| Author |
Message |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 3:42 am: | |
Is anyone out there using a home refer in thier bus? if so how much power does it draw and what kind of battery bank do you have???
I am considering two under counter units (freezer/refer) which are "energy star" rated and together cost half of what a much smaller propane unit costs. I suppose if it were that easy everyone would be doing it.
Chris |
FAST FRED (4.245.191.211)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 5:49 am: | |
Many folks use home reefers , but before purchase of anything the concept is to figure the conversion requirements that YOU need.
Will you be at the Power Post (PP)almost all the time?
Will you try for silent living?
Are you "fulltime" so need differennt requirements from the month or two vacation folks?
Do you live / travel in some Hellish areas that need 24/7 max air cond?
Or go Skiing for the winter?
How long do you wish to boondock , days, weeks ,or months?
When you have figured YOUR needs , its fairly EZ to figure what the coach would be fitted with to perform YOUR service with comfort & style.
For the house fridge read the manditory EPA tag that shows how much electric is used in a year.
Divide by 365, and you will have the KW (usually about 1 ) needed per day to keep it running.
A KW is volts times running amps , so 1000 (a KW)divided by 12V is 83A that will come out of a bat bank every 24 hours.
With the inefficency of most inverters at creating electric and the poor performance of some induction motors on home made 120V , best to figure 100A per day.
That translates to one 200A bat set (at 20 hour rate) to keep the fridge cold , and the bat set above 50% discharge for long bat life.
How many days before moving on , or running the genset/noisemaker to recharge the batts ?
Remember this 200A bat will only service the house fridge fore a single day, and you still need a FW pump, lights TV , radio fan ECT...
Decide your requirements , then select the right gear to do it.
Basically the boondockers usually choose Propane, the PP folks go with house stuff.
Your Way?
FAST FRED |
bobm (68.35.160.48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 9:47 am: | |
I have a side by side house unit. At the top of the freezer I have a five gallon aluminum tank with a mix of non toxic anti-freeze that freezes at about zero degrees. Inside the tank is a coil of copper tubing to circulate the house a/c refrigerant. I also have a small 12v fan to blow from the freezer into the refrigerator. When frozen it will last 60 to 80 hours depending on ambient temp and how often door is left open |
James Maxwell (Jmaxwell) (66.81.215.171)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 11:31 am: | |
I have a GE 11.7 cu/ft. Pulls 1 amp @115v approx. 17 minutes of the hour (depending on loading). Sanyo makes a similar unit, also E-Wave. 508ah AGM battery bank and a 500watt solar panel bank. My living rm. tv pulls more--235watts. IMHO, whichever home unit u may choose, it will beat a Dometic or Norcold hands down! SunPower, and a couple other high effeciency low-voltage types are also nice, but bulky for the capacity and very pricey. |
H3Jim (68.107.62.94)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 11:42 am: | |
Fred,
Very nice summation, and even better, it's now in the archives. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 12:07 pm: | |
Yes perhaps I was a little vague..
I plan several long trips a year (1 month) and as many weekends as possible.
I do would like to boondock 99% of the time and would rather not listen to the Genset.
I will build the battery bank accordingly.
Mr.Maxwell, I am interested in the details of your solar array, care to share? Also I lived some time on a boat and fould a 19" LCD computer monitor which doubled as a TV (built in tuner and cable input for DVD/VRC/etc), the dray on this monitior was so low that I bought another and put in in a Land Rover / Mobile film unit as a playback display. I believe it cost around $500, probably less now. This might save the 235W you are now using.
Bobm, could you be more specific as to the functioning of your system, sounds interesting. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 1:02 pm: | |
Honda wattage calculator at
http://www.hondapowerequipment.com/genwat.htm
Just for info.
