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If you download the Heat loss calculator and look at the numbers, I think the heat loss from a well insulated van could be reduce by 4/5's to ~ 3,000 BTU's / HR. But probably still to much amp draw to run through the night on battery power. So no boon-docking with air conditioning without a generator. It would take a minimum of a Honda 2000?

On a really hot day it could supplement the vehicle air conditioning while driving with an alternator to battery charger running.

How long does the compressor cycle on?

http://www.buildagreenrv.com/design-and-build-information-for-camper-vans/heat-loss-calculator-for-camper-van-conversions/
Hi,
The heat loss calculator is mine -- happy to answer any questions about it.

Couple of things to bear in mind when using it for heat gain (AC) are that people, pets, cooking etc. add to the heat gain. This is a plus when heating, but a minus when cooling. Heat gain per person is about 300 BTU/hr depending on how active they are.

The other thing is direct solar gain through windows. This can be a big swinger -- for a window in direct sun with no shade on it, it can be 200+ BTU/hr per sqft of window. So, well fitted reflective window shades are a must -- even better if you can shade the outside of the windows.
Of course, parking in the shade (if you can find it) makes a big difference.

One solution that involves some DIY is to adapt a small room AC to the van. Something like this one: https://www.amazon.com/Frigidaire-FFRA0511R1-Window-Mounted-Mini-Compact-Conditioner/dp/B00W2KG92Y/ref=sr_1_2?ie=UTF8&qid=1483755475&sr=8-2&keywords=frigidaire+small+room+ac
Its a SEER 11, which is pretty good, especially compared to RV AC units.
The 5000 BTU/hr should be OK for a well insulated van with good shades on the windows -- but, it might take a while to catch up if the van starts out hot.
I've seen youtube videos from people who have adapted this kind of AC.

If your steady state heat gain is (say) 3000 BTU/hr, and you have a SEER 11 AC (COP = 3.22, efficiency = 322%), then the steady wattage would be (3000 BTU/hr)(1/3.412 BTU/hr/wat) (1/3.22) = 273 watts. This would be an average of (273 watts)/(12.5 volts) (1/0.9 inverter efic) = 24 amp. Or, 24 amp-hrs per hour of operation when producing an average of 3000BTU/hr of cooling. Maybe something that would be workable without shore power, but a BIG house battery, and operating only part of the day.

Specs here: http://www.frigidaire.com/Home-Comfort/Air-Conditioning/Window-Mounted-AC/FFRA0511R1/
The spec says 450 watts when cooling at 5000 BTU/hr, so good agreement with calc above.

Gary
 

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i am boondocking with air conditioning at least a couple nights a week with a van insulated to R-9, a 440 AH battery bank driving an inverter, charged with 650 watts of solar and a 60 amp battery to battery charger, plus a backup 100 amp charger built into the inverter that runs on shorepower 1 or 2 nights a week in a campground to make sure the batteries are staying fully charged all week because driving and sun light may not always be enough.

over the road truckers are doing this every night because the law says they cant run there engines at night, so i have loosely based my electrical system on there system, but about the only real difference with my system is i have solar and drive less some days.
some info on truck Auxiliary Power Units: http://www.trojanbattery.com/pdf/TRN_OverDriveWhitePaper0910FL.pdf
 

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Couple of things to bear in mind when using it for heat gain (AC) are that people, pets, cooking etc. add to the heat gain. This is a plus when heating, but a minus when cooling. Heat gain per person is about 300 BTU/hr depending on how active they are.

The heat gain from pets is significant- I built an 8x12 portable wood cabin that was very well insulated with a small propane radiant/open flame heater..
I was surprised that with two 55 lb dogs and two people in it I found we needed essentially no heat until below 40F!
Dogs, of course have a higher body temp than humans.
 

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over the road truckers are doing this every night because the law says they cant run there engines at night,
In some places that is true- in others it is not.
Love's built a truckstop at an exit 2 miles from my home- outdoors on a quiet night there is a perceptible rumble from 100+ trucks idling.
I'm sure glad I don't live closer...many homes are almost right up on it- they were there first and I'd bet the owners are pissed!
 

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In some places that is true- in others it is not.
Love's built a truckstop at an exit 2 miles from my home- outdoors on a quiet night there is a perceptible rumble from 100+ trucks idling.
I'm sure glad I don't live closer...many homes are almost right up on it- they were there first and I'd bet the owners are pissed!
the trucks may have only stopped for coffee, fuel or food, the law says they can not leave then idling more then an hour or two, when the truckers are asleep they have to shut them off! there may be exceptions to that law in extreme cold since diesels are hard to start when very cold and the fuel solidifies into wax.

sounds like you have the same zoning laws we have here: houses and mobile homes in close proximity.
 

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What air conditioner are you using?
a 2 hose Whynter model ARC-141BG portable air conditioner 14,000 BTU. using a maximum of 10.8 amps at 120 volts AC, intake and exhaust floor vented on opposite sides of the van. powered by a Magnum Dimensions MS2012 inverter with an output of 16.7 amps at 120 volts AC.
 

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the trucks may have only stopped for coffee, fuel or food, the law says they can not leave then idling more then an hour or two, when the truckers are asleep they have to shut them off! there may be exceptions to that law in extreme cold since diesels are hard to start when very cold and the fuel solidifies into wax.
Define "the law". As far as I can tell here is no blanket (federal) law against idling.
In SC where I am under state law trucks are allowed to idle while the driver is sleeping or resting...or when outside temp is above 80 or below 40.
 

