| Author | Message | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 154 Registered: 11-2006 Posted From: 75.3.203.214  Rating: N/A |
I want to ask for anyones advice on the pro's and cons of using either a 12 or a 24 volt refridgerator. I assume the 24 volt will be colder, but I don't like making assumpions. My 12 volt just does not keep the food cold between camp sites with hook ups. My 2 start battery, 24 volt power I assume could be used for power on the road and 120 volt while at a camp site hook up. I realy do appreciate all of the advice I get on this board. Roger (Message edited by roger on February 09, 2010) | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 788 Registered: 3-2007 Posted From: 71.53.153.91  Rating: N/A |
Roger; For starters, does your refer have 24 volt hook-up? Some have 12 volts and 120 and gas. Others have 24 v,120volts and gas. If you can hook it up for 24 volts it may do better. It may be wired for 24 volts and if you run it on12 volts it will not work properly. Does it work on 120 volts? If not you have other problems. What type of refer is it and get the make, model and lets go from there. Gomer | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 155 Registered: 11-2006 Posted From: 75.3.203.214 Rating: N/A |
Thanks Gomer, I will get that info tomorrow. Roger | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1046 Registered: 7-2006 Posted From: 74.162.77.220  Rating: N/A |
Roger - If you're using a standard RV refrigerator, with 12/120 and gas, the 12 volt is just for maintaining the "coolness", and not for getting things cold. That is... it'll try to keep things as cool as it can, if you don't open the door, and if what's inside is already cold as all hell. Even then, they make no promises! You would be better off getting a decent inverter, and running the fridge on 120 from your present 12v supply (if that's what you're using?), or from a 24vdc supply. Ahh... of course, all that is IF you're using an RV fridge. | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 179 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
I use a Norcold 6.3 cu ft "marine" refer that has a comperssor that runs on either 12v (can be 24v) and 120vac. It is not affected by being out of level and runs well in any weather. Pulls about 5 amps at 12vdc. Good Luck, TomC | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 492 Registered: 10-2003 Posted From: 74.251.162.133  Rating: N/A |
It should probably be clarified that the voltage has nothing to do with the cooling capacity but does affect the amp draw. A compresor running on 24 volts will draw less amps than the equivilent 12 volt compresor. Don't expect to wire a 12 volt compressor with 24 volts to up the capacity you will just burn something out | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1082 Registered: 11-2005 Posted From: 173.202.22.253  Rating: N/A |
If he has a standard absorption type RV frig he has no compressor, they operate from a boiler heated by DC, AC or LP. I presume 12 or 24v will run a compressor well but with pretty high amps. However, it will not run the RV absorption type well. | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 493 Registered: 10-2003 Posted From: 74.251.162.133 Rating: N/A |
Good point Gus I am used to the marine units that are just 110AC/12VDC | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 156 Registered: 11-2006 Posted From: 75.3.203.214 Rating: N/A |
OK Guys My refridgerator is a regular RV type made by Domestic it is a 12 volt DC, 120 Volt AC AND GAS. The manual does NOT say anything about being able to run it on 24 volts DC. I do not have any gas on board. It was either never installed or removed before I bought it. I don't really like gas on my RV anyway. It is like John says, it does a very poor job of keeping any food cold. Also the 120 AC does not do a good job of keeping the food cold either. My question then is what is the best way to go. get a new 24 volt unit or is there someing I can do with this one to make it do a lot better. I do have a good inverter. 24 volt, 4000 watt unit. I am in the process of installing for the roof air conditioners. 13,500 btu. I really do appreichiate all of your advice . Roger | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 790 Registered: 3-2007 Posted From: 71.53.153.91 Rating: N/A |
Roger; Thanks for the info. You have answered a couple of questions already. Since the 120 v doesn't do the job either you have a problem with the unit itself. But before you go and buy another unit,try this method. Take the unit out of the wall, not necessary to take out of the coach. Turn the unit upside down for 24 hours, then lay on one side 4hrs,other side 4hrs then flat on its back for 2 hrs. set the unit upright and all the time listen to the sound of gurgling in the cooling unit on the back. These units have amonia/water and that is what transfers the heat inside to the outside of the box. OH I hope you have a vent for the heat to get out from behind the refer. If not that will probably be your problem to start with. It will get HOT and if it can't get out it won't work right at all. I hope I have helped you and if not,we will try another approach. Check the venting first!!! Gomer | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1047 Registered: 7-2006 Posted From: 74.162.77.220 Rating: |