Chris |
gabby (4.246.93.175)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 12:10 am: | |
I have a 15cf frig that is supposed to use 375 kw a year. That is just over 1 kw a day. I have 2 150 watt solar panels at 24 volts. The other day I started the frig at nitefall on landline voltage. The next morning I switched to inverter power. I have a 3600 watt trace inverter. The solar kept the frig running for 3 full days. I probably lost some battery every day but the voltage never got below 25.4 volts. I am satisfied with the system that I installed and will check it out again on a trip this weekend. |
niles (4.4.112.82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 12:41 am: | |
Bobm,
what an innovative idea - the knowledge and talent of bus nuts never ceases to amaze me - keeps me tuned in - thanks
niles |
James Maxwell (Jmaxwell) (66.81.214.146)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 12:59 am: | |
Chris: I already have an LCD monitor; that's the one that draws 235 watts. 30" Zenith. The 18" LCD in the bedroom only draws 55 watts. Only consolation is that the 30" LCD pulls a lot less power than a similar size Plasma (abt. 375)
To the solar. Know from the outset that I am no proponent of solar for reasons that I could preach abt. all day. And I'm still wondering why the hell I went out and bought 2 more panels to double my array when I was dis-satisfied with the 250 watt system. I like to console my idiocy by saying that I spent $1200 to demonstrate that solar wasn't worth a damn and then spent another $1200 to prove it.
I have 4 Kyocera 125 watt, 12v panels hooked up ser/par for a 24 volt system, controlled by a Trace C35 controller, feeding 8 12v 127ah deep cycle,AGM batteries,2 parallel banks of 4 in series for 24v. All wiring is oversized for capacity and the panels are flat mounted on the roof, approx. 5' lead to solar controller and 8' to battery input from there. Mathematically, I have 14.2 available amps of output at 24v (each cell being 7.1 amps). However, I have never seen more than 8! Maybe there is something wrong or not working correctly, maybe even a bad cell, although all tested fine when I installed them. At any rate, I have a 7kw Diesel genset that will outproduce them in about 30 minutes, and AGM batteries don't really care how many amps you stuff into them at once, so I suppose I just keep the solar as a demonstration project on how to best waste your money. |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 1:44 am: | |
Mr.Maxwell,
Which batteries would you suggest? I have seen just about every possibly although both you and Sean (Neoplan Starliner) use the AGM cells and I am not familiar with them. I can get 8D1400 cells for about $100.00 each (wholesale), all my boat friends recommend Deep Cycle and the solar nuts seem to use 6vdc Trojans??????
I have had several Porpane refers and had problems with all. If they were not completely level they did not work well, if the sun hit the wall of the motorhome where the access panel was, they did not work well, and frankly when they were working properly, they were barely sufficient. Cheese did not spoil but the beverages were tepid. If I can use a domestic unit I would really like to. Also I am trying to keep as many windows as possible and would like everything built below window level, hence the desire for an under counter unit..Lastly for what I would pay to a propane unit the size of a shoe box, I could buy two top of the line undercounter units, one freezer, one refer, in stainless steel!
Gabby..
How long would the refer have run just off the batteries? What I am getting at is that without knowing how long just the batteries will run it for, I have no comparrison as to the effectiveness of the panels. If the batts alone last 2.5 days and the panels only strech it to 3 then there is a net gain of only .5 days from the addition of the panels.
Care to do the test and share the results?
chris |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 1:48 am: | |
Mr.Maxwell - just read your reply to the 6v vs 12v question so please disregard it here.Thank you |
FAST FRED (4.245.128.171)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 5:28 am: | |
"I have had several Porpane refers and had problems with all. If they were not completely level they did not work well".
This was a common problem back in the 70's , when folkes didnt bother to get too level.
The mfg have long ago fixed the problem , and now if you dont fall out of bed there fine.
Without exception every "poor" cool I have ever seen was from the instalation instructions being too much bother and NOT being followed.
Install them by Da Book , and they work just fine.
YES you NEED that damn big hole and funky roof cap, as well as boxing the flue.
My own coach preference for a coach would be a Survelle , made by dometic.With RV instalation instructions followed for the home unit.
This has much more insulation than the RV model , NO ELECTRIC CONTROLLS!! and can be operated from the front gas only. (Same as my 1965 unit on my boat).
For serious boondockin a propane stove , fridge and heater demands the least from the bat set (if anything) and will give the longest endurance, with silent operation.
