A minor victory: I finally sent my trusty ice chest to the luggage bay! Yep, my former 'pantry' - a 3-way Norcold fridge - is now making ice and chilling food (well, in my case, a couple sticks of butter). I'm so excited I woke at 4:00 AM just to check. l'm sitting here in awe, watching her (silently) working away.
Trouble is, I have only a 'one-way' power source: AC. No propane, no gen set, no house batts. So once I'm unplugged, no fridge. Unless... unless... I run it off my engine (starter) batteries? Only while running, you understand, just until the next power post.
I have a Vanner Equalizer but - like most things on my bus - it's not hooked up.
So, my question(s): 1) Can I tap a 12v supply off the Vanner? 2) How does it hook to the engine batts, and 3) how can I check it before wiring it to my (beautiful) fridge (so I don't ruin the fridge)?
Thanks for any help,
Nellie (the hostess with the mostest)
Nellie, you really need to connect the fridge to propane they are not efficient on 12v and it will draw a lot of amps and your 2 sticks of butter will be a liquid.
A 20 lb propane bottle will run the fridge for 3 or 4 weeks.
good luck
Running the fridge from the start batteries via the Vanner is a good solution for while the engine is running, and the fridge is already cold. The 12 volt draws a fairly heavy load, and needs to be wired with 10 gauge wire, but it won't cool the fridge down by itself. Propane requires a full installation of the venting system, which you can get away without if you run the fridge on electricity, and it's perfectly acceptable to run the fridge on propane while travelling. I find that the propane usage is quite low, I actually get a couple of months from one 20 lb tank.
Brian
your right Brian the side by side will run about 3 or 4 weeks on 20 lbs
good luck
I just have a houshold type fridge and it runs off the inverter just fine. I have solar panels that charge the batteries so that helps too. my batteries will run the fridge and the heat all night so no problem there. I didn't want an RV type fridge for the reason of the vent needed. Jerry
I think I am going to do a cost/benefit analysis of the propane RV type fridge vs house type fridge. Cost of install, cost of ancillary equipment, length of time off the grid, impact on boondocking, payback timeframe, cost per day of usage. It would be interesting to find out what's what. I'll have to price out generator run time, batteries, inverters, refers of both types, propane run time cost, etc. Could annoy me for quite a while ;)
Brian
Getting to be a long winter up there Brian? ;D
I took a house type out of mine to much generator time to keep the batteries up.
You could tell every bus at Quartzsite that had a house type the generators were running.
good luck
The guy next to us ran his generator 12-14 hours each day. I would think that gets a little spendy after a while.
Clifford,
I was running my generator mostly for heat I don't have a furnace installed yet. and the weather was cold enough to keep my food cold lol!
John
I just don't get the aversion to RV type fridges. Ours runs quietly and cold on propane whenever we are unplugged. I don't know how much propane it uses but we sure don't notice the consumption and we have to keep it turned to the 2nd from warmest setting or it will freeze things in the fridge compartment.
I think the aversion to RV type fridges comes from several places. I personally have one, and I hate getting up in the middle of the night to clear a no flame error code, and I can't rely on it to run without that happening on propane. Judging from the number of hits you get on google, "No FL" is a pretty common problem. So there's that. A lot of people don't want to cut the wall of the bus for the vent/service access portal, and they don't want to put a big vent cap on the roof. My bus has the roof vent, but no side vent. It has a vent hole cut into the floor and into a luggage bay. I'm not very happy with that, for a number of reasons, but it works fine and vents well, so I have yet to take a sawzall to the bus wall. It does mean that when I have to service it I have to remove the fridge from it's built-in hole inside the bus interior, disconnect the propane, take off all the trim, and physically move it into the hall way. Major PITA, and I did it three times last summer. The upfront cost of the fridge is high, they are pretty proud of them - $1400 for a 8 cu ft model like mine. And you have the whole propane thing. You have to build a propane cupboard to store the propane bottles, vent it high and low, run the lines, install detectors, worry about the whole fire issue, get propane inspections for your insurance company, while electric is so clean and not-nasty, and familiar.
Just some thoughts.
Brian
I vented mine to the outside bottom of the bus I have no side vents that won't happen on my bus.
It been installed 3 years now and I never had to remove it yet.
If you keep getting that code I would check the ground I had that problem till I grounded it to the frame
good luck
doubling up the ground is a good idea. Currently it would be grounded by the DC feed line, which is about a 20 ft long 10 ga wire, and I suppose the AC line if that is plugged in. Who know, maybe it only faults out if the AC line is unplugged. I never run it on AC, and I sometimes leave it unplugged so that I can plug in my battery charges, and I forget to plug it in again. I can't think of a reason not to run a separate ground strap. It sits in a wood cupboard, so it doesn't actually touch the bus chassis anywhere.
Brian
Quote from: Nellie Wilson on January 25, 2010, 03:21:18 AM
Trouble is, I have only a 'one-way' power source: AC. No propane, no gen set, no house batts. So once I'm unplugged, no fridge. Unless... unless... I run it off my engine (starter) batteries? Only while running, you understand, just until the next power post.
Nellie, please straighten us out:
Is this an absorption type fridge, meaning the kind that normally runs on propane, and you simply do not have propane hooked up? Or is it a compressor type fridge?
I ask because Norcold (or as some like to call them, Ne'erCold) makes both types. The absorption style is common on RV's; the compressor style is common on boats. Bus conversions might have either.
If you have the absorption style, then Clifford is absolutely correct -- these are not efficient at all on electricity. They are meant to be run on propane, and the electric inputs (which actually run heaters, with less output than the propane burner) are basically an afterthought, put there to take advantage of free (well, already paid for in your campground rate, anyway) 120-volt electric power when on shore, and/or to assuage fears that people have about running them on propane while under way.
In fact, if you intend to run mostly on AC power, with occasional inverter use while underway, then you will be much better served to sell the absorption fridge on eBay (despite their shortcomings, they are a specialty item and supply and demand keeps prices high) and run down to Wal-Mart and buy yourself a small household compressor type. I've seen them for less than a c-note. These small compressor fridges are much more efficient on electric power than absorption units.
If you already have a compressor style unit, then no problem just hooking it up to an inverter. But one caution: compressors really need true sine wave, not MSW.HTH.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Addendum: Upon rereading the original message, I see that you have an absorption unit. My advice to trade it for a small compressor style still stands.
If you are married to the absorption type because you plan to install propane later, my advice would be that it is probably better to just deal with the propane installation now, rather than fudge it to work off 12 volts on a 24-volt bus.
These things draw a huge amount of power on DC, and getting the Vanner install correct and properly fused will be critical.
If the concern is just a day's drive between power poles, try just filling the thing up. Use water jugs to use up most of the unoccupied space in the fridge. They will act as a thermal mass, keeping everything else cold while you drive. Same goes for the freezer: freeze some water or even Blue Ice packs in there. Try not to open the doors until you are plugged in again.
-Sean
In the daylight I shut off all ac and run on solar only. I think the TV draws mor than the fridge and with two sat systems going ( Dish & datastorm hughes ) the batteries get charged too. Jerry
PS i would put pix in but don't know how to do that.
FYI Nellie's refrigerator is a gas absorbtion type unit. Jack
OK, extremely rough back of the envelope calculations on the cost of running an RV fridge vs the cost of running a 120 volt compressor fridge "off the grid" - no hookups, only batteries and a generator. For the sake of argument I considered an 8 to 10 cubic foot fridge, because that's what I have. And all from scratch - no nothing to start with, and no other use for any of the equipment.