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Define "the law". As far as I can tell here is no blanket (federal) law against idling.
In SC where I am under state law trucks are allowed to idle while the driver is sleeping or resting...or when outside temp is above 80 or below 40.
i have no clue? i told the local Trojan battery distributor that i wanted deep cycle AGMs for inverter use, i had wanted some 8Ds i picked out before hand but he said he had none in stock. he then said he had Trojan 'overdrive' group 31s in stock that all of the truckers used in there truck APUs, i got them at wholesale (i bought 6 of them) which is nearly half of what they sell for on amazon!

http://www.trojanbattery.com/markets/transportation/
 

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Many OTR trucks use a APU consisting of a small diesel engine driving a generator. You will most likely see these mounted to the outside of the frame behind the fuel tank.

A basic unit will start at around $3,000 and go up depending on additional items such as battery packs, truck coolant heater, engine driven AC and expresso maker. Well maybe not that last one. But if you look inside a modern truck sleeper unit they can put a class A motorhome to shame.

So yes, many OTR trucks use battery packs just like we do but they don't really rely on them to power the AC unit. They use them just like we do. TV, microwave, lighting and other accessory items when they don't need cooling or heat.

I'm sure some trucks are starting to use lithium battery packs with enough capacity to run everything but they are still a very small percentage.

As far as laws are concerned they vary from state to state and even by locality. PA is very strict and OH has none. Yet certain cities in OH might have local laws against idling.

If you live near a truck stop without any regulations get the law changed. Of course even the APU units make a fair amount of noise. Compare it to a campground full of RVs all running their generators.

???
 

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Gary,

Nice job on the Heat Loss Calculator and your website. Lots of great information.

How many amp hours per hour of operation would you estimate the Mach 8 to draw while running on low? Do they give enough information to estimate that number? http://www.airxcel.com/coleman-mach/products/air-conditioners/ultra-low-profile/mach-8/mach-8-cub
Hi,
The link does not give the power to run on low, but the YouTube video in one of the posts above (I think) says its 1080 watts running on low. So, it would be drawing (1080 watts)/(12.5 volts)(0.9 inverter efic) = 96 amps (ouch!), and would use 96 amp-hrs per hour of use. But, this is running continuously on low cool -- it would likely only be running part of the time depending on the outside temp and insulation,

Gary
 

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a 2 hose Whynter model ARC-141BG portable air conditioner 14,000 BTU. using a maximum of 10.8 amps at 120 volts AC, intake and exhaust floor vented on opposite sides of the van. powered by a Magnum Dimensions MS2012 inverter with an output of 16.7 amps at 120 volts AC.
I have been thinking about this type AC. Are you pleased with unit and how is noise in the van?
 

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a 2 hose Whynter model ARC-141BG portable air conditioner 14,000 BTU. using a maximum of 10.8 amps at 120 volts AC, intake and exhaust floor vented on opposite sides of the van. powered by a Magnum Dimensions MS2012 inverter with an output of 16.7 amps at 120 volts AC.
And do you have any pics of the setup you'd care to share?
 

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I went down to the Yellowtail Dam Afterbay in in Montana today. -19 F when we got there. Forget the air conditioner. I need a 4x4 van with a good heater.
That looks like one of those drift boats I've seen out there. Saw quite a few while pedaling along the Madison River.
 

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I have been thinking about this type AC. Are you pleased with unit and how is noise in the van?
it works quite well but my van is overinsulated compared to many vans here, R-9 foil backed polyiso in all 4 walls, floor and roof of the living area. the portable ac is in a compartment in the back of the van outside of the living area so it is pretty quiet just blowing ac air thru a short duct into the living area. but it is also a dehumidifier and has a tank that should be dumped every day or two when driving because it will make a mess sloshing back and forth, it is easy to drain out the back door thru a screw on hose. i have not found out yet if it will work with a continuous drain maybe thru a hole in the floor? (it may use some of that water for internal cooling because the exhaust hose blows hot moist air!) it is built to be banged around a little bit because it is designed to be moved from room to room in a house, but i worry large potholes and dips in the road may be too much for it? the truth is it is just an experiment since the original reason i bought it was so in the short term i could cool and start my build in a hot and humid mississippi summer! i may end up with a roof mount yet, but i do not think so because i like the at least part time stealth van approach!
 

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And do you have any pics of the setup you'd care to share?
no, sorry, i am kind of living in the past with some things, i got my first cellphone 3 years ago, a flip phone i am still using. (i have promised myself i will buy one of those newfangled cameras and learn how to put pictures on a computer before my build is done!)
 

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For general reference and without addressing specific comments above, I have used a free standing residential floor unit in an RV application.

It was a fifth wheel toy hauler without AC in the garage/guest room. The space was 12' long, 8' wide and 10' or 11' high. Roof insulation was standard RV, walls were standard foam sandwich, back wall was the ramp door which consisted of several layers of plywood with a gelcoat outer skin and the floor was a single layer of 3/4" plywood on a steel frame (no further insulation). The front wall was luan on frame separating it from the main part of the fiver. There were three large single pane windows and a man door.

This space got hot, quicker than the rest of the RV. It was insulated more poorly.

The AC was an 8000BTU unit. I ran it on a 15A circuit and never popped a breaker. The 4" vent hose went through a hole in the floor to the outside. When not in use I had a screw in plate in the hole. Condensate was mixed in with exhaust and disappeared. It kept the space at 72º no problem. It rattled around back there for 7000 miles sitting on the vinyl floor and did not seem to suffer any negative effects.

I plan on doing the same thing as described above. Put the (same) unit (I sold the fiver) in the van tastefully camouflaged in a cabinet with metal screening.
 

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