FAST FRED |
James Maxwell (Jmaxwell) (66.81.63.138)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 2:50 pm: | |
To be honest, I have only recently put the AGM's into service, so I have to reserve judgement until I see how they perform over the long term, perhaps a year from now. I am impressed by the no maintenance requirements, no explosive gases being released, very minimal corrosion possibilities, and having used brass bus bars to inter-connect them, the neatness of installation. Bus bars can be a challenge with flooded cell batteries as there is always the need for cell checking; not so with AGMs. I bought used cell tower take-outs, all testing very good, and got them cheap, so you might consider it an experiment. However, at the price I got them for, I would not be disappointed if I had to replace them annually, providing the price stayed relatively stable. New ones are very expensive.
I don't argue w/FF premise of propane for people that primarily boondock; it is the most feasible means for them, however, it is a trade-off of optimum performance, since absorbtion refrigeration is not all that great, never has been, and never will be. Absorbtion systems are fraught with inherant proplems, they are expensive to build, and only work under very controlled conditions. I use to work on systems that had accumulators that are larger than todays buses! 10,000-20,000 TONS of refrigeration, and they were a nightmare to the owners: but a goldmine to pipe-fitters. Even the small 2-10 ton Arkla-Servelle units, popular 40 years ago, died as a result of inherant problems that rendered them as inefficient for size and fraught with more problems than they were worth. Again, owner's nightmare, mechanics goldmine. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 6:36 pm: | |
OK here's the system I am considering..
8 to 10 Interstate USRM-8D Cells
455 rm @ 25A
318ah
255 20hr
127lbs ea
$110.00 ea
Trace SW4024 Inverter etc.
One FF6SSTB Summit refer rated at 360KW per year
One FFS62 matching freezer rated at 360KW per year
Together these need about 200A per day by my math
Alternator 270AMP unit on coach
Generator 6.5KW Honda gasoline unit converted to Propane.
The other draws will be normal for a bus, a few low watt lights, 2 19" LCD monitors as TV's (only will run one at a time and rarely most likely), a water pump, small stereo.
Any opinions??? |
Peter Broadribb (Madbrit) (67.136.100.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 9:04 pm: | |
Chris,
Better check whether your 6.5kw Honda will still output that amount when on propane. Normally the propane versions have a lower output than their gasoline brothers.
So are you originally from Engand or it is just a coincidence that there is another Chris Goodwin who does motorsport in Europe.
Peter. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 9:22 pm: | |
Just coincidence, there is also a Chris Goodwin who does acrhiology in Virginia, another Chris Goodwin who wrote for some of the same magazines I did when living in London and funnily enough we all met responding to a page at Heathrow!
I lived in London for 5 years (until about 2 years ago) where I worked as an underwater camer specialist on feature films and commercials and as a stills and video cameraman on expeditions for several companies including Nat Geo and Discovery. I did photography and wrote for BBC Wildlife, Geographical and a bunch of lesser publications. You can see some of my photos at an old site at www.nomadiceye.com
Came back stateside after 12 years because both my parents were in ill health, met up with an old girlfriend and decided to stay, I continued to live half the time in London and work, mostly in Africa. Eventually we decided to have a child, I moved back here full time and opened a business and I now have a beautiful 14 month old daughter.
I tried to get my wife to go camping and hiking but she thinks it is pointless to work all year only to pretend to be homeless while traveling. I can't do the Hotel thing (I would rather stay home) and she will not camp, so...I bought a 27 foot motorhome, packed her in and drove two winters ago to Cabo San Lucas mexico and back camping on the beach each day. By the end of the trip she was sold and after things settled with the new baby, I decided to build a bus and drop the motorhome off a cliff where it belongs.
There you go, more than you asked, but a fraction of the story.
Chris
PS I will check on the output, not sure how but I will give it a try. |
r.c.bishop (128.123.221.225)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 12:05 am: | |
Interesting story, Chris! Thanx for sharing.
RCB
64'Crown Supercoach (hwc) |
James Maxwell (Jmaxwell) (66.81.53.47)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 12:10 am: | |
Seems that I have read on one of these boards that the down-rating is in the neighborhood of 15% but not certain of that, since I've slept since I read it. |
Tom Caffrey (Pvcces) (65.74.65.65)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 1:39 am: | |
Chris, the output derating may not matter much because of the SW4024. It can make up surges that are over the limits of your generator, if needed.