Propane RV fridge - $1400
Propane tank and rudimentary plumbing (a hose) - $100.
Half tank of propane a month (I get two months from a tank, small fridge I guess) $20/mo.
12 vdc to run the fridge controller - free, it's a tiny draw.
Total $1,500 plus $20/month running costs.
120 volt home style fridge - $500 (mid-range kinda nice model)
Energy consumption 375 kwh/year, 42 w/hr.
convert to battery power at 12 volt - 3.5 amps/hr
round up to 5 amps/hour inverter draw, call it 120 amps/day
At 50% discharge limit, you'd want 240 amp/hrs of battery for 24 hour cycles - $250
You'd want a 50 amp charger to recharge, call it $500 for a good one
You'd want a 2KW PSW inverter, call it $1,000
You'd want a reasonable generator to power up the charger - $1000 for a little Honda
Run the generator for 2.5 hours per day, half a gallon an hour, $112 per month for gas to run the gennie.
Total for house fridge - $3,250, and $112 per month.
Obviously there are other considerations, like "free" power from a hookup, using the inverter for other things, having the batteries to run lights, etc. But the stuff to run the fridge "off the grid" is not particularly cheap. On the other hand, once you have the RV fridge, it is cheap....
Feel free to take shots, I spent all of 10 minutes on this. It took longer to type than to figure out the numbers... ;D
Brian
Removed
I guess the best answer is "it depends". What are your future goals?
We used to have a 3 way fridge. It could kill a couple of batteries in only a few hours! Pulled a considerable load on the alternator of the car we were pulling the camper with too. So, based on my experience, I wouldn't recommend using your start batteries if the engine isn't running!
If you're planning on adding propane, start there. We've had great success with running our's on propane while driving or parked overnight.
If you're worried about a fire, good ole 120V has started more fires . . . . There is a good reason to follow "the code" on either installation. If properly installed & maintained, both are equally safe.
Concerning compressor fridges, the right house fridge with extra insulation & the condenser coils on the back & cold plates inside will use less electricity than a side by side frost free model. Another electricity saving option is to disconnect the heater around the door (it prevents condensation).
As for me, the price consideration is going to include the total picture - I want an inverter & battery bank large enough to run an AC unit while driving down the road & for several hours while parked. Often, the larger inverters come with an excellent charger built into them along with battery management software. So the inverter, charger & batteries will be there regardless of the fridge we use.
I'll also have propane to cook with. It is also a clean & quiet way to heat water. . . . Very convenient for boondocking too.
Quote from: bobofthenorth on January 25, 2010, 07:57:37 AM
I just don't get the aversion to RV type fridges. Ours runs quietly and cold on propane whenever we are unplugged. I don't know how much propane it uses but we sure don't notice the consumption and we have to keep it turned to the 2ND from warmest setting or it will freeze things in the fridge compartment.
If you experience an ammonia leak first hand in the confines of an RV, you will have a much better understanding of some of the aversion. Rare, but it only takes one time to shorten your life. :( I'm thinking the extra venting isn't required for the thing to work, but rather a path for the ammonia vapors to leave without filling the RV. The original owner of my Airstream lost a large part of his lung capacity when the fridge leaked ammonia when he was inside the camper & it was a factory correct installation. Permanent disability. :(
Our absorption fridge is set to the 2nd to coldest setting & ice cream is soft enough that you can serve it with cheap plastic spoons & never a fear of things in the fridge getting too cold or freezing. ;D
We seem pretty far afield from the OP question.
That said, I need to chime in.
First off, ammonia absorption refrigerators NEED TO BE VENTED TO THE OUTSIDE OF THE COACH. This is irrespective of whether or not they are being run on (or will ever be run on) propane. Ammonia gas is deadly; should the unit develop a leak in the absorption system, the gas needs to be able to vent outside immediately.
I would sincerely hope, therefore, that Viviane's fridge is properly installed and vented, and the reason she can not run it on propane is merely that the rest of the LPG system is not installed. Nellie: if this is not the case, I strongly urge you to install proper vents, or else remove the fridge. Again, I think you would be money ahead to sell it and buy a small compressor unit. (There, now its an on-topic post.)
We all have our biases when it comes to "the right way" to boondock or use a bus, and Brian, your very skewed math clearly tells us yours. I'm probably slightly biased the other way, but I would be the first person to say that an LP fridge is the right solution for desert rats who already need a large LP system for other reasons.
Among other things, a proper and safe LP system does not consist of merely "a hose," a compressor fridge of similar size and capability to the average absorption fridge is $150 not $500, and uses far less than 375 kWh per year, not even half that. Dallas's comments regarding maintenance costs are also germane; the last absorption fridge I had went through two control boards before I finally put a Dinosaur in it (highly recommended). Even one control board costs more than a whole new fridge from Wal-Mart.
If you want to get fancy, for the same money that buys you a decent RV absorption fridge, you can get an ultra-efficient compressor unit running on the 12/24v Danfoss compressor, such as the one I have, and reduce the energy consumption to a tiny fraction of that. I spend nothing per year to run my fridge, because my 330 watts of solar panels power it indefinitely, with power to spare. (More expensive, however, than an LP tank.)
As with so many things, it all comes down to how you use your coach. Some folks don't want to have to level the coach, even when parking for the day to do something elsewhere, which is another consideration with absorption refrigerators (whether they are running on propane or on electricity). Others don't want to cut more holes in the coach for the required venting, something compressor units don't need (although there must be airflow for the condensers to shed heat).
The big deal, for a lot of people, is that an electrical system is almost mandatory (you need it for lights, pumps, controls, fans, etc.) whereas an LP system is optional, and adds a great deal of complexity and safety concerns to a coach over one that is all-electric. If you are not using LP for anything else, such as heating and hot water, than putting it in just for a fridge can be a huge expense that may not be justifiable. OTOH, if, as I said earlier, you already have an LP system for other reasons, adding the fridge to it may be the best strategy.
FWIW.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
I put a lot of thought into fridges before changing over to the RV type as they are called.
It does take a lot of generator time for a house type fridge without solar.
The way Sean is setup with a large battery bank and on the move all the time that would work well for some but we never stay in over priced RV parks.
The RV gas fridge was my second choice a Sun Frost dc model was my first choice having had one in the past.
Think the RV fridges are expensive price one of those babies.
Kyle I do run my AC off inverters driving and my batteries will last a short period of time running 1 AC while stopped I can get about 3 hrs if it is not real hot the draw back is 1 AC will not keep the bus cool.
The RV fridge has worked for us without any hiccup's so far.
good luck
The one thing Sean usually brings up in the Propane vs. Electric discussions is travel ability - If your a traveler and not a parker - The restrictions placed for some tunnels, bridges and ferries can be quite onerous for travelers that have to travel significant miles due to propane restrictions - FWIW
Wow! "Food for thought," indeed!
But since I've already got the fridge, sounds like I should stick with it? It works great, and I can follow Sean's advice (pack it with cold stuff) between stops. At least until I hook up propane. I've got a couple full bottles so just need a regulator and some hose (I guess?). Anyway, I need it to run my stove and oven.
I shied from propane (partly) because I didn't want a hole in my wall; I'd considered venting through the floor but didn't know if that would work. But sounds like it does!
I was also concerned about fire and, if it flames out, CO poisoning (and still am). That ammonia thing Kyle mentioned doesn't sound so swell either.
As for servicing, I'm thinking of pulling it out from the wall and cutting a large re-sealing inspection port' in the enclosure (thanks for the thought, Bevans).
