that morning, and we had run it for a few hours the night before as well.

We also hadn't opened the doors or windows in over 24 hours at that point because it was so cold.

Other than that one time, the heater performed flawlessly and we were really glad we had it.  So, in our experience, a Blue Flame

heater rated by its manufacturer to operate at up to 3,500 feet of elevation can actually run just fine at 6,000 feet.