The main thing that could meddle with you that I can think of is propane supply.
You probably will want a liquid delivery to the generator, but vapor for most other needs and your tank will need to be quite large to serve you well.
For what it's worth.
Tom Caffrey PD4104-2576
Suncatcher |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 4:13 am: | |
Liquid propane to the generator? Propane is only a liquid under extreme pressure or at very low temperatures if I remember my gasses properly?
Chris |
Peter Broadribb (Madbrit) (67.136.100.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 4:56 am: | |
Chris,
Thanks for the resume, seems you have had a very interesting life so far.
Some propane appliances do run liquid right to them and then have an evaporator, like a carburettor, where it turns to vapor.
Peter. |
madbrit (67.136.100.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 4:58 am: | |
Perhaps I should not have said appliances to avoid confusion, I should have said equipment such as engines may use the liquid propane.
Peter. |
Bulldogie (69.4.194.126)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 8:09 am: | |
Chris, We had a stick motor home with a propane generator, hated the dam thing, the manufacture had put the liquid exchanger in upside down and because Propane people are required to put the stinky in the propane that means you get a oil residue that builds up in the exchanger. The liquid is required because you would need a tube the size of your wrist to get enough gaseous propane to run the gen set. The other problem with propane is that the gen set eats it up like nobody's business and unless you have a humgous size tank, we had a big one but it only lasted for about 3 days during the summer when the gen set needs to run to keep the air running. Some say that propane is better because it does not smell as bad or have the fumes but then if you vent out the top you don't have that problem and you have lots of fuel on most busses, and you can always go in your toad and get more. IMHO Also you might want to go to your closest RV wrecker establisment and ask them what causes most of the motor home fires. Propane was the most with fuel problems in the engine compartment a close second, so we won't be having any propane on our bus conversion JTWWWTDI (just the way we want to do it) hehehe |
David & Lorna Schinske (Davidschinske) (67.216.90.61)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2004 - 11:16 am: | |
Sunfrost makes a pretty good ref/fzr (RF19 model = 2 Danfoss compressors - 1 ref & 1 fzr that adds up to 8 cf per compartment). It is very efficent (sold to the solar powered folks) and is available in 12vdc and 120vac. The price is a little less than those fancy RV fridges with tiny freezers. I need freezer space for my pizzas and all the Schwan's food we buy!!
Lorna |
Lorin David McCleary (Wacoastmci) (148.78.243.122)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 10, 2004 - 9:50 pm: | |
Anyone have experience with NovaKool refers? Used in boats. They use Danfos compressor and are 12v/24v and 110v. They have a model which is dimensionally a replacement for our miserable Norcold so chainsaw mods to cabinet not required. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 15, 2004 - 11:29 pm: | |
Some interesting refrigerator links:
http://www.backwoodssolar.com/Catalogpages2/refriger2.htm
Learned that gas/electric refers use loads of juice when running on elec as the pump must work almost full time due to the design of the system...So much for the 3 way unit if you ever want to run of batteries when parked...
I have read that effeciency can be doubled by adding insulation and adding ventilation around the coils and am going to try this with the small refer in my shop and will later post the results...does anyone know how I can measure the KWH it is using now and will use after mods?????
Chris |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 16, 2004 - 12:20 am: | |
Danfoss now makes 12 and 24 vdc compressors for refers....retrofit anyone??
http://www.danfoss.com/compressors/products/r134a_12-24v_dc/index.htm |
FAST FRED (4.245.212.108)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 16, 2004 - 5:04 am: | |
"...So much for the 3 way unit if you ever want to run of batteries when parked..."
The 3 way systems were designed to cut propane use while the unit is under engine power. and to keep cooling while a gasolene powered RV is fueling.(NO open flame).
Not a very usefull option in diesel coaches , where there is little contact with gasolene pumps.
Propane fridges use so little that the option of a propane ONLY (and no circuit boards) seems to work very well for campers.A "little" is 1/3 to 1/2 pound a day in RV sizes , although HUGE house units are avilable.