I also didn't want any holes in my roof. But since I'm stuck with that, thinking of using the frig vent for my holding tank and A/C vents too ... a '3 birds with one hole' kind'a thing.
No decisions yet, still reading and absorbing - but you guys got me thinking (not my longest suit). ???
Nellie
Niles, that maybe true in some parts of the USA but it has never been a problem for me.I grew up in Texas and go back 3 or 4 times a year and I have my first time for anyone to ask about propane on board.
I have been through the Baytown and Washburn tunnels 1000's of times same with the Bolivar and the Lynchburg ferries in Texas.
good luck
Quote from: luvrbus on January 25, 2010, 03:17:55 PM
Niles, that maybe true in some parts of the USA but it has never been a problem for me.I grew up in Texas and go back 3 or 4 times a year and I have my first time for anyone to ask about propane on board.
LP tunnel restrictions are a real problem in the northeast and on the west coast.
No LP at all is allowed in any tunnels in or connecting to New York City, as well as Boston. All of Maryland and Virginia tunnels allow only limited amounts (there are very specific rules) but the valves must be hand-closed at the tanks. Tunnels in California generally allow no LP or severely limit the amount.
As with many things, Texas has among the most relaxed DOT rules.
All of these issues are a matter of state or local law and vary widely.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Quote from: luvrbus on January 25, 2010, 03:17:55 PM
Niles, that maybe true in some parts of the USA but it has never been a problem for me.I grew up in Texas and go back 3 or 4 times a year and I have my first time for anyone to ask about propane on board.
I have been through the Baytown and Washburn tunnels 1000's of times same with the Bolivar and the Lynchburg ferries in Texas.
good luck
I took the class C across the bolivar ferry a few times. they always pull me aside and check that the propane is off and sometimes check for drugs illegals, ect. but aside from that no problemo.
That has never happen to me at Bolivar and I cross with my Eagle and toad a least 4 times a year last spring there were 4 of us from the Eagles group and they didn't pull us to side you must look suspect to them driving a class C LOL just kidding
good luck
Luvr - If only all the US was like Texas ;) With crazies packing their underwear with explosives, the next incidence involving ANY type fuel on any of those conveyances, accidently or on purpose, will probably bring on a whole new set of restrictions - These days not a matter of if but when - Your right that it probably won't affect many travelers, but for those who travel the Seaboards it can definetely put a cramp in our style - I carry a 20 lb'er for the belly grill (always off) If they ever try to restrict me I'd simply give it away as it's a whole lot cheaper than fuel for the detour and some of the best scenic views are before, during and after bridges, tunnels and ferries - FWIW
Yup, no matter if you are a conspiracy theorist or go with the flow...
How about this? Bin Laden's next best move is to use an RV or converted coach for the next bombing attempt, with an aging couple at the controls...
No amount of lobbying or other political pull will stop the wave of compliance that will rain down on our heads.
Anyone familiar with the treatment of the trucking community in the hands of the authorities knows what it might turn into.
The day after that, you'll find me walking, slowly, wearing only a thong, hands in the air...
oh, on topic, I'm supportive of all-electric, Nellie, install that fridge properly and stop screwing around, folks with long generator run times need to get a good charger, or more batteries, or better understand how to use their rigs.
happy coaching!
buswarrior
How about a little help on how to use our rigs BW batteries are batteries what ever you take out you put back I don't care what size of battery bank you have and these inverters and new chargers are going to do it their way.
I am not one for the power pole so the juice has to come from somewhere in my case it was the generator.
The way we use or coach total electric was the biggest mistake I made in the process IMHO
good luck
easy there... I was referencing the folks who were running their generators all day in Arizona, not you, my esteemed and learned busnut buddy!!!
happy coaching!
buswarrior
I think I may have heard this debate before. There are good points all around. For many, there type of use will dictate what is best. For others, like myself, it could go either way. I see the benefit of propane for cooking and heating first off. Diesel heat is great if you want to spend for it. Requiring the generator to cook seems a burden to me though. I like being able to run the frig on propane but could do without it too. We presently have an RV frig. If that died, I might just go with an equal size electric because of the large difference in price. I have done that before and managed fine.
The issue of bridge/tunnel restrictions is an important. Here is a list from Woodalls:
LP-GAS PROHIBITED:
Maryland/Baltimore: Baltimore Harbor and Fort McHenry (I-95) tunnels. Alternate route for RVs with propane over the Francis Scott Key Bridge is I-695.
Massachusetts/Boston Harbor: All.
New York/East River: Between Manhattan and Brooklyn: Brooklyn Battery Tunnel. Between Manhattan and Queens: Queens Midtown Tunnel.
New York and New Jersey/Hudson River: Between Manhattan and Jersey City: Holland Tunnel. Between Manhattan and Fort Lee: Lower level George Washington Bridge (I-95 South) and George Washington Bridge Expressway. Lower level Verrazano Narrows Bridge. Between Manhattan and Weehawken: Lincoln Tunnel.
LP-GAS RESTRICTIONS:
Virginia/Chesapeake Bay Bridge/Tunnel: RVs equipped with ICC-approved compressed cooking tanks not exceeding two 45-pound capacity tanks (or two permanently mounted containers with maximum total capacity of 200 pounds) may cross the facility provided that, in the opinion of the toll collector or police sergeant after inspection, the tanks are completely shut off and securely attached.
Texas/Houston Ship Channel: Washburn Tunnel between Pasadena and Galena Park: Maximum of two 71Ú2-gallon containers (30 pounds gas each) or one 10-gallon container (40 pounds gas) of DOT (ICC)-approved type, with shutoff valve at discharge opening. Valve must be closed when in tunnel. LP-gas as vehicle fuel prohibited. 71Ú2-gallon containers (30 pounds gas each) or one 10-gallon container (40 pounds gas) of DOT (ICC)-approved type, with shutoff valve at discharge opening. Valve must be closed when in tunnel. LP-gas as vehicle fuel prohibited.
Nellie,
You can maintain your frig with 12V if it is really cold when you drop AC power, but barely. In hot weather it won't keep the freezer temp properly.
My Norcold requires 12v DC even when on AC or LP, it operates the electronics.
The sooner you get LP hooked up the better, it works great going down the road and when you have no AC.
Also, be sure to follow very closely the dimensions for the vent duct behind the frig. It is supposed to be pretty shallow. In mild weather it may not be a problem, but in very hot weather the rear coils won't get enough cooling air.
One other point, until you add to your two sticks of butter, fill your freezer and frig compartments with jugs full of water (Or beer or wine, whatever, as long as it is liquid!). This keeps the frige temps stable and saves a lot of energy once the liquid is cooled. The most expensive thing to cool in a frig is air.
Quote from: luvrbus on January 25, 2010, 07:43:59 PM
I am not one for the power pole so the juice has to come from somewhere in my case it was the generator.
The way we use or coach total electric was the biggest mistake I made in the process
Are you saying that to be all electric was a big mistake?
Can you offer some reasoning, because I will not install gas because of the restrictions in so many places I travel. Also because it will be difficult to install tanks, etc. without messing up my underside layout.
Keith
PCC
A sight I might prefer to be spared:
Quote(From BW): ...you'll find me walking, slowly, wearing only a thong, hands in the air...
Though who knows... might be sorta cute? :D
But BW, what's this supposed to mean?
QuoteNellie, install that fridge properly and stop screwing around...
Not to be thin-skinned, but didn't realize I appeared to be "screwing around." Thanks for the thought.
Lin: Thanks for that precise info. Doubt I'd ever venture into such places, but your post is sure worth a 'just in case' printout.
