zero Posted August 6, 2015 Share Posted August 6, 2015 I just bought eight 100 watt solar panels for around $1000. Ten years ago they would of cost $3300. I also bought four solar controllers for $18 each, instead of one big controller for big bucks. Solar is amazingly cheap right now if a person shops around. I wish I could say the same for batteries. They just keep going up and up. Ten years ago I could buy a Trojan T-105 or Deka equivalent for $48. Now they are sometimes three-times that price. The newest tech for solar batteries is lap-top type computer batteries all wired together (lithium). Half the weight of lead-acid batteries and twice the price. No great break-through yet as I see it. Mr.Musk of Tesla motors just jumped into the business with them. But - if he starts selling them in smaller units - MIGHT be a neat power package for an RV. By the way, I know several people in Florida who never use AC. On the west-cost around Punta Gorda. I went there a while back. One friend has a house with real trees giving natural shade and windows that opened and no AC and all was fine. Not far away - my ex-sister-in-law has a place where the windows don't even open anymore and seems the AC runs ALL the time. I couldn't stand the place. Hey, to each his own. Quote Link to comment Share on other sites More sharing options...
Totem Posted August 6, 2015 Share Posted August 6, 2015 all things can be had en masse on ali-baba ... while at the same time supporting China. Solar can be had there for 48 cents a watt. That's 120 bucks per 250 watt panel IF you buy 10... Quote Link to comment Share on other sites More sharing options...
jjrbus Posted August 6, 2015 Share Posted August 6, 2015 If I did decide to go with some solar, which is very unlikely. I would try to join it to the house. Jim Quote Link to comment Share on other sites More sharing options...
jjrbus Posted August 6, 2015 Share Posted August 6, 2015 By the way, I know several people in Florida who never use AC. On the west-cost around Punta Gorda. I went there a while back. One friend has a house with real trees giving natural shade and windows that opened and no AC and all was fine. Not far away - my ex-sister-in-law has a place where the windows don't even open anymore and seems the AC runs ALL the time. I couldn't stand the place. Hey, to each his own. Depends on the time of year, I never turn the AC off in summer. Right now it is 90 with 60% humidity. It would be unbearable without AC, for me anyway! Plus houses get moldy here. In the winter we get some great weather with no AC needed. Jim Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 6, 2015 Share Posted August 6, 2015 The way I figure it The toy home roof completely covered with solar panels over AC units vents etc would only be able to supply maybe a 1,000 watts at high noon. That in it self would not be able to power an AC much less charge the batteries at the same time.So at the hottest part of the day even the greatest solar gain it would not cut it. I have no AC but I do have a Fantastic fan a 100 watt panel will power it on low speed and still give the batteries a bit of a charge on high the fan wins the batteries loose. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 7, 2015 Share Posted August 7, 2015 they quote out a full setup for 4k. They are gouging on the solar panels, the panel's brackets, the PWM controller by 25% Methinks you could source the other parts out the door for a grand total including AC unit of $3000. You would also at that time have a fantastic 48v power setup, heater etc. I am sooooo wanting to do it. the main thing I am having problems with is getting the dimensions of the indoor and outdoor units. anyone find them? There is nothing in their specs that state run current that's a key issue. There is no doubt that inverter mini splits are efficient but the bottom line there is no free lunch. They have been in use in MH in Asia for some time but on a plug in basis. Quote Link to comment Share on other sites More sharing options...
zero Posted August 7, 2015 Share Posted August 7, 2015 I don't see how this so-called "new tech" is much more efficient then the standard AC units made for camper rooftops. This DC unit runs at a 885 watts input draw. I.e the same as 74 amps if at 12 volts DC, or 7.3 amps if at 120 volts AC. Yes, I know it's sold for running on 30-50 volts DC - but watts is watts. I don't see a significant gain over the standard unit. The "48" volt DC unit - to run 40% of the time for a 24 hour day - needs eleven 250 watt solar panels and twenty 6-volt batteries. The figures they give in the advertising are for only running 3.6 hours per 24 hour day. Also note that the eleven 250 watt solar panels is only in "optimal" conditions. It would likely need 20 such panels in parts of the USA with less-then-perfect sun and mounted on an RV roof with less-then-perfect angles to the sun. I suspect you could do just as well by using the best Coleman AC unit and insall solar. But you'd need so much your RV would no longer be a "recreational vehicle." More like a parked cabin on wheels attached to a lot of stuff. The big gains I've seen in solar power cooling (like freezers and refrigerators) are highly reliant on super-insulation along with efficient DC motors. Not the case with a Toyota RV unless you want to put 12" of spray foam all around the outside. Quote Link to comment Share on other sites More sharing options...
