Amps oh my

[Clean1]

I don't think its impossible or that it would require a PV array that is ostentatious - just need to keep the size of the PV array a small as the roof top (then its harder to notice), insulate the van well, use a small but super efficient AC unit, limit the amount of glass windows and use curtains to block off the front area which has the most glass for heat gain. A heavy, full height curtain right behind the driver/passenger seats is useful to reduce the amount of area required to be cool and also helps block people from viewing into the back area when parked.

The other question I have is if its not safe to take the wife and dog is it safe to leave them with the van alone then?

Awesome question..It is safe just not allowed. Thanks for the positive feedback

 

[DiploStrat]

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The only way one can have a working 12V air conditioning system is with a BIG, HEAVY battery bank... and an internal-combustion generator to recharge it. The photovoltaic componentry requirements alone would smother your two-axle rig, and serve as a ridiculous sign of ostentation in the third world that no tourist with any degree of prudence would willingly display.

Sorry, but I can't agree with your comments:

-- You can certainly run an air conditioner with a battery bank; at this time of year I do it all the time. The variables are how long and at what temperature.

-- I recharge my batteries very quickly with a combination of proper wiring to the starter battery/alternator and a solar array on the roof. I do not have a generator.

-- Most of Latin America is not Third World and while no tourist vehicle is going to look like a local vehicle (the license plates alone prevent that), it is unlikely that you could ever have a vehicle that is more ostentatious than many local vehicles. In any case, the solar panels on my truck, for example, are invisible from the ground.

The real secret of survival in the Third World is the secret of survival anywhere; learn how to respect and get along with people. I have met backpackers who are far less culturally aware and give much greater offense than most overlanders, whether they travel by bicycle, motorcycle, or 4x4 motorhome.

 

[Haf-E]

So - a side question - is the Transit van a diesel or gasoline version? If diesel what is the plan regarding the ULSD requirement?

A roof top type AC unit is not ideal - it reduces the amount of area for the solar array, makes the vehicle taller, adds weight up high and is exposed to more heat and sun up there. Check out some of the small "portable" type units which have hoses for the outdoor air or the small units used with some of the teardrop trailers - they are also sold to cool dog houses - but I think they need to be installed externally to the cooled space which is not ideal.

There are some DC air conditioners but they are mostly made for boats or long haul big rig sleeper cabs and seem to be very expensive.

Good luck!

 

[dwh]

Full load cooling is approximately 12amps

12 amps at 120v - which will be 120a when sucked out of the battery at 12v by an inverter.

watts = volts x amps

120v x 12a = 1440w

12v x 120a = 1440w

Now if I am gone for 4 hours and the a/c has been running the entire time 12amps x 4 hours=48amps. Correct?

No, not correct. Should be 120a x 4h = 480ah.

 

[Clean1]

So - a side question - is the Transit van a diesel or gasoline version? If diesel what is the plan regarding the ULSD requirement?

A roof top type AC unit is not ideal - it reduces the amount of area for the solar array, makes the vehicle taller, adds weight up high and is exposed to more heat and sun up there. Check out some of the small "portable" type units which have hoses for the outdoor air or the small units used with some of the teardrop trailers - they are also sold to cool dog houses - but I think they need to be installed externally to the cooled space which is not ideal.

There are some DC air conditioners but they are mostly made for boats or long haul big rig sleeper cabs and seem to be very expensive.

Good luck!

Van is a gaser, the DEF system was the reason I did not go with a diesel. Agreed the roof top is not ideal and I am going to take a closer look at a DC split system. I can probably
mount the compressor somewhere on the back of the van and cover it when not being used. I have checked into the truck bunk coolers and they are pretty expensive. They usually
require 4 batteries and BTUs are pretty low. So I KNOW it is possible to run an a/c off of batteries, I just have to find an efficient enough one to justify the price and extra space it takes up. Some of the boat/marine ones are interesting but they use water to cool instead of air. Thanks for the question.

 

[Clean1]

12 amps at 120v - which will be 120a when sucked out of the battery at 12v by an inverter.

watts = volts x amps

120v x 12a = 1440w

12v x 120a = 1440w




No, not correct. Should be 120a x 4h = 480ah.

DWH your the man and thank you. Thats what I was missing. Thanks for the clarification and help.

 

[Haf-E]

BTW - on mounting the solar - its important to leave an airspace behind them and to allow for air flow between the solar modules - about a 1 inch gap behind and on the edges seems to work well in order to allow the hot air to flow out. Properly done it will also reduce the load on the air conditioner by shading the roof.

I don't like the flexible "thin film" type solar modules as they do not allow this air space. I have used the standard glass solar modules with aluminum frames on two different rigs since 1998 without any issues. Also - using a 24 vdc solar array (60 to 72 PV cells in series type solar modules) with a step down type solar controller to get it to 12vdc would be the best choice in my experience.

 

[DiploStrat]

Sooo, we still need to understand what you are trying to do ...

While much of Central America can be hot and humid at low altitudes, most of the popular tourist areas of South America tend to be very cold and very dry. Again, are you talking about a "few hours" or 24/7? Makes a tremendous difference. If a "few hours", then you are looking at numbers like mine, especially if you can cool the cabin while driving, park in the shade, and then drive again. If you require 70F overnight in Panamá in the rainy season, then I would invest in a genset.

But, is air conditioning a REAL requirement? I lived in Panamá (as an example) for years with a dog, a wife, and no air conditioning. Granted, I lived on a ridge, but the only time it was really vile was between seasons. And then you simply took a shower before bed. Maybe what you really need is a bigger water tank. Just a thought.

 

[Clean1]

BTW - on mounting the solar - its important to leave an airspace behind them and to allow for air flow between the solar modules - about a 1 inch gap behind and on the edges seems to work well in order to allow the hot air to flow out. Properly done it will also reduce the load on the air conditioner by shading the roof.

I don't like the flexible "thin film" type solar modules as they do not allow this air space. I have used the standard glass solar modules with aluminum frames on two different rigs since 1998 without any issues. Also - using a 24 vdc solar array (60 to 72 PV cells in series type solar modules) with a step down type solar controller to get it to 12vdc would be the best choice in my experience.

Great stuff Haf-E. Thanks for the tips they are much appreciated..