Gus: Thanks for the benefit of your 12v experience... seems like most everybody concurs. Think I'll just by-pass batts as a power source (unless in some emergency). BTW, since you have a Norcold, do you know where that DC heater wire connects to? The schematic shows a 30 amp (automotive) fuse, but no such animal on my fridge. Maybe I'm supposed to install an in-line fuse?
Or is it even necessary if I don't use 12v power supply? (My
AC heater is hooked up per the Norcold manual).
Thanks again to all,
Nellie
You're supposed to install a fuse on the DC power supply. To be honest, I didn't know the Norcold (what I have as well) would actually work on just AC, with no 12 vdc to run the computer, but who knows, if yours is working, it's working, bottom line. A lot of people use a DC distribution panel set up with a dozen or so automotive fuses as the centre of their coach DC system. I ran 10 ga. wires back to there, not because I plan on running the fridge on 12 vdc as I don't have on-the-road charging of my house batteries yet, but because I couldn't guarantee that the fridge wouldn't ever get stuck on trying to run from 12 vdc for a short period of time - the computer controls include an automatic power source function, and if there is no AC supply and the propane runs out, it might switch to 12 volt even if I didn't want it to. So I wired it to allow 12 volt operation even if I don't plan to use it. Anyway, it draws 15 amps on 12 volt, and is supposed to be fused for 30 amps. On mine the connections are two 1/4" spade terminals on the controller board on the back of the fridge. If you know the model number of your fridge the manuals are pretty much available on line, useful for things like maintenance and error codes and such.
My vent is from the luggage bay up the back, over the top, and up to the roof about 24" in from the side of the bus. It's important to construct that vent so that it's quite air-tight to the inside of the bus, to keep combustion byproducts out if running on propane, and the whole ammonia thing that Sean points out. It is perfectly acceptable to route your other vents there as well, as far as I can see.
BTW my little riff on the costs of electric vs RV wasn't supposed to show any bias, I just wondered what the start-up cost of each route was, buying retail and starting from nothing. Obviously there are other advantages and ways to go about it, including getting a fridge when you bought your bus, which is what I did. If I was starting from scratch I would almost certainly go all electric, I think, but the cost of the inverter and battery bank to support that in a meaningful way is still a pretty major hurdle. But I think the costs get built into the over-all cost of the conversion and there are indeed other benefits to increasing the flexibility of your power sourcing.
Brian
Nellie,
Do you have an inverter or plan to have one? I use my inverter to run the fridge while going down the road. (mine only runs on AC or Propane). When I'm parked with AC, that's what I use. When I'm dry camping, I use the Propane. Works GREAT!
For venting through the side of the bus, I was able to carefully remove the skin of the bus only. I looked carefully at the bus structure from the manual, checked the rivet patterns and it worked great. I did a lot of thinking in general about where to put appliances (furnaces, water heaters,..) to really do as little cutting to structural pieces. Good luck!
Glenn
Boy, Nellie, you've gotten a lot of responses, and LOTS of opinions. I guess I could tell you my thoughts and add to the confusion :D.
If you use the rv style fridge, they ARE expensive, but often you have three choices for operation, 12v when running down the road, a/c when you have a good source of electric, and LP when you want to boondock for extended periods of time. Each one has limitations, the 12v sucks batteries down and cools the least, a/c cools better but needs power, and the lp eventually will deplete a smaller propane tank in about two months, although it cools the best. The advantages of rv fridges are that they are designed for our application, a moving vehicle, multiple sources of energy, door locks, mounting brackets, etc.
When installing an rv fridge, read the installation directions and clearances carefully. The sides are often 0" clearance and normally, the rear clearance from the wall to the coil is often 1/2"-1". The top rear of the fridge should be baffled or sealed flush with the back of the fridge, if you can visualize this: the air should enter from the outside grill, just below the bottom of the coil on the back of the fridge. The fresh air should be forced to channel up through the bottom of the coil and on up between the coil loop, existing through the finned condenser at the top, and out the roof, with no place else for it to spread. Often, people add a small kilson thermostat to the condenser fins and add a small computer style 12v muffin fan to force the air to follow this path, or at least to "blow" air across the condenser. The fan shuld not be necessary on a properly installed fridge, but even the fridge manufacturers are recognising that very few fridges are installed properly.
The disadvantages of rv fridges are that the fridge needs to be "relatively" level when operated, they are pricey, and certain ones have had problems with the elctronic controller boards, hence the production of "dinosaur boards", which is a board you can buy for pretty much any rv fridge that seems to be more durable, as per anecdotal info available.
Many people swear by a/c fridges, and they are truly less expensive and seem to control inside temps better. Many people operate them on total electric buses with good battery banks and either run solar panels and/or generators to replace the energy used.
Disadvantages are that it is much harder to properly mount a home fridge, you are tied to ONE source of energy and if you have a problem with your electric system, you're pretty much going to be buying a cooler and ice until you get it solved. The home style refrigerators are not "approved" for mobile installation, not that I've heard of this being an issue for most people.
As for venting, even the freon used in home style refrigerators is dangerous, and if parked in warm areas, if you don't have ventilation, you will increase the amount of heat inside the coach. A condenser needs to reject heat and it has to go somewhere, facts are facts.
For us, we've had rv's for a lot of years, and recently purchased a Prevost with inverters, big battery banks, and solar panels, but I will keep my propane. I'm a redundant type of gal and I like having choices. . . if I have a problem with the lp, I can run on electric, if I have an inverter go down, I can run on LP. . . I just like having choices. Having worked on plumbing and hvac for quite a few years, I have no more fear from LP than I do from electric, each has it's dangers and each can start a fire. Personally, I find a propane system to be pretty simple, not a lot going on there, not a lot of components in line to fail, etc., and lots of energy output.
When making decisions on your coach, keep an open mind, learn all that you can, listen to all opinions, and decide what works best for you. But, also remember that often, the reason you see the majority of people going in a certain direction, is that it's the most sensible for a wide variety of applications. There's nothing wrong with choose a simple path. . . you're not out to impress anyone, you're just building your bus to serve your needs. Good luck, and remember, ymmv, Christy Hicks
screwing around = installing in stages
The brevity of the short last bit required a delivery that is impossible to convey in the written word.
I will refrain from attempts at comedy.
happy coaching!
buswarrior
QuoteFrom BW: I will refrain from attempts at comedy.
BW: Please don't! Blame my misunderstanding on my limited translation skills. You've given me some great tips - and I've had a lot of yucks, 'thongs' to you :D. And, actually, I agree with your assessmnet... but I'm stuck having to do things in stages. Traveling and living in this thing, and fitting it out on the road takes some juggling. Usually complicated by putting out one mechanical 'fire' or another.
Christy: Thanks for the specifics. I've got the 0" side clearances established but the coils / condensor are 8" from the outside wall (due to head room and roof curvature restrictions). Too much? I can change that, but only with a major re-design.
Tenor: Yup, got a little 1000 watt (continuous) inverter (out of an 18-wheeler). Not that it matters, seeing as I have no batteries to run it on :'( .
Bevans: Pardon my poor explanation. I do have 12v power running the fridge computer. I just can't figure out the hookup for the 12v fridge heater.
Thanks again to all.
Nellie
Nellie,
FWIW, we have a regular AC house fridge. We are all electric. We have a generator, and a bank of 6 8D gel batteries. We usually go about two days, before we need a charge. We will hook up our alternator to the inverters, that way we can charge as we drive. But that will happen in the future.