Roger - The RV refrigerators work best on gas, and 2nd best on 120vac. Mounting a small 25lb bottle in a bay just for the fridge, could be a very viable option to you, and fairly easy as well. You'll still need a 12vdc supply for the igniter and controller, though. Running it on 12vdc, just isn't a realistic option for that type of fridge. And using an inverter to use the 120vac ability of the fridge may work, but not that well. The fridge works by heating the chemical inside the cooling coils you see at the back of that thing. The heating element and burner is usually on the right side (facing it from the back). Heating it using gas is the most economical way of making it work best. Heating it using 120vac, uses a helluva lot of AC power; it's like a big frikkin' heat coil around the gas-filled piping. It works OK, but uses more power to keep the food cold, than if you ran a compressor type of cooling unit. The bottom line? If you really hate to use propane, even a small bottle of it, then it'd be better to buy a compressor type fridge. They ones designed for 12 or 24vdc are more expensive than ones for 120vac, harder to find, and/or get repaired, and you can't always get one that's the size you need for the money you have.....but they work as well. The standard apartment size 120vac fridge is cheap, you can toss it and buy a new one for less than it cost to repair the other types, and you can find them all over the place. The only down side? You'll need to make sure it gets the 120vac it needs, 24/7/365. That means a battery bank ($$$), and charging circuit, along with a 2nd inverter ($$) for the fridge alone. (Harbor Freight sells a 2,000/4,000w peak inverter for under $150) (Best Buy has 9cf fridge under $200) (NAPA for deep cycle batteries $$$$) Personally, I'd go with a gas-grill size bottle of propane, and use the RV type you already have. Every commercial RV uses gas, one way or the other... It ain't all that bad. PS: Gomer posted as I was typing, and makes a great point! Check the venting and make sure there's no restrictions, but 12vdc ain't gonna' do it no-how, anyway. (Message edited by john_mc9 on February 10, 2010) | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1849 Registered: 10-2003 Posted From: 71.58.71.157  Rating: N/A |
If you don't want to use propane, Norcold makes a 12volt-110volt refer that doesn't use propane and works pretty decent with good ventilation up the back. Not as good as a propane unit though when it gets really hot out. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1083 Registered: 11-2005 Posted From: 173.202.43.145 Rating: N/A |
As Gomer says, if it doesn't work well on AC you have another problem. After you do the upside down thing check your installation manual for proper vent chimney construction, these small clearances around the coils are very important. LP is a great system, it is even better for water heating - much faster. Electric water heaters are huge power users. My guess is that 99% percent of the big SS running down the road use LP. I always use AC to cool it down before a trip then switch to LP. Unless my frig is almost empty it doesn't use a lot of AC power once it is cold. I agree that LP is the best and use it always when under way. 20lb LP bottles are cheap, around $26 at HD. I have two installed for the frig and water heater. One bottle lasts about two weeks when I have no AC hookup. 20lb bottles are small enough to be easily carried for refill. I got tired of trying to find a refill place I could get the bus into when I had a large permanent tank. | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 157 Registered: 11-2006 Posted From: 75.3.203.214 Rating: N/A |
Thanks for all of the advice, it sure helps me out a lot. I will let you all know how the upside down thing works when I get a chance to doit. Thanks again, Roger | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1048 Registered: 7-2006 Posted From: 74.162.77.220 Rating: N/A |