The PP folks CAN use the 120V option to cut the miniscule propane use , but a new fridge should have a Dinasour board installed , after the unit operates a week or so.
Or just look for a used early mechanical relight unit & forget "automatic lighting".
Works for me,
FAST FRED |
ChuckMC9 (Chucks) (66.167.142.166)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 16, 2004 - 12:34 pm: | |
Chris: "does anyone know how I can measure the KWH it is using now and will use after mods?????"
I recently got one of these thanks to a tip on the boards:
Kill A Watt electricity / energy usage monitor / meter
It's a quick & easy little gadget. No substitute for a real power management system, but for brain-cramp-free measuring it wrks great. |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 16, 2004 - 9:26 pm: | |
Chuck - thanks! Just bought one!
Chris |
Robert Wood (Bobwoodsocal) (4.63.41.14)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 17, 2004 - 7:54 pm: | |
That is cool- I had to get one too. Thanks Chuck! Bob |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 17, 2004 - 11:35 pm: | |
Still looking into increasing effeciency and found an article at http://hem.dis.anl.gov/eehem/93/930306.html The long and short of it is that Samsung added 1" of insulation to otherwise unmodified refers and saw a 26% gain in efficiency... Imagine if you put 2 additional inches of insulation on AND used small solar fans to cool the condensor coils which were moved away and insulated from the refer itself?
The refer in my home is in a wall cabinet with an overhead cupboard only 2" above it's top, just on a thought I placed a inside/outside thermometer in the kitchen, one probe laying on top the refer in the vent area, the other in the kitchen...Today my kitchen reached 79f while the area above the refer was at 110f ! I could just about heat the house with all that heat LOL, seriously though if it is using better than 1kw per day, that energy is going somewhere...converted into heat I assume and as the refer is surrounded on 5 of its 6 sides with falls, cabinets and floor, it is basically sitting in a heat trap fueled by its own efforts to cool the interior...Not too bright it seems.
Chris |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 17, 2004 - 11:51 pm: | |
another interesting find... How about an electric refer that has these specs:
14 - 17 Amp-hr/day on 12vdc...
Too good to be true?
http://vegastrailer.com/sundanzer/Specifications.html
Chris |
FAST FRED (4.245.230.34)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 18, 2004 - 5:31 am: | |
To get rid of the fridge heat ,
a propane roof cap , and copying the instalation of a propane reefer might help remove the heat ,by convection , rather than blow it into the coach.
Also will make it Easier for the next owner to do it His Way, should he be a camper.
FAST FRED |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 18, 2004 - 10:43 am: | |
Actually my intention is to research and play around with electric refers until I can find or make one effecient enough to run off the house batts maybey solar, and use it for boondocking. I have only ever stayed in an RV park just before crossing the border...Camp Lamd in San Diego - great place.
I am thinking of venting through the side as a 6"column of air is difficult to move effeciently without a big fan and I definately do not want that heat in the coach in the summer.
Chris |
Jack Conrad (Jackconrad) (204.193.117.66)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 18, 2004 - 12:05 pm: | |
We installed a 120 volt AC 16" axial fan at the bottom rear of our house type refrigerator. This fan is wired into the compressor circuit so that it comes on when the compressor is running. This fan pulls cool air from near the floor, draws it across the compressor and then pushes the air up the back of the refrigerator acorss the condenser coils. The air then re-enters the coach interior through vents near the ceiling. Using a laser temperature gun, we have never seen a temperature difference of more than 8-10 degrees between "room air" and the air in the enclosed area above the refrigerator. Hope this helps, Jack |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 18, 2004 - 7:11 pm: | |
Jack - has this helped the effeciency of the refer???
Chris |
Jack Conrad (Jackconrad) (204.193.117.66)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 18, 2004 - 8:38 pm: | |
Seems too have helped. I do not have a wattmeter to confirm this, but it seems like refrigerator runs less and battery bank last longer between recharges. Email me off board and when I get off duty tomorrow AM, I will try to find the article I wrote for Coach Builders Bulletin about this project. I can email it to you if you like. Jack |