God bless,
John
Nellie: Bevans: Pardon my poor explanation. I do have 12v power running the fridge computer. I just can't figure out the hookup for the 12v fridge heater.
It's the same connection on my Norcold 841, there is only one 12vdc connection for both the computer and the heater. The fridge figures out how to get it to the heater. That's why I wired it with a 30 amp fuse and the 10 gauge wiring - it could decide to pull 15 amps and run on the 12vdc heater for some oddball reason, and I wanted to have the wire and the fuse in case it did. Maybe your fridge controls things differently, but mine has an auto mode where it searches for a power source. If there is nothing else, it will try the 12 volt source.
edit: I have a soft copy of the manual for the n600 and n800 models. It has wiring instructions and venting installation diagrams, dimensions, all of that. I can email it to you if you like, just ask.
Brian
Temporarily, you can fashion an air dam from the outside in, but lifting the vent access panel (if you have one), and cut a piece of sheet metal (I used a cookie sheet one time) that blocks the air from the top of the door opening across to the bottom of the condenser coil on the back of the fridge. . (you want the air to NOT be able to get up between the outside wall and the outside edge of the coil on the back). . . when I did it, mine was foil taped to the inside top of the door opening and angled up and leaned against the bottom of the condenser coil and was again foil taped to that tube, until I could do a better blockout.
Later, if you have to pull the fridge, you simple build a baffle or box against the outside wall that allows you between 1/2"-1" clearance between the coil and the wall on the back. I would strongly advise that this box have a sheetmetal covering, JUST IN CASE you get a leak somewhere on the pilot assembly and get a nasty flame trying to come out where it shouldn't. . . . most of the time, there's all kinds of wood around those fridges, but I like to line with sheetmetal whenever I can just for EXTRA safety.
Actually, I've seen WAY more coaches with gaps like yours in the back than I have seen installed properly. . . and this is from major coach manufacturers. I was pleasantly suprised to see baffles on the sides and tops of ours in this Beaver conversion, even though they STILL had way too much space behind it. If there's too much space behind the coil, the air can waffle around behind it and up through the roof vent, instead of being forced inside the loop formed by the coil and up through the fins at the top. Does this make sense or am I just too obtuse. . . it's hard for me to explain it properly so you can picture it, I'm afraid.
Well, back to my paperwork. . . today is a "working" day :'(, so that we can play tomorrow, :D ha ha. Christy Hicks
There you go guys John 316 said it
3000.00 dollar battery bank
6000.00 worth of inverters
12,000.00 generator
If you are going to have a total electric coach that is the way you do it he did not mention run time a wild guess 5 to 6 hrs to bring the batteries back to full charge,I have the tee shirt
good luck
lol, Clifford ;D. I guess we are the poster child why one should go with propane ;D. I can't wait until we have the alternator hooked up. Then we will be smoking. lol.
God bless,
John
Christy: Thanks for your explanation(s). I know these 'little posts' take time to compose (at least the more thoughtful ones :)) Still trying to wrap my pea brain around it all, but it's much appreciated. (And that goes for everybody!)
Bevans: Okay, I'll bite... send me your missive :) - and thanks in advance!
LuvRbus : If that's what John316 says, who am I to quibble? Let's see, 20 Grand or 30 bucks for some hose and such? Hmmm... count this chicita as LP all the way, Jose.
Still scratching my head... but not nearly as much,
Nellie
Nellie;
I don't get into these topics very often because I don't have much to contribute and although you have been given good advice there are a few things i don't see. First make sure the fridge is hooked down so it wont move around, second put in a good LP gas detector and a good carbon monoxide detector.
We have lost enough people to natural causes, I don't want to read about you or any one else being lost to our own screw up's.
Don
Thank you, Don -
Your concern is most appreciated. And your caution prompts this question:
If I have an LP 'flameout,' does the gas stop flowing? Several posts indictate I'll get a 'warning ' on the fridge monitor, but if I'm driving or Zzzzz'ing away, that's not much help . Or, worse yet, away from the bus. I have visions of popping open the door, cigarette in hand and... KA-BOOM! (I know smoking kills, but I'd rather it be more gradual).
Nellie
If the flame goes out the gas will stop. Same is true of your gas water heater and oven. Stove tops though must be manually turned off. It is a pretty basic function of all but the simplest gas devices like a blow torch or bottle top Mr Heater.
Nellie, like Lin said the gas will shut off with no flame there is a thermocouple the pilot heat the coupling and opens the gas valve if the flame goes out the valve closes.
good luck
Quote from: Lin on January 27, 2010, 04:48:27 PM
... Stove tops though must be manually turned off. ...
FWIW, my cooktop shuts off automatically if the flame goes out. Pretty much all marine models do this.
Also, note that you are required to have an LP detector that turns off the gas supply if LP is detected in the coach. One of the reasons I wrote that it's not as simple as "some hose."
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Sean, what brand is your cooktop the reason for asking 2 years ago I bought a Gaggenau gas top and never installed it because it has a 110v ignition for the burners.
good luck
Quote from: luvrbus on January 27, 2010, 06:23:04 PM
Sean, what brand is your cooktop ...
It's a "Princess" 2276 by Seward, which is a very common marine brand. Lots of high-end coach builders use these, too, and I picked it up cheap at an RV surplus joint.
http://www.seawardproducts.com/2276.htm (http://www.seawardproducts.com/2276.htm)
Each of the two burners has a thermocouple connected to a solenoid. Depressing the control knob simultaneously opens the solenoid and operated the ignitor, which in this case is 12 vdc. You have to hold the knob down for perhaps a full second or so for the thermocouple to heat up, at which point it will hold the solenoid open and you can release the knob. You then adjust the flame as normal. If the flame ever goes out, the thermocouple cools off in less than a second and closes the solenoid, shutting off the gas to that burner.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.seawardproducts.com%2Fimages%2F2276.jpg&hash=c9865c5e9823cd6e21557c91ad29735050756a03)
I love it, but as I have said before, if I were doing the coach over again today, I would omit the LP system altogether, and use a pair of 120-vac induction hobs for cooking. (We do have a single counter-top induction hob as well, and we use that exclusively if we have shore power, and sometimes even when we don't.)
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Sean, can you site the code that requires an automatic shutoff if gas is detected? I've never heard or seen that before and I just called a friend that owns an rv shop and he thinks your blowing smoke. I think it would be a good idea but none of the factory units I've had ever had anything like that, and I've called most of my friends that have new units and they don't have anything like that either, but like I said I think it's a good idea.
Cody, the marine world $$$ is different from the RV stuff the Gaggenau stove top I have works the same way except it uses 110v no flame no gas.
good luck
Nellie,
Christy has pretty well covered the vent thing. In short, the vent chimney needs to be shallow so all the cooling air entering the bottom flows over the heated coils before exiting the top. This is very important. Your 8" clearance allows most of the air to exit the top without doing any cooling.
"Automotive fuse" doesn't mean you already have one, it means you need one. An inline holder for one of these is easy to find at WalMart or a parts store. Please note, as already posted, that this will take a 10 gage wire because it draws so many amps, the reason for the 30amp fuse which is pretty big.
I'm very surprised that yours works with no 12v DC input, mine won't do this? However, mine is pretty old.
We've only used the DC frige operation in emergencies.
If my frige blows out it will automatically restart if conditions are favorable, like no strong wind/rain.