Roger - I don't know how well you like electrical circuits, but before you yank the fridge out.... It could be a bad thermostat that's keeping it from running right... and/or insufficient 12vdc to the control module in the fridge. You can isolate the problem by locating the AC wires that feed the heat coil in the "chimney" on the right side of the back of the fridge. Once you locate those wires, and disconnect them from the control board, you want to feed 110vac directly to them . MAKE SURE YOU LOCATED THE RIGHT WIRES. The 12vdc heat coil is in there also, you DO NOT want to feed that 110vac, needless to say. That's how they check it in the shop. They run 110vac directly to the heat coil and let it sit for a few hours. If it cools, you know it's the thermostat, weak 12vdc supply, or bad module... But at least you've ruled out the cooling assy. It's usually the thermostat. The things get corroded from the moisture and sitting for long periods without use. Go here: http://www.rvmobile.com/ and look at the Technical Help page. They give decent instructions for free!! Good luck! | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1112 Registered: 7-2006 Posted From: 75.208.242.186 Rating: N/A |
Yup....good post, JTNG...!  RCB | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 6 Registered: 1-2009 Posted From: 166.183.207.144 Rating: N/A |
Because of an interest in full-time Coach life & just out of curiosity....how many here do run a dedicated inverter & an apartment sized refer? ....How many batteries would it take to keep it alive (based on minimum usage ) for 24 hours? Would a bank of say 10 large car sized units keep things cool for a week? | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1116 Registered: 7-2006 Posted From: 75.210.23.248 Rating: N/A |
We have 5 house batts...group 27 Marine deep cycle. Run a 11.5 CU.FT. Maytag , 2door Fridge, (2000 Trace Inverter). No problems in the 4-5 year life of the batteries. (They are charged also by a 10 watt solar panel). Typical day....Run Generator mornings and evenings, 1.5 to 2 hours(each end)...on general purposes. (Microwave, TV, radio, fans, lights, etc all draw down) FWIW | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1082 Registered: 10-2006 Posted From: 66.82.9.62  Rating: N/A |
Would a bank of say 10 large car sized units keep things cool for a week? No way. Not even 10 deep cycles . Depending on the price you pay for the fridge will determine the efficiency. A few hundred bucks at Sears will get a unit with a tag that tells you the yearly power consumption in KW. From there a hand computer will give the daily consumption. Frequently the unit will require over 100A of 12V in 24 hours, requiring 200A battery per day. 10 days would be 2000 lbs of batteries , with a relativly short service life as there sitting discharged (MUCH UNGOOD) for 10 days . a Sunfrost could reduce the consumption by over 1/2 , but its a really expensive product , big (good insulation) and heavy. For camping "forever" with out a noisemaker to feed, hear and repair , Propane is the campers delight. Our unit on a boat is over 50!!! years old and still keeping ice cream like a rock. FF | ||
| Jerry W Campbell (Jerry_w_campbell)
Registered Member Username: Jerry_w_campbell Post Number: 31 Registered: 7-2005 Posted From: 66.82.162.19  Rating: N/A |
I have a 10 cf refer/freezer it draws 1.8 amps at 120 volts. At 12 volts, it draws about 150 amps per day. I have about 1000 lbs (1600 amps at 12 volts) of batteries. I have 800 amps to use, that means the refer would last about a week if you didn't open the door. It would not be good for your batteries to do that often. Then there's the 900 amps you need to replace the 800 amps to refill the batteries. That's a lot of amps. Batteries need to be fully charged every few days at least and preferably every day to last. 1000 lbs of lead acid is not cheap. I don't run a dedicated inverter, Everything runs off a 3000 s/w inverter. Jerry | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 18 Registered: 11-2008 Posted From: 141.156.33.61 Rating: N/A |
Running a propane fridge on electricity is less efficient than running a compressor type. My 8 CF Dometic uses 5 KW on a hot day running on 120 AC. It runs about a week on 20 pounds of propane in the summer. It is cheaper to use AC power at present rates of 15-25 cents per KW when you can plug in, running on batteries or a generator is tough. Compressor type fridges use less electricity than the electric option on a propane fridge. A genuine DC compressor fridge is the most efficient and expensive. A home style fridge and inverter is a good compromise for price. For boondocking without a big investment in solar, batteries and inverter, propane is great. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1084 Registered: 10-2006 Posted From: 66.82.162.13 Rating: N/A |
"It runs about a week on 20 pounds of propane in the summer." I would check the flame color , clean the heat tubing (special brush) and the door gaskets. A 20lb bottle should run 3-4 weeks on a really old unit , and half that on something from this era. Check the external venting too, a restriction, less venting than the factory folks require, is a big no -no. FF | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 19 Registered: 11-2008 Posted From: 141.156.168.157 Rating: N/A |