WME Posted August 7, 2015 Share Posted August 7, 2015 JDE agree, but look at all the wild ideas folks come up and think of bandwidth and time we've wasted trying to reinvent the wheel . Bottom line has always been, want AC? then get a generator or plug in to 110vac. Even Newell has come to this conclusion and they sell $1,000,000 MHs. Quote Link to comment Share on other sites More sharing options...
zero Posted August 7, 2015 Share Posted August 7, 2015 JDE agree, but look at all the wild ideas folks come up and think of bandwidth and time we've wasted trying to reinvent the wheel . Bottom line has always been, want AC? then get a generator or plug in to 110vac. Even Newell has come to this conclusion and they sell $1,000,000 MHs. Road-Trek has one slight variation with their E-trek Eco RV. Just one diesel engine that runs the RV down the road and also powers a big alternator under the hood that is capable of running the AC. Also has 240 watts of solar on the roof to "help out." Has a 3 liter diesel engine, 760 amp-hours in batteries, and a 220 amp/3000 watt alternator under the hood that can run the AC with the engine idling. Also has AWD and a hi-low range. ONLY $140,000! It's an interesting concept. If I was only using AC once in awhile - I'd rather have just one engine to deal with then two. Quote Link to comment Share on other sites More sharing options...
Totem Posted August 7, 2015 Share Posted August 7, 2015 the two times you need AC most in an RV are high noon when driving and possibly to cool it down in the evening before bed; again to cool the heat coming from the floor (from the transmission). If you are on shore it doesn't matter run it; but the context JDE is when NOT on shore. 3.6 hours is looking pretty sexy to me then; given I don't drive more than 6 in a day and during that 6 I will break to eat somewhere for half hour at least. The specs for that are 5 250 watt panels that easily will fit on the roof. No this is not the solution to full time cooling, but it could be a great solution. The more sunny and hotter a day is the more I demand AC and the more power those panels would be kicking. But there is another product that people haven't discussed in here yet... and it would not require much fuel 1 gallon to run 10 hours on a 2000 watt generator. http://securepets.com/PortableAirConditionerForTRUCKS.html boom. Quote Link to comment Share on other sites More sharing options...
linda s Posted August 7, 2015 Share Posted August 7, 2015 My home portable air conditioner with 8000 BTU's uses less amps and is quieter than this 2500 BTU model. Way cheaper too. I do use it in my camper when going to hot areas. Fits in my tiny Sunrader behind the passenger seat and I can still get in the door Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted August 7, 2015 Share Posted August 7, 2015 . But there is another product that people haven't discussed in here yet... and it would not require much fuel 1 gallon to run 10 hours on a 2000 watt generator. http://securepets.com/PortableAirConditionerForTRUCKS.html boom. I suspect that is more marketing hype. Those AC units come in two sizes -the 2500 BTU that draws 480 watts and the 5000 BTU that draws 700 watts. Making that sort of power with a modern gas-driven generator is going to result in around 3/4 quart per hour. 10 hours would use 1.8 gallons with the AC running constantly. So 1 gallon would be with the AC on half the time. I don't use AC except for rare occasions when our rig is parked (no air movement), it's real hot, and our dog is inside. So I don't really know how many BTUs a person needs or wants to feel good in an RV. But - I doubt 2500 BTUs is going to amount to much in a 21 foot RV on a real hot day. At least not when only running half the time. The 5000 BTU unit draws 9.5 amps on 120 VAC - so I don't see where it's any more efficient then many of the usual RV units. Maybe I'm missing something here? Quote Link to comment Share on other sites More sharing options...
Totem Posted August 7, 2015 Share Posted August 7, 2015 My home portable air conditioner with 8000 BTU's uses less amps and is quieter than this 2500 BTU model. Way cheaper too. I do use it in my camper when going to hot areas. Fits in my tiny Sunrader behind the passenger seat and I can still get in the door Linda S where do you run the dryer exhaust tube? I tried one of those prior to getting my mach 3 and replaced it. Also the model I was referring to was the 5000 BTU. How many square feet is a sunrader for living space anyway? Says it does 1200 cubic feet. seems about right. Quote Link to comment Share on other sites More sharing options...