QuoteI bought a Gaggenau gas top and never installed it because it has a 110v ignition
Hmmmm, our new coach has a Gaggenau cooktop in it and I just assumed it was 12v for the ignition. (I have to get used to having a thermocouple of the burner. . .used to just lighting it and it being on. . have to hold the knob down for a few seconds before letting go now). I'll check and see if it's 110v on the ignition when we get back from LA. . . .left the bus in Quartzite and took a few days before heading south and back east. Sounds like they're getting ready to get more crappy ice in Oklahoma anyway.
I believe Sean is talking about the LP gas detector that shuts the gas off if is "sniffs" propane. Ours in the little class C will even cut the LP off if it sniffs exhaust fumes from the water heater. . . which is right next to the entry door, doggone it!
Nellie, the guys are talking about the safety valve on most gas appliances. In most situations, when you light the pilot or flame, the flame heats up a thermocouple which generates millivolts and greates a magnetic field, "holding" the solenoid in on the gas valve, to keep the gas flowing. If the flame goes out, the thermocouple cools down extremely quickly and drops the power to the solenoid, dropping the pilot or flame out. The big problem you will experience if you are asleep and the pilot on your fridge goes out is that your beer may be a bit warmer in the morning. >:( I usually deal with this situation by keeping the beer in the coldest part of the fridge, and if necessary, throwing a couple on top of the partially defrosted freezer goods until the fridge cools back down. :D
Christy Hicks
I realize the marine stuff is differernt, but sean states that a leak detector is required to shut the gas off if a leak is detected in a coach, when he says coach that would indicate an rv to me, I know most appliances will shut the gas off if the pilot light goes out, maybe thats what he's talking about but nobody i called is aware of a required leak detector being mandated. The reason I'm questioning this being mandated is because I spent several days going thru the LP system of a friends 2006 coach trying to find a leak, we could smell it but had a hard time locating it, was a bad flare on a T, but there was no leak detector in the system, we went from the onboard tank to each appliance looking for the leak until we found it
Cody,
I am a bit at a loss here to answer you fully, because I have an older copy of the code.
Since at least 1996, NFPA-1192 has required all RV's with any LP system or appliance to have a permanently installed hard-wired LP detector. The section from my 2002 code reads:
6.4.8 LP-Gas Detectors. All recreational vehicles equipped with an LP-Gas appliance and electrical system shall be equipped with an LP-Gas detector listed as suitable for use in recreational vehicles under the requirements of UL 1484, Standard for Safety Residential Gas Detectors, and installed according to the terms of its listing.
However, the code is updated regularly, and my understanding is around 2005 (IIRC), the requirement was added to connect the detector to a solenoid valve capable of closing off the flow of gas.
I should note, however, that even my bottom-of-the-line 1995 Fleetwood motor home came with such a shut-off solenoid connected to its LP detector, and most commercial RVs built in that era had similar systems.
Perhaps someone who has access to a post-2005 edition of NFPA-1192 (and/or UL 1484) could chime in here with the correct language (or correct me if I am wrong about this).
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Clifford,
If the cooktop requires 110 volts, would it work off the 12 volt using one of those cheap, little, cigarette lighter inverters (hard wired, of course)?
Update:
I did not realize it earlier, but my NFPA web site subscription actually allowed me to have a look at the 2008 code (in a really crappy read-only interface where you can't search, copy, or print anything).
I hunted around in there, and what I found is that the code was updated to specify the location of shut-off solenoids, but does not mandate them:
5.2.11.1 Vehicles shall be permitted to be equipped with a remotely controlled, normally closed, electrically operated shutoff valve installed within 9" of the outlet of the tank shutoff valve ...
The wording of the detector requirement is unchanged from my copy.
So, apparently, there is not yet a mandatory requirement for automatic shutoff based on LP detection alarms (but I would not be surprised to see it in the 2011 edition). Therefore, your RV-shop friend was correct, I was, it seems, blowing smoke. Mea culpa.
That said, the detector requirement is very real, and the price difference between detectors with and without the solenoid feature appears to be around $20. That's what we used in our system here on Odyssey, and, as I wrote earlier, even my cheap-o Fleetwood had one 15 years ago. I could not imagine wanting to have LP appliances indoors, such as cooktops, ovens, or refrigerators, without this simple and inexpensive safety device.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Christy: Love the way your mind works! :)
QuoteFrom Christy: The big problem you will experience... is that your beer may be a bit warmer in the morning. I usually deal with this situation by keeping the beer in the coldest part of the fridge, and if necessary, throwing a couple on top of the partially defrosted freezer goods until the fridge cools back down.
QuoteFrom Sean: I was, it seems, blowing smoke.
Sean: Blowing smoke or not, that automatic cut-off thingy seems $$$ well spent. Whenever I get LP hooked up, that little item will be in place. Just the peace of mind is worth it. Thanks for the tip.
Gus: Thanks bud! I'm sealing the compartment now, and will install a (removable) baffle to force air through those coils (per Christy's suggestion). Question: Is it okay for the air to flow over the condenser as well? Or should I steer it away from that?
If you get a minute, hop over that LP Flame-out thread? I describe that wire - my 'wire to nowhere' - in more detail. I'd value your input.
Nellie
Quote from: Lin on January 27, 2010, 04:48:27 PM
If the flame goes out the gas will stop. Same is true of your gas water heater and oven. Stove tops though must be manually turned off. It is a pretty basic function of all but the simplest gas devices like a blow torch or bottle top Mr Heater.
That may be true if everything else is working properly, if the safety valve malfunctions, the gas could still flow.
There are numerous other places that can allow gas to escape, hence the reason for good ventilation & gas detection.
Sean, I was going to post that I was pretty sure that the gas solenoid valve was not required. then I saw your latest post.
When I install my fire suppression system, I always try to talk the owner into that kind of system. Then I can wire the solenoid valve into my system so that I can shut off the propane if a fire is detected.
I would say that perhaps 50-60% of the coaches made in the last 3 years have the valve, but many do not (not a very scientific survey). There does not seem to be any logic as to what coaches have them. I have seen the valve on medium level coaches and some top end coaches do not have them.
When I did a system without the valve I would install a CCI 7719 system. Unfortunately they are out of business. I have done a bit of searching and I can't find a detector that is equipped to operate a solenoid valve. I have wonder if the new coaches have a vendor for that type of system?
Jim
Sean, what puzzled me is that the automatic shutdown system is offered as an option on many coaches, it seemed to me that if it were mandated then the option would be a moot issue. Like I said I can se the merit in having the system tho. Blowing smoke is ok too, I smoked up until 11PM july 10th 2008, thats when I had my heart attack. Just as a sideways note, my 1978 Revcon has the automatic shutdown system built onto the end of the built in LP tank, so those systems have been around for a while.
JIm, I can check and see about the availability of the soliniod, the rv shop guy I was talking about is don from marathon, he's their design engineer, it's a little early to call him tho, I get better answers if I don't call him in what is concidered the middle of the night on the west coast lol.
Quote from: rv_safetyman on January 28, 2010, 06:01:52 AM
When I did a system without the valve I would install a CCI 7719 system. Unfortunately they are out of business. I have done a bit of searching and I can't find a detector that is equipped to operate a solenoid valve.
Jim, the Safe-T-Alert model 70 from MTI Industries has a solenoid contact:
http://www.mtiindustries.com/re6.htm (http://www.mtiindustries.com/re6.htm)
That's their top of the line; it does not look like any of their simpler units has the contacts as yet.
Now that most of the old CCI product is out of the distribution pipeline, I would expect to see someone step in to fill the giant void. Possibly MTI, who have already recognized the opportunity, to the point that many of their LP detectors fit CCI cutouts (not the 70, unfortunately).
