Alloy
Well-known member
30A RV or 30A marine. Keep the option open so you can plug a the AC into a generator. With line loss 15A cords/plugs get warm.
2200 watts of solar on the roof?
- Thread starter MTVR
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30A RV or 30A marine. Keep the option open so you can plug a the AC into a generator. With line loss 15A cords/plugs get warm.
Joe917
Explorer
I agree completely. My point was not go with the best gc batteries, it was go with more or lithium.
OP needs a generator for air con. running the main engine for power makes no sense.
That's what the 2,250 watts of solar panels on the roof are for. The engine's large-case 150-amp 24V alternator (the equivalent of a 300-amp 12V alternator) would just be a backup, in case we are ever unfortunate enough to find ourselves somewhere that it's 100 degrees in the dark, lol...
Here's some info on polyiso
Cold-Weather Performance of Polyisocyanurate - GreenBuildingAdvisor
The ability of insulation products to resist the flow of heat changes with temperature. Most insulation products — including fiberglass batts, extruded polystyrene (XPS), and expanded polystyrene (EPS) — perform better at low temperatures than high temperatures. At lower temperatures, there is...www.greenbuildingadvisor.com
That article is only viewable to members.
If you have a concern about polyiso, can you elaborate?
FWIW, we are more concerned about insulation against heat, than we are about cold. We can always put more clothes on, but there are only so many clothes you can take off...
Ah, I just got that!
I wouldn't want to risk damaging $2,000 worth of lithium with a second parallel DC-DC charger, if I had some kind of a mishap in which the second charger was on when the mini-split's compressor wasn't.
But clever idea- thanks...
dreadlocks
Well-known member
If the DC charger takes a input signal to turn on/off, like many do so they can be switched w/ignition or manually.. it would just be wiring up a relay within the AC so when it kicks the compressor on you can get a signal to that DC charger and the AC will just automatically run off the engine when its available.. if its sized for the load or slightly under (which you should probably actually measure and not trust spec sheets) then you wont really risk feeding your LFP bank too much current, while having enough current for the AC.. of course this is all theory, but things like this are rather simple and it would require no extra actions on your part to run the split house AC off the engine when you wanna.
Probably other ways to do this too, could put a transfer switch on inverter's DC inputs so it switches over to the engine circuit when its on.. would need to be very heavy duty to handle the current and it would be your truck battery taking abuse from startup surges and whatnot instead of your house battery.
Probably other ways to do this too, could put a transfer switch on inverter's DC inputs so it switches over to the engine circuit when its on.. would need to be very heavy duty to handle the current and it would be your truck battery taking abuse from startup surges and whatnot instead of your house battery.
Joe917
Explorer
Yes it's called night time anywhere tropical. If you never leave the desert you may be OK. We have a 200 amp 24 volt alternator, who cares, running your main engine to make power makes no sense.
Good luck with the build.
dreadlocks
Well-known member
if you want your shipping container cooled so its not 130F inside as you cross the american south west sure, but a genset is still an economical backup over a big engine.. especially if long runtimes to recharge or keep you from getting swamp ass in your sleep are in the cards.. might be hard to sleep with that big motor running too, cant imagine u wont feel it in bed..
you dont need a big honking genset for the size aircon ur lookin at, a honda 2200k portable would do the job and be super quiet compared to your military vehicle.. I got my honda mostly for running aircon, its also backup battery charger, and in the off season its my backup generator over the winter to keep the heat on in my house.. worth it.
but with LFP at its max charge rate, you can make it work pretty well using engine as backup charger instead of genset once you have your data collected.. since LFP dont need to be 100% you'll quickly figure out how much power you need to get through the night, and can just run the engine the 30-45mins or whatever it needs to get you through the night comfortably without having to endure a full charge cycle like you would want to do w/lead when the sun's just not cooperating.
you dont need a big honking genset for the size aircon ur lookin at, a honda 2200k portable would do the job and be super quiet compared to your military vehicle.. I got my honda mostly for running aircon, its also backup battery charger, and in the off season its my backup generator over the winter to keep the heat on in my house.. worth it.
but with LFP at its max charge rate, you can make it work pretty well using engine as backup charger instead of genset once you have your data collected.. since LFP dont need to be 100% you'll quickly figure out how much power you need to get through the night, and can just run the engine the 30-45mins or whatever it needs to get you through the night comfortably without having to endure a full charge cycle like you would want to do w/lead when the sun's just not cooperating.
Alloy
Well-known member
Polyiso is better for heat. The insulating qualities of polyiso drops off at 35F because the blowing agent condenses......also depends on what type you get because each manufacture uses a different blowing (gas) chemical.
Polyiso is one of the worst insulation for absorbing water so I wouldn't recommend it using it with a wood frame structure.
Using an aluminized foil in the roof and walls will reduce the amount of UV that can pass through the roof/walls.
The polyiso we're looking at is the 3.5" R-Max Thermashield 3, which has an R-value of 23.9. It has a foil face. Twenty 4'x8' boards delivered to our home, for about $1,390...
And we're planning to completely seal the inside and the outside with epoxy before painting it, so we're hoping the moisture never even reaches the polyiso.
And we're planning to completely seal the inside and the outside with epoxy before painting it, so we're hoping the moisture never even reaches the polyiso.
Alloy
Well-known member
We've had days that are 90-100F and cloudy. We could see rain falling but it evaporated before it hit the ground. Humidty was horrible. AC was running off the generator 5-6 hours each day,
Alloy
Well-known member
I'm of the mind give it time it will leak.
For the cost + time sprayed urethane is R6.25/in and a much better air barrier vs rigid insulation but both polyiso and urethane absorbs water so there is no tell tale puddle of water. Neither foam will ever dry out so the moisture stays in place until the insualtion is removed.
Make sure the polyiso is dry (hasn't been stored outside) and taping the edges plus any punctures holes with aluminum tape greatly improve the water resistance.