Some more thoughts on heater mode for the Wave 2:

• I'm having a lot of buyer's remorse on the purchase because I didn't realize the 41F rating was for exterior temperatures, not interior. I thought as long as the unit inside your conditioned space was >41F you'd be able to run things, it turns out that isn't the case.
• In hindsight, I should have realized 41F was the exterior temp rating... the unit moves heat from the exterior air by pulling outside air in, pulling heat from it (making it colder), and then blowing it back out. I believe Ecoflow artificially limited the compressor to keep the condenser coil at ~34F in order to prevent ice buildup.
• Below 41F exterior temps, you should be able to use interior air as the source for your exhaust loop. As we learned in the background section though, that's going to cut your efficiency by quite a significant margin, probably in the 50-60% reduction range. That will still make things better than a space heater, but you'll maybe only get a COP of ~1.25 instead of 1.0 with a space heater? Much much worse than the ~2 COP I was hoping for.
• If you can fit a residential condenser somewhere on your build, a residential mini split will easily give you significantly more performance down to extremely low temperatures (current state of the industry is down to -22F!) Those units at more reasonable temperatures have COPs in the 3+ range. If you're trying to go to electric only