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Hi Sean. Thanks for the link to SAFE-T-Alert site. I have been there several times looking for a total system. I missed the fact that their model 70 has a relay that can control a solenoid valve.
I did not see that they sell or recommend a specific solenoid valve. That creates a problem for me, as I can't be in a position to select a valve and then be responsible for the selection. I can get the valves that CCI used, but they are 9V solenoids and since they are continuously on, I don't think applying 12 V would be a good idea.
Jim
Jim, you might call MTI to see if they have a recommendation. Alternatively, go down to your local RV dealer and poke around their showroom to find out what the big names are using. Another option is to spec one of the valves that Atwood, Dometic, etc. use internal to their appliances, although you'd need to make sure it had a large enough orifice to be a full-system solution.
As long as you pick a valve that is UL listed for the application, I think you'd be OK. But I understand completely why you don't want to be the "engineer of record" for such a system.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Nellie,
I'm not sure your frig has a condenser? I haven't looked at the installation instructions since I corrected mine. I guess you could consider the return coils as a condenser but it is a different process altogether than a home freon system.
I understood that your frige is new so if you construct the baffle according to the installation instructions you will be ok. Understand that the instructions also describe installing without a roof vent (Which they don't recommend) and, as I remember, it is easy to get the two different installations confused. Mine came installed in the bus with no exhaust vent of any kind!!
Also, as someone else posted earlier, be sure to completely seal all around the top of the frige to keep the exhaust gases from coming out there. This will also keep cold air from outside out of the bus since the cooling air intake is directly from outside.
If you have no installation instructions I'll check mine tomorrow.
I posted to the other string before I saw this one so I hope I covered your question.
Thanks Gus!
My diagram calls it a 'condenser,' but I call it "a thing on the back, near the top, that sticks out and looks like a little radiator."
No roof vent? No exhaust vent at all? Much as I'd love that, I'd be too scared to try it. As for installation instructions, mine say almost nothing. Just one line of text that says, basically, 'allow at least 8" of clearance between the coils and the facing wall.' Not much help.
Anyway, I'm going with a 4" (flapper cap) exhaust out the roof, and two 2" holes in the floor. I've sealed the interior 'fixed wall' and sealed above the fridge (which I may eventually insulate?) And I added some insulation to the fridge sidewalls. The tricky part is the service access wall; it's got to be easily removable but (somehow?) sealed. Still working on that.
(Since I opted NOT to cut into my stainless, I need the removable wall to service the fridge. I'm may also keep a dedicated fridge battery in there, with external charging terminals.)
But it's all subject to change (Lord, isn't everything?) depending on what happens when I install propane. I'll have that done by a pro - or at least someone smarter than me - and they can tell me if I need to modify my (almost) existing installation.
Thanks again,
Nellie
Nellie,
If the diagram says it is a condenser then it is, I couldn't remember for sure since it has been a couple of years since I installed my baffle. 8" is also correct if it says that. As I remember mine is much less, but mine is probably ten years old.
I also cut a hole in my roof after I discovered that it was required, but it came with no exhaust at all!! I had never owned an RV before this so I was completely ignorant of the need for an exhaust vent. I guess the only thing that saved us was that our 4104 leaked air like crazy!! Needless to say I went into shock when I finally read the installation manual. I installed a regular RV roof vent which is considerably larger that a 4" pipe.
I really don't blame you for not wanting to cut a hole in the side but mine was already there. It does make for easy servicing though, I once had to replace the circuit board and it was relatively easy. I recommend that you just make the frig easy to slide out from the wall for service, it won't have to come out very far for most service. They are not very heavy. The LP line can be installed with a couple of big loops in a copper line or you can use a flexible hose for part of the line.
Both sides of my frig are covered by 3/4" plywood which also double as a closet wall and a bunk bed wall. I slide the bunk beds out of the way and remove that wall with only four screws.
It seems to me that two 2" intake holes and one 4" exhaust hole won't provide enough air, but, if the directions say so, it is so! My frig is 6 cu ft. If yours is smaller then 4" may be enough.
I don't recommend a separate frig battery. Batteries spill acid and give off fumes when being charged, you really don't want that inside the bus. You surely can find a DC wire somewhere near the frige and eliminate worrying about another battery. The wires to the old passenger reading lights are pretty heavy because there were so many lights.
My LP setup is two 20lb bottles like on BBQ grills. They are mounted on a two bottle holder like on RV trailer hitches. The big advantage to this setup is that you can remove the bottles and carry them to be refilled and you always have a spare. My original tank was permanently installed and it was a real pain to find a refill station I could get into. It was a monster and only held 10 gal!! Two 20lb tanks take much less space and hold the same amount. (Pounds/gallons are confusing, but the tanks are listed in pound size and when you get them filled it is in gallons!! One 20lb tank/bottle holds appx 5 gal). I also have two more 20lb tanks in another compartment for my heater, which I don't use very much. These provide plenty of LP backup.
20 lb tanks can be purchased at Home Depot for around $28. The tanks you see outside stores in wire cages for exchange are only about 18 gal although they are almost as large in physical size. They can be used as well but you are better off owning your tanks and getting them refilled, much cheaper in the long run.
Sorry, didn't mean for this to get so long!
Nellie,
I had to go out into the snow anyway so went by the bus and got my manual.
It shows that the rear clearance between the condenser (Yes, it has a condenser!) at the top and the larger coils at the bottom should be no more than 1".
If the clearance is more than this (you said yours is 8") you need two small horizontal baffles the full width of the rear opening which come to no less than 1" each coil.
These force the rising air to flow through these two coils.
In the vent diagram these baffles are very small from the edge so they are easy to miss. You don't need a large vertical baffle unless the frige is more than 24" from the bus wall.
Again, these are the instructions for my Norcold Model 683. Yours may be different, but look carefully at the side view vent diagram in your instructions and you may see them. They are identified as number 5 in my diagram.
Gus -
Okay, point taken... I went with a bigger hole at the bottom, but am stuck with the 4" chimney (already bought the pieces). BUT (taking your advice) ran my holding tank vent separately (so it takes no air space). Also, my A/C vents into the fridge 'chimney,' directly below the coils. The A/C exhaust acts as a fan to increase air circulation when the fridge needs it most... when it's hot.
Hard to visualize, I know. I'm gonna try to post a couple photos to give you the picture. :) Let me know your thoughts? I'm kinda sawing... reading posts... sawing... reading posts... plugging hole... reading posts...
Just learned I can only post one pic per post(?)... so I'll make another couple of posts. Sorry for the inconvenience.(//)
Nellie
If the (eventual) propane installer says 'change it,' no problem - I'm cutting the holes within the perimeter of a (potentially) larger vent.
Another...
Another...
This is stupid, but just one more. I'm taking my own thread off topic, but during 'breaks' I'm refreshing my wheels. A lot more fun and makes for much better 'bus porn.' ;D
Viviane,
I'm not sure where to start here, but I have several concerns about the photos you've posted.
Let's start with the fridge:
- I do not see a direct outside air inlet for combustion air. Not a problem until you connect the propane, but once you do, there needs to be a direct source of air in appropriate quantity from outside the rig. This is usually accomplished with a side vent at or below the level of the burner.
- I also do not see a vent for the products of combustion, aka a "chimney." This needs to be a direct vent through the roof at the highest point of the chase, or else you need an air-tight baffle and a side vent at the top just below it.
- I do not see any escape for an unexpected release of ammonia. This requires a vent at the lowest point of the compartment directly to the outside. Usually, this is the same as the fresh air intake for the burner.