Totem Posted August 7, 2015 Share Posted August 7, 2015 I suspect that is more marketing hype. Those AC units come in two sizes -the 2500 BTU that draws 480 watts and the 5000 BTU that draws 700 watts. Making that sort of power with a modern gas-driven generator is going to result in around 3/4 quart per hour. 10 hours would use 1.8 gallons with the AC running constantly. So 1 gallon would be with the AC on half the time. I don't use AC except for rare occasions when our rig is parked (no air movement), it's real hot, and our dog is inside. So I don't really know how many BTUs a person needs or wants to feel good in an RV. But - I doubt 2500 BTUs is going to amount to much in a 21 foot RV on a real hot day. At least not when only running half the time. The 5000 BTU unit draws 9.5 amps on 120 VAC - so I don't see where it's any more efficient then many of the usual RV units. Maybe I'm missing something here? 1.) it would easily run off a 2000 watt genny 2.) you get to run the ducts yourself not half @$$ it through a window or remove a cabinet to install it 3.) with an energy efficient inverter generator that throttles in eco mode it would in fact only consume 1 gallon in 10 hours. try doing that with your 13,500 roofy. yep you missed it. 4.) it heats in winter Quote Link to comment Share on other sites More sharing options...
linda s Posted August 7, 2015 Share Posted August 7, 2015 where do you run the dryer exhaust tube? I tried one of those prior to getting my mach 3 and replaced it. Also the model I was referring to was the 5000 BTU. How many square feet is a sunrader for living space anyway? Exhaust tube goes out the passenger window with some foam board blocking the opening. Privacy curtain separates the front area so I don't cool that. At 110 in Fresno 8000BTU's only got my camper down to 80 but 80 was heaven Linda Quote Link to comment Share on other sites More sharing options...
zero Posted August 7, 2015 Share Posted August 7, 2015 1.) it would easily run off a 2000 watt genny 2.) you get to run the ducts yourself not half @$$ it through a window or remove a cabinet to install it 3.) with an energy efficient inverter generator that throttles in eco mode it would in fact only consume 1 gallon in 10 hours. try doing that with your 13,500 roofy. yep you missed it. 4.) it heats in winter You sound like you are writiing a marketing ad. What modern generator is NOT somewhat "energy efficient?" Regardless if a Honda, Yamaha, or Generac - they will all use about 1 quart of gas per hour under a half to three-quarters load. No way can any of them supply 700 watts of electricity for 10 hours straight on one gallon. Figures about how much square footage can be cooled are also kind of meaningless. All depends on the level of insulation, how hot the ambient air temps are, etc. Eco-mode for a small inverter camping generator is great because it's as quiet as possible and RPM-matches to the load. An AC generator cannot do that since it must run at only one fixed RPM to make the 60 Hertz Cycle. That being said, a non-inverter generator run at a fixed load near the peak torque-curve of the engine - is just as efficient as any little inverter generator. Just not practical for things like camping since few of us have just one "fixed" load to match. An inverter 2000 watt generator will use approx. one quart of gas per hour making around 1000 watts. A 10,000 watt diesel generator making 2500 watts also uses 1 quart of fuel per hour. So - in that case - it's 2 1/2 times more efficient then the inverter Honda. Also a reason why Roadtrek built the Etrek Eco with an AC unit powered by the main diesel engine up front. Quote Link to comment Share on other sites More sharing options...
sherrie Posted September 11, 2015 Share Posted September 11, 2015 Just purchased the 3100W Inverter. http://www.championpowerequipment.com/products/inverters/75537i-3100w-inverter/. Love it! So far it is very good, much quieter than the 2800 Onan Camp Power that was installed. I would say the Onan was like being next to a old gas lawn mower - very loud! the Champion is like a Blender. It is a noise but when you move away from it and close a door -it becomes hard to hear. Quote Link to comment Share on other sites More sharing options...
Nam Posted June 5, 2017 Share Posted June 5, 2017 I am circling back to running my 8000btu window Frigidaire unit on the 2000W Sunforce pure sine wave inverter again. At this time if I can successfully upgrade the alternator to around 130A to 180A, I think I can run it without the generator running in the back bumper...will keep you posted in the progress. The window unit draws 7A at 120V or 840W. If the inverter has 80% efficiency that makes it 840x1.2=1000W. At 14V or 1000W/14V=72A. Stock alternator pumps out 85A I believe so double this capacity will do it...at least in theory. The battery can fill in the gap when the truck is not generating enough DC current i.e. at idle...did I miss something? This is used while running the truck only otherwise 100Ah battery can keep the AC on for about 10min or so only. I am considering adding a 2nd coach battery if needed. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 5, 2017 Share Posted June 5, 2017 I built a bus conversion and ran the roof AC off the inverter so it is doable. More gas will be used to power the alternator, so fuel savings will not be great. I don't know what size the present 12V wiring is but would assume it is inadequate and will need to be upgraded. Would guess the second battery would be needed for buffering. This is a good idea, it gets into too much effort and money to use only when driving for me. Only my opinion.   Good luck Jim Quote Link to comment Share on other sites More sharing options...