You're right, I converted incorrectly, don't trust everything you read on the internet. I have an 80 gallon tank. Sorry for the misinformation. | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 2 Registered: 2-2010 Posted From: 99.39.13.50 Rating: N/A |
Lets look at numbers for a minute, which will help decide. A GALLON of propane weighs about 4 1/4 POUNDS, and contains 94,600 BTU, most appliances are about 80% efficient, so you will get about 75,000 BTU net. Electric heat produces 3,412 BTU per Kilowatt, so you would need about 23 Kilowatts to produce the same heat as a gallon of propane. At 12 volts, thats 1917 AMPS! Jerry's comment about his refrigerator using 1.8 amps of 120 VAC means it will take about 20 amps of 12VDC to run it thru an inverter. That translates to a LOT of amp-hours! The amp-hours don't recharge quickly, and cycling a battery bank a lot wears it out. So, in my opinion, propane for boondocking refrigeration (and cooking/water heating) is a clear cut winner, aside from the fact that the tank is much smaller and lighter than the number of batteries required to do the same work, recharges in minutes, and doesn't wear out. G | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 7 Registered: 1-2009 Posted From: 166.128.138.199 Rating: N/A |
WHEW! As I have come to expect from the members here, THAT was a detailed & in-depth response! Thanks for the effort you people put forth, there are few places on the Net where you can trust what you read.....and this is one of them..thanks Ian, for you efforts at keeping this place a GREAT site. My query was based on my present situation, working at getting this 4106 in shape to hit the road this Spring for a LONG solo F/T coach experience. I was very lucky to be the recipient of 10 gel-cell batteries removed from service after 1 year of "emergency back-up "duty a couple of days before I bought an aluminum slider-rack that hold exactly 10 batteries! I have hooked them together with solid copper bus-bars and built an aluminum housing to cover the whole arrangement & make it air tite (save for the venting to the belly of the coach). This "batteryBox" set across the rear of the rear baggage compartment, as if it were an extension of the original bus battery box, for service the drawer the batteries set it unlocks and slides out the passenger side of the coach. I would really like to be able to sit in one place for at least a couple of days without running the Generator and I expect that most of the time I will be "shore-powered" while at rest but not ALL of the time(s). FWIW I will also be carrying 6- 20 lb. Propane tanks, in the forward baggage bay, secured to the fwd. bulkhead & boxed as well. These are to be hooked up to a manifold for ease in use and refilling. My gen set is a 6000w Propane/gasoline Onan unit. My plan was to use a new Apt. sized refer that is already in my hands. And BTW this is a one man road show, so my electrical usage will be light, computer, LED lights and the refer will be my biggest consistent draws. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1119 Registered: 7-2006 Posted From: 75.229.11.67 Rating: N/A |
Sounds like a plan, Jack...best wishes! Assuming your fridge is in good shape, from my experience, it should be very do-able. BTW...any way to post a pic of your propane setup? (manifold included....) RCB | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1091 Registered: 11-2005 Posted From: 173.202.34.124 Rating: N/A |
I'm always surprised at the frequent postings about being afraid of LP. I don't remember even one posting of a fire or explosion originating from LP. However, if there is a fire and LP bottles are in the fire there is no doubt there will be an impressive fire/explosion soon to follow! LP smells so bad it is hard to ignore a leak anywhere and it is very efficient in RV friges and water heaters. It also does a great job heating my 4104 via two small Buddy portable LP heaters. I can't picture owning a bus without it. | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 252 Registered: 1-2007 Posted From: 208.81.157.234  Rating: N/A |
Jack, what is the capacity of the batteries? There are several things you can do to get better service out of your refer. 1. Add insulation to the box on sides and top without blocking air circulation. 2. If the condensing coils are separate on the back and you can unbolt them and gently bend them out and build extensions for the mounts, then add insulation to the back of the box. You must not restricting air flow. If the condenser is on the bottom add insulation to the back, again without restricting air flow. 3. Turn off the anti-sweat heater in the cabinet if it has one. 4. Defeat the defrost system if it has one. Use a switch so you can turn it on when plugged in or running genset. Easy if it has the old style defrost clock, more involved if electronic defrost. If you run for a long time without defrost, depending on humidity, how good the door seal is, how often you open the refer, and it stops cooling well you may have to manually defrost. | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 8 Registered: 1-2009 Posted From: 32.176.197.74 Rating: N/A |