- If the air handler I see in the photos is discharging condenser air into the compartment, this will severely limit the refrigerator's ability to cool. Condenser air should be discharged directly to the outside environment.
I am also very concerned about the holding tank vent. This must go through the roof in a direct and continuous manner. Also, there can be no negative slope as shown in the photo.
I suggest you correct these things ASAP. The fridge venting issues can kill you. The sewer vent issue can make you very sick, or in severe cases cause an explosion in the coach.
FWIW.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Nellie, I'm not sure I know what I see in the third photo, but the first two tell me you need a vertical baffle within 1" of the condenser coil (I think that's what I see at the top of pic #1?) and also the large coil at the bottom. There is too much space between the wall and coils for cooling air to work properly.
This will put your waste tank vent in its own separate compartment. I don't remember posting about this vent but I may have??
I don't know what I see in the third photo? If the AC exhausts cold air into the frig chimney that is probably a waste of AC output. However, in addition to what Sean said about decreased frig efficiency, hot exhaust from the AC condenser will most likely choke down the AC and make it overheat unless your frig chimney is very large. The hot exhaust from an AC cond does not have a lot of "push".
I still don't think one 4" vent is large enough, I don't even think two 4" vents will be enough. You need to check the installation instructions carefully. Most RV frige vents, including mine, are much larger than this. Mine is 24" x 5.25" as required by my instructions, so even two 4" pipes will only be appx half this large.
It is probably a good idea if you email me directly with photos, then you can send as many as you like and they will be much larger so I can see what I see!!
egusDOTcATcenturytelDOTnet.
Sean,
She said she has two 2" holes in the bottom for intake air and a 4" exhaust hole at the top. It isn't clear to me if the intake is from outside or from the baggage comp but that is a good point about ammonia gas (LP as well).
I don't think this is enough air but it depends on what her installation instructions say.
Sean & Gus -
I'll try to answer both your posts, as briefly as possible.
First, to clarify, I haven't yet cut any ceiling holes; that project (maybe) begins today.
But, per your (and others) much appreciated advice, I've enlarged the intake port (in the floor) and installed an air dam. This air dam will send air directly onto the lowest coils of the fridge.
I am also installing a wall approx. 1"-1½" distance from the coils. For safety, I covered the 'hot' side (the side facing the coils) with sheet metal.
The 2nd photo (floor vent for fridge) shows the original hole in the floor, which now reaches to (comes directly underneath) the coils & propane burner. And the flow of air is now channeled (as I mentioned) by an air dam.
The 1st photo ("holding tank vent behind fridge") is self-explanatory. But, as I said, no holes are cut yet. The negative slope disappears (the 'bend' is flex hose) once the top pipe is attached and fixed to the roof.
The 3rd photo (A/C vent into fridge chimney) is just that. Only it will now run up and behind the chimney (using flex hose) and channeled in at the very top, just below the exhaust vent.
Okay, clear as mud, I'm sure. When I get the wall installed, I'll update the photos... and thanks, Gus, for the email offer.
BTW, finally found some excellent venting diagrams (by Norcold) ... I'll try to insert the link. Hopefully, they'll help someone else as much as they've helped me.
Thanks to everyone; you guys are the greatest!
Nellie
Sorry -
Couldn't get that link inserted. I'll try again...
http://www.rvmobile.com/Tech/Trouble/vent.htm (http://www.rvmobile.com/Tech/Trouble/vent.htm)
Hope it works.
Nellie
Excellant link, Nellie. It shows everything SO MUCH BETTER than I could explain. . . I'm glad you found it!
Please forward those to ALL RV manufacturers and conversion companies, ok??? I can not BELIEVE I've seen as many fridges with improper installation as we have when working on factory rv's and conversions!
Sounds like you're moving forward in the right direction now. Christy Hicks
Nellie,
I think you have the situation well in hand now.
That link is essentially the same thing that is in my Norcold installation instructions. I had planned to email you copies if you didn't have them.
The AC vent may or may not help the frig vent draft, depends on its temp I guess. Anyway, it will be interesting to see what happens.
I firmly believe that you need to install a regular RV frig vent which is 24" x 5.25". This is the minimum size you will need for sure now that you are adding the AC vent also. The vent roof covers are low and smooth and designed to use airflow to aid the draft.
When you cut a hole this size you need to install a doubler which is a sort of frame around the hole about 1.5" wide. It is the same thickness and same metal as the roof metal and riveted. Pop rivets will do. It needs to be installed before you cut the hole, this keeps the metal around the hole from buckling and distorting when you cut the hole.
The vent frame may serve as a doubler but I don't think so. It has been too long since I did mine for me to remember for sure.
This doubler is important also because the roof skin is part of the structural strength of the bus body which is much like a walnut shell.
This is common practice on airplanes which have the same stressed skin.
I doubt the bus will fall apart if you don't install a doubler but it is a good idea!!
Gus -
You have been right on from the very start... and this from a guy who (at first) didn't even know a vent was required :)) I'll even install that 'doubler" thingy-do (I even have a riveter... God knows I need it :)).
And thanks to Christy and Sean (and a whole bunch of others) that have offered their time and guidance. As Howard (Roman) might say, "I'm an idiot." But with friends like you, I'm getting (slowly) smarter.
I'll keep you informed... whether you like it or not. :)
Nellie
Nellie,
When I got the bus in '06 I knew nothing about RVs or buses.
Thanks to this board and a bunch of digging I got it done. I hate to think what I would have done without this board and "the other one"!
We were all "idiots" at first, no sin in that.
Does my post back in page 2 make more comedic sense yet?
"Nellie, install that fridge properly and stop screwing around, "
I got no idea...
happy coaching!
buswarrior
Throwing in my experience with a 3-way. My refer does a good job over time with 120v and can do a great job (freeze everything...oops!) with propane. Going down the road I thought 12v would be useful to save propane but I was wrong. 12v is just not enough to keep the frig cool. I wound up keeping it on propane because it just worked better than the other modes. While in Las Vegas during 100 degree plus days even the propane struggled. My unit is an old Dometic manual type built in 1979. When it goes I have a good used 12v compressor type to go in it's place.
from BusWarrior
QuoteDoes my post back in page 2 make more comedic sense yet?
Hi BW - :)
Actually, it made sense back then... I just didn't get it. if you check page 3 you'll see my 'admission of ignorance' - always a bitter pill to swallow. :-[
BarnOwl: Thanks for sharing your BTDT info. Based on all I've heard, I'm going to 'quit screwing around' :-* and go strictly with 120VAC and (eventually) propane. But propane can wait until I get a larger 'chimney' (and some $$).
Still, after a year with no fridge at all, this feels like luxury! And I can keep using ice-packs for going down the road. Heck, until last week, that's
all I had. So you see, just like 'The Jeffersons,' I'm still... Movin' On Up. ;)
Nellie
Nellie,
You still need a chimney, even with only 120vAC, since the frig system uses a boiler no matter what the power source.
The chimney draft pulls in cool air to cool the two sets of coils, the upper coil being the one that removes heat from inside the frig.
The only real difference between AC and LP is that AC has no toxic exhaust gases, it just heats the boiler with a hot coil instead of a flame.
However, during cold weather it will operate well. I know because we did it for a while before we knew better. It did give off some nice heat into the bus though!
Hot weather is another story, I don't know how it will do then but my guess is not very well.
Nellie, the newer RV's with a slideout kitchen have the vent and the intake on the outside of the coach for the fridge they have nothing thru the roof if that would be easier for you
good luck