Nam Posted June 5, 2017 Share Posted June 5, 2017 Yeah I hear you Jim. The only reason for me to pursue this is my young kids (2 and 5) otherwise my wife and I are perfectly comfortable with CAB AC. I had done everything else but Alternator upgrade and is associated wiring...will see but glad you did yours. Could you please share your setup for my reference? Quote Link to comment Share on other sites More sharing options...
WME Posted June 5, 2017 Share Posted June 5, 2017 (edited) 1. BIG DC wires 0/0 or so, think welding cables and triple check the connectors. A slightly bad connector at 70 amps is a potential fire point. 2.Two batteries good idea. 3. Your truck needs 35 amps to run everything so you have 50 amps of surplus power. Up graded alternator is mandatory. Problem is driving a big alternator you may (will) need 2 belts to drive it. 4. 2 100ah batteries, discharged to 50%, would run the A/C for over 1 hr. Personally IMHO your reinventing the wheel, but good luck and keep us posted on your progress. Edited June 5, 2017 by WME Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 5, 2017 Share Posted June 5, 2017 2 hours ago, Nam said: Yeah I hear you Jim. The only reason for me to pursue this is my young kids (2 and 5) otherwise my wife and I are perfectly comfortable with CAB AC. I had done everything else but Alternator upgrade and is associated wiring...will see but glad you did yours. Could you please share your setup for my reference? My setup would not help you, it started with a 250 amp 24 volt oil cooled alternator. You are going to have to check the tables for wire size, Also for high amps you will need a quality crimper or pay someone to crimp the terminals on. Unless you are going to be driving alot, much cheaper to run the genset! Would be an interesting project and you would learn alot.  http://www.marinco.com/en/resources/wire-data/three-percent-voltage-drop Quote Link to comment Share on other sites More sharing options...
Nam Posted June 6, 2017 Share Posted June 6, 2017 Thanks Jim & WME. I am currently looking for a high output alternator....either the GM one or custom made. Found 120A ebay one that can bolted on but I don't trust that spec. So far what I found... http://www.excessiveamperage.com/ http://premierpowerwelder.com/shop/high-output-alternators/chevrolet-alternators/chevrolet-1984-1988-5-7l-high-output-alternator/ The 6 groove pulley should work with stock 4 grove belt even though I am not sure if it has enough 'grip' I can deal with cables. I actually want to measure how many amp does the AC draw thru the inverter before I order the right alternator. I also plan on installing 2 amp meters (one before the battery and one after) to monitor load One other motivation for me to pursue this project is the stock alternator seems to hang on its last leg as the battery warning light slightly light up with head lights are on at idle...which indicating low voltage... Quote Link to comment Share on other sites More sharing options...
linda s Posted June 6, 2017 Share Posted June 6, 2017 High quality Nippondenso high output alternators https://www.northwestoffroad.com/parts/alternators.php Linda S Quote Link to comment Share on other sites More sharing options...
Totem Posted June 8, 2017 Share Posted June 8, 2017 (edited) interestingly waiting on your results NAM. my high efficiency 10k btu is very similar in draw to your 8000...about 700-900 watts ish when i tested it, was drawn. If your setup works I will copy it and instead run my roof unit from the motor and ditch my HF genny unless i am boon docking in the woods. Edited June 8, 2017 by Totem Quote Link to comment Share on other sites More sharing options...
Nam Posted June 18, 2017 Share Posted June 18, 2017 Thanks Linda. Nathan at exessive amperage quoted me $365 shipped for a 170A bolt on alternator. I ordered it. Totem: I plan on using #2/0 wire from the alternator to cab battery and from cab battery to coach battery. Then I may run bundle 2C/#4AWG from coach battery to the 2000W sunforce pure wave inverter that I already have it setup. If I can free up the hitch, I can carry bike and more toys for the kids. Right now those go in the shower area.  Quote Link to comment Share on other sites More sharing options...
Nam Posted July 7, 2017 Share Posted July 7, 2017 I found out the latest is that the Honda generator cannot keep up with the AC and charge the coach battery at the same time. So to keep the coach cool for the kid, I had to turn of the DC converter/battery charger. Thanks to my complicated scheme, I can just turn on the interver which cuts off power to the converter/charger so the Honda can keep AC going. I have not yet received the new alternator yet! Quote Link to comment Share on other sites More sharing options...
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