The batteries are 90 amp hour running 20 Ft. thru #02 cable. R.C. ....the pic will come in time but for now too much STUFF bars easy access. The Manifold was easy,copper pigtails from each bottle connected to a mainline with a valve at the end. The plan is to open a single bottle at a time in order to monitor consumption. AND... Thanks to the rest of you who offered their experiences &/or ideas, all were worthy of contemplation. | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 8 Registered: 2-2010 Posted From: 99.39.13.50 Rating: |
Jack, I hate to jump on a newbie, but you have done two dangerous things! 1. Lead-acid (or wet) batteries produce hydrogen when being charged or discharged. Hydrogen is lighter than air, and EXTREMELY FLAMMABLE! Your "air tight bottom-only vented" battery box will fill with hydrogen, and when one little static spark occurs, your bus will become the Hindenburg! Battery boxes must be well vented on at least two sides, or top and bottom. 2. Propane cylinders are only filled to 86% of capacity to allow for expansion. The dip tube is installed to the proper length to show liquid when the tank is 86% full. Filling multiple tanks thru a manifold may well fill some completely before liquid shows on the one you are looking at. That won't leave enough expansion room for all the tanks, resulting in the pressure relief valve opening on one of the tanks, on the first warm day. No big deal until the relieved gas gets to an ignition source, then see item #1! Propane is heavier than air, the tank(s) must be well vented below. Sorry, G (Message edited by George_todd on February 17, 2010) | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 9 Registered: 1-2009 Posted From: 32.176.197.74 Rating: N/A |
Hey George, good points! I was planning on parking next to you in the future and inviting you over to see my handiwork after supper by candlelight....so I suppose that's out of the question now eh? Actually the batteries are sealed (in that I cannot add fluid) and I do have vents, into the 8-D battery stack on the hi side and thru the bulkhead near the door just inside the rear tires on the entry side. These vents BTW came via a local aircraft mfgr. & are narrow oval in shape & 1'X3.5" & are designed for bulkhead penetration, needles to say, they are aluminum. I am trying really hard to maintain the "all aluminum" integrity by using it in place of wood & plastic where ever possible. As for the propane, there is a vent to the outside on each end. The tanks will be individually secured to the forward B/H with chain and the tanks will be filled after they have been removed not thru the manifold, which is for discharge only. You not being afraid to JUMP ON THE NEWBIE is not only justifiable it is just being plain responsible....you done the right thing Bud! Now if you'd just advise me on how to collect that Hydrogen, meter it and feed it to the intake for a little boost when climbin' them hills? (rolleyes here) | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 800 Registered: 3-2007 Posted From: 71.53.153.91 Rating: N/A |
Newbie be starting problems!! Settle down and relax. Gomer | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1055 Registered: 7-2006 Posted From: 74.162.75.62 Rating: N/A |
Go Newbie! (btw... George is new, too!) | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1123 Registered: 7-2006 Posted From: 75.210.148.38 Rating: N/A |
Goood Grieff.... JTNG,...youse must be a'doin' awright!! Still prayin' for ya! RCB | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 934 Registered: 7-1997 Posted From: 99.39.13.50 Rating: N/A |
I sure hope so too! GTOG | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1057 Registered: 7-2006 Posted From: 74.162.75.62 Rating: N/A |
Thanks guys. I really didn't expect to still be here by now.... After all, it's been over three years since... So RC.... I guess maybe your "stuff" is working, huh? I hope? Good to seeya' back George! I really missed (YAWN) the great (YAWN) dialog....the well presented expla(yawn)nations, and the detailing of al l t h i n gs impor zzzzzzz Sincerest Thanks. | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 10 Registered: 1-2009 Posted From: 32.176.70.210 Rating: N/A |
John, do you have a carbon monoxide detector, you seem to be a bit more drowsy than usual....just sayin Bud... ;) | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1059 Registered: 7-2006 Posted From: 74.162.75.62 Rating: N/A |
Need a G.T. detector, Jack! | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1125 Registered: 7-2006 Posted From: 75.210.199.172 Rating: N/A |
John...we are glad....amazed...that such a...well...let's just leave it there...... We are glad!!!! RCB |
