Desert Captain wrote:
Phil, yes Nexus really bumped up the furnace on our coach. Even at 35K BTU, it doesn't burn that much propane as it runs for relatively short intervals {about 5 minutes every 15 or so}. I attribute this to the overall energy efficiency of the coach. I love having the thermostat right next to our rear queen... very handy if you need to bump it up a few degrees in the wee pre-dawn hours. :B
The walls and ceilings are very well insulated, they use a large vacuum bonding machine utilizing Azdell, fiberglass, and foam. Once you get the coach warm, and it does not take long, it holds the heat {or cooler air from the AC in summer} very well. Another bonus is how quiet the interior is. A decent generator running in the next site goes unheard.
The rig came with DC tank heaters that I rarely use but with temps in the mid-thirties with the possibility of mid-twenties I turned them on more for exercise than out of any concerns of freezing. Another nice feature are the remote controlled heated mirrors.
We usually stay at the lower elevations during the colder months but temps down into the 20's are not all that rare during winter in the high Sonoran Desert as we enjoy our coach throughout the year.
:C
Thanks for the update! Are you in the middle of your cold outing now?
I don't know much about Azdell but in our Itasca, Winnebago seems to have also vacuum bonded solid white foam in between the outer fiberglass and whatever material the interior walls are. This foam appears to be nearly 3 inches thick under the roof's fiberglass and 2 inches thick in the walls.
Our furnace is only 25K BTU and of course is a nice over-kill in our 24 footer in the only 30+ degree weather we have so far camped in. LIke your furnace, it only runs around 5 minutes 2-3 times per hour with temps in the 30's. I'm not sure why all the complaints in the forums about an RV furnace sucking battery juice so much. 15 minutes of total run-time every hour is only around a 1.5-2.0 AH battery drain rate. I guess it's the interior volumes of our relatively small rigs that makes this furnace blower low average battery drain possible. Your 35K BTU furnace in only a 24 footer is very nice.
In cold weather we block off the cab from the coach with the snap-on cab curtain that Winne supplied ... plus we also cover the outside of the cab's windows with the common Class C white cover. In addition we use another cold weather Class C trick: Since the Ford cab air controls are vacuum actuated, before we turn off the engine when arriving at the campsite, we make sure that the cab air routing control is set to "OFF". This closes the door in the path that allows fresh air into the cab - which helps eliminate any random cold air sneaking into the cab when camped. I can definitely feel this slight cold air entering from the front cab area if I forget to do this.
I keep our roof vents open slightly in cold weather to maintain some fresh interior air and reduce interior moisture buildup. I don't feel any cold air coming in from the vents because a small amount of interior warm air is continuously escaping outwards through them instead, and because I have vent covers on the roof over them ... which acts to form a pocket of air insulation right above each vent lid. If we used those foam cold air vent covers that some cold weather campers mention, we could not maintain that very important slight air flow ventilation during cold weather camping. We've never used most of them, but I also pack along pre-cut air bubble blankets for each coach window ... just in case. The DW uses one in the window by her head in the rear corner bed and we keep one permanently installed in the forward facing cabover window.
I have rarely turned on our grey/black tank 12 volt tank heaters' switch when drycamping in the cold. I don't think I've ever been aware of them cycling ON, as I have a coach battery ammeter permanently mounted on the cab dash and can monitor the coach battery bank drain. I'm curious as to what current draw it will show whenever both of these tank heaters have cycled ON.
We have the Arctic Package option our our RV, so all interior fresh water system plumbing and components are kept warmed because they're within the under-cabinet coach open spaces right along with the warm furnace ducting pipes going to the various furnace outlets. All outside grey/black plumbing is up high next to the coach floor and their valves are contained within closed outside cabinets - hence not hanging below in the figid air when cold weather camping.
I'm curious as to what size your propane tank is? (Mine is only 18 gallons - equal to about 60 pounds of propane when filled to 80%. I wish Winnebago would have installed a larger one, as there's plenty of room down there for a larger one. :( )
Keep the reports coming. I always read your stuff ... cuz you often travel and camp in interesting ways and places! ;)