Adventure Location: Texas
The next modification to Comfort Castle has begun. First some background is needed. Additionally this may be a multipart coverage on an experiment of the change of philosophy for heating the rig. All of this is opinion as I have never seen any scientific analysis at all on the subject.
There are only three ways of heating most RVs.
A. Use open flame heaters or catalytic heaters
B. Use electric heaters
C. Use the onboard furnace
A common idea that the OFM followed for several years is that the onboard furnace wasted too much heat. All you had to do was feel the furnace to see that it seemed true. Wild unsubstantiated numbers like 30 to 50 percent loss come up in the forums. It eats too much electricity with the fan motor. It is too noisy.
Electric heaters are nearly 100 per cent efficient but you have to substantial 120 volt power to use them.
The myth is open flame or catalytic heaters use no electric and are nearly 100 percent efficient. However you lose serious heat due to the venting required. Thus they are not 100 per cent efficient in my book. How inefficent are they is not known by the OFM.
In the last four years the Castle has not used the broken onboard furnace. The stove top and its CO free burners have provided the little heat needed for when the Teams did not have 120 volt available. The Castle’s wheels kept the Teams close to 120 volt hookups most of the time in cold weather. That is planned to change in 2013. We are planning on more boondocking in dry cold weather.
In the last couple of years the OFM has noticed several folks mentioning that the open flame and catalytic units put out gases that caused them sinus irritation. The Teams have not had a trouble with that. With the extremely tight Arctic Fox trailer water vapor condensation from the open flame heating has been a major problem. As long as the outside temps were in the upper forties, it was manageable.
Keep in mind that the open flame heating style requires venting for oxygen as well as moisture elimination. The venting for oxygen requirement is rather small but still noticeable. However in the very recent trip to the desert in Big Bend NP it was noticed and agrees with some other folks experience in the better sealed RVs.
The temperatures were in the low thirties to low twenties for several nights. The gas burner had to run at nearly the 5000 BTU level of flame to keep the Castle warmed to 68 degrees. The result was a lot of water vapor running off the walls, windows and damp upholstery.
All that water vapor required massive venting. The desert humidity was running about 25%. I hate to think what that would be like at Rockport with the 70% humidity typical at night. The OFM noted that the back window in the bath now had to be open about three inches and the roof vent on the other end of the Castle had to be open about the same amount. If either was trimmed down within an hour things started to get wet again. Keep in mind the Castle is a little less than 150 square feet inside so a little water vapor makes a big difference in percentage.
Now when it is 25 degrees outside and you have a low window open three inches and a high vent open three inches to stay dry, your heating efficiency does not work out as really great. Another couple of folks that we correspond with on occasion have noticed the same thing on their rigs. At least one of them has gone back to running a small open flame heater and furnace heat to supplement while boondocking in the winter. They told me that with their well-insulated rig the furnace does not run their batts down very much over night. The solar panels get them back to full by noon most days. This is with outside temps in the twenties. The furnace does not cause added water vapor inside the RV unless it is cracked and then you have bigger trouble. MUCH BIGGER TROUBLE.
Another has told the OFM that all he ever runs is the onboard furnace and his solar keeps up just fine. He gets about a month between propane fill-ups.
With all this in mind, a repair person is scheduled to be here on Friday to get the Castle’s furnace running again after all this time. It will be a new era for the Teams to be boondocking in the colder areas during the winter. Tomorrow night the blog should be about the interior modifications being done to get the furnace back on line.
Pleasant comments will be welcome, flamers will be extinguished.
Keeping warm is very important when the task is trying to have tooooo much fun. TheOFM.