I just bought a new Atwood 8535 34k btu furnace for my enclosed trailer and have a few questions. It doesn't come with a thermostat so what kind are you guys using. Will a regular house one work or does it need to be a 12v one. Also what kinda ducting material is everyone using. How much support do I need when I hang it from the wall. Also when I wire it into the trailer how big of fuse should I put on it. Also if anyone has any good info I haven't thought of I'd be glad to hear it. Read the whole thread on the old forum before I ordered which was very helpfull. Thanks for any help.
Trailer heater install question
- Thread starter w8ing4snow
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W
Wyoming T/A
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just a low voltage one will work. i have installed 3-30000 atwood-furnaces in the last 3 weeks. it only draws about 8 amps so a 20 amp fuse is plenty
how big of gauge wire they are using to run power to the heater
The gauge of wire required is proportional to the length the wire run will be. The installation instructions for the furnace reference some general wire run lengths and associated wire gauge. The two wires coming off the furnace fan are a 16 gauge wire. If the batteries are close, 16 gauge wire will be large enough. If the furnace is at one end of the trailer and the batteries at the other, you should bump up to a 12 gauge wire. Anything else at the relatively low amp draw would be overkill.
As for the thermostat it must be 12volt. They are very inexpensive. Consider where you mount it. I now install mine (3rd trailer with Atwood heat, and wiring friends now) by the man door. That way you can turn it on or off without climbing in the trailer. No need to go larger gauge than the two blue wires from the Atwood btw as this is simply closing a circuit, an no load is carried by these wires.
Personally, I use 4inch PVC pipe as its cheap, easy to work with, and secures well to the trailer. I've found drilling the pipe directly into the vertical rails that the interior trim is screwed to works quite well. There is a number of ways that this can be done. Also, the pipes will get hot, so keeping that in mind, personally I now mount them closer to the floor so the radiant heat off them warms the floor and not the roof. Load a sled, and make sure your placement wont be a problem.
Finally, I trust your going with 2 six volt batteries wired in series, and not 12 volt batteries. You'll be much better off.
Have fun, your trailer will be POPULAR when its cold!
As for the thermostat it must be 12volt. They are very inexpensive. Consider where you mount it. I now install mine (3rd trailer with Atwood heat, and wiring friends now) by the man door. That way you can turn it on or off without climbing in the trailer. No need to go larger gauge than the two blue wires from the Atwood btw as this is simply closing a circuit, an no load is carried by these wires.
Personally, I use 4inch PVC pipe as its cheap, easy to work with, and secures well to the trailer. I've found drilling the pipe directly into the vertical rails that the interior trim is screwed to works quite well. There is a number of ways that this can be done. Also, the pipes will get hot, so keeping that in mind, personally I now mount them closer to the floor so the radiant heat off them warms the floor and not the roof. Load a sled, and make sure your placement wont be a problem.
Finally, I trust your going with 2 six volt batteries wired in series, and not 12 volt batteries. You'll be much better off.
Have fun, your trailer will be POPULAR when its cold!
B
Bull
Well-known member
T/A, i notice on your install and a number of others that you have installed horizontally and used the optional outer access door. is it not a lot less efficient continually venting in outside cold air and running it in through the heater? (you can see daylight through the black plastic grate) i am planning on mounting vertically, and using flexible exhaust pipe (1 3/4 inch fits in exhaust pipe like a glove), to 90 it outside. as long as the exhaust is vented, there is no requirement for outside air. in an RV, there are several reasons for the access door and intake of outdoor air. they are most often installed in a tight, inaccessible space.....you need the door to access for repair, and there isn't enough air in the confined space to draw from.......not the case in a big 'ol enclosed trailer. yes? no?
another great idea that i partly stole from the old forum post........a timer wired inline with the thermostat. i am going to one up it......intermatic makes a digital programable 24 hr timer (can get it at home depot). i can set starting time, stopping time etc.....have it crank in the morning if we stay in a hotel.....nice and toasty. then crank up a bit before we quit.....toasty. then run for a while in the eve to dry things out. of course, a CO2 detector is a MUST.
another great idea that i partly stole from the old forum post........a timer wired inline with the thermostat. i am going to one up it......intermatic makes a digital programable 24 hr timer (can get it at home depot). i can set starting time, stopping time etc.....have it crank in the morning if we stay in a hotel.....nice and toasty. then crank up a bit before we quit.....toasty. then run for a while in the eve to dry things out. of course, a CO2 detector is a MUST.
S
Supplicate
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Why would that be? And what if someone was planning on going to a 24v setup in their trailer?
W
Wyoming T/A
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i think doing it that way you use inside air for combustion...GAS FUMES= BOOM
6volt vs. 12v.???
I'm the buddy Eludnu referred to. He said something about the 6 volt batteries having more capacity with their larger individual cells.
He wired mine up with a timer that can be set up to 3.75 hrs run time. The only hitch in the whole setup is that the horizontaly mounted RV propane tanks seem to be too large to mount under the trailer floor as intended
(24.4lb? Hmmm? maybe it's Gal. 15"x36" in anycase) . My Cargo Mate 26 will leave one of these tanks a bit too exposed (to grounding out) for my taste. the only option for under floor mounting seems to be to place the tank between the axles. Even there I think it would be inconvenient for filling and would still need heavy protection from rocks. I thought about a vertical tandk on the tongue, but there just isn't much room up there.
I'm the buddy Eludnu referred to. He said something about the 6 volt batteries having more capacity with their larger individual cells.
He wired mine up with a timer that can be set up to 3.75 hrs run time. The only hitch in the whole setup is that the horizontaly mounted RV propane tanks seem to be too large to mount under the trailer floor as intended
(24.4lb? Hmmm? maybe it's Gal. 15"x36" in anycase) . My Cargo Mate 26 will leave one of these tanks a bit too exposed (to grounding out) for my taste. the only option for under floor mounting seems to be to place the tank between the axles. Even there I think it would be inconvenient for filling and would still need heavy protection from rocks. I thought about a vertical tandk on the tongue, but there just isn't much room up there.
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B
Bull
Well-known member
TA, the furnaces work in the same way a garage furnace works. you vent exhaust (combustion air) outside. the air used for "heat" is air passed over the combustion chambers, no mixing of "burned" air. the fact is, if you have gas fumes (guess you mean fumes from the sleds?) you are going to have a boom problem whatever air is used. the spark from the ignitor is going to have indoor air around it either way. i know there are at least one or two guys on here who have done what i was talking about...running a single exhaust vent. otherwise, it is like leaving your bubble vent open 3 inches.
from the cheap seats
The only problem I see from drawing inside air is that you are doing just that, burning inside air.
Probably only a problem if you are using the trailer to sleep in....? Seems like drawing the inside air would be like using the "blue flame" heaters. I know they are equipted with low ox sensors.
Am I out to lunch (again
) or does this make sense? Bagger
The only problem I see from drawing inside air is that you are doing just that, burning inside air.
Probably only a problem if you are using the trailer to sleep in....? Seems like drawing the inside air would be like using the "blue flame" heaters. I know they are equipted with low ox sensors.
Am I out to lunch (again
) or does this make sense? Bagger
B
Bull
Well-known member
unless your trailer is airtight or REALLY small you aren't going to suck all the air out. now if you are burning AND exhausting into the trailer.......sure, you are going to quickly use up all the available oxygen (not really air)...then nighty night. any way it's done, you must use a CO2 detector. it is going to run way less not having daylight to the below zero cold air outside. like i said, EVERY shop/garage furnace works exactly this way and there is NO outside air intake.
Great discussion so far.
Someone already hit the battery issue on the head. The proper 6 volt batteries wired in series have a far better amp rating capacity per hour than 2 12 volt batteries wired in parallel. Sorry, can't answer the 24volt question, but I wonder if the furnace will operate at 24 volts? I'd have to take a look.
As for mounting the furnace on it's side, that is exactly what I've been doing from the first install. I have the tools, so it helps, but using a pipe bender, we make a new one piece exhaust that slips right into the furnace and allows us to mount it on it's side. I initially did it to take up the least amount of room in the trailer, but also find it makes the entire install cleaner. The other up side is the furnace is isolated completely from the elements, and my CO alarm only goes off if we run a sled inside the trailer. Never once has there been any issue whatsover with mounting it this way, and it's easier to mount the heating tubing too, as it starts off right up against the wall to begin with.
I'm also the one that does the timer circuit wiring that was mentioned, and use it to control all the additional electrical that is installed in the trailer. (search on the old forum and you'll find the post.) Added in cig chargers for cell phones, rechargeable battery charges for the beacons and radios, and rechargeable flashlights. Once I complete my new trailer next week I will post the electrical schematic on how I'm doing this, as a number have asked for it. Somehow Powderkeg convinced me to do the install on his first.
Someone already hit the battery issue on the head. The proper 6 volt batteries wired in series have a far better amp rating capacity per hour than 2 12 volt batteries wired in parallel. Sorry, can't answer the 24volt question, but I wonder if the furnace will operate at 24 volts? I'd have to take a look.
As for mounting the furnace on it's side, that is exactly what I've been doing from the first install. I have the tools, so it helps, but using a pipe bender, we make a new one piece exhaust that slips right into the furnace and allows us to mount it on it's side. I initially did it to take up the least amount of room in the trailer, but also find it makes the entire install cleaner. The other up side is the furnace is isolated completely from the elements, and my CO alarm only goes off if we run a sled inside the trailer. Never once has there been any issue whatsover with mounting it this way, and it's easier to mount the heating tubing too, as it starts off right up against the wall to begin with.
I'm also the one that does the timer circuit wiring that was mentioned, and use it to control all the additional electrical that is installed in the trailer. (search on the old forum and you'll find the post.) Added in cig chargers for cell phones, rechargeable battery charges for the beacons and radios, and rechargeable flashlights. Once I complete my new trailer next week I will post the electrical schematic on how I'm doing this, as a number have asked for it. Somehow Powderkeg convinced me to do the install on his first.
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eludnu,
Could you post a pic of how you mounted the furnace on its side
Could you post a pic of how you mounted the furnace on its side
B
Bull
Well-known member
all of the furnaces i looked at operate either 12v or 120v. you have to buy one or the other. i agree with the space saving. the biggest reason i am mounting that way is the outside intake is not needed, and it makes your furnace run WAAAYY more often.
my trailer has the fiberglas sandwich walls...probably a tad better for insulating than the aluminum walls. going to put 1 inch styro in the ceiling.
my trailer has the fiberglas sandwich walls...probably a tad better for insulating than the aluminum walls. going to put 1 inch styro in the ceiling.
2
2mileshigh
Active member
I run a suburban RV heater in my enclosed. Use 100% outside air much safer. Use a 12V marine battery , runs all weekend on it.
To answer the 24 volt questions. RV's that use FOUR 6 volt batteries are still 12 volt. You can install a battery selector switch that will switch from one pair of batteries to the other. Or, you can connect the batteries in a parallel/series connection. 6 + 6 in series = 12 volts. Add another pair of series wired 6 volt batteries wired in parallel to the first pair and you still have 12 volts.
That being said. Unless you are spending more than a weekend boon docking 4 batteries is overkill to operate a furnace.
S
Supplicate
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The reason I was asking about it is there is going to be a hell of a lot more stuff then just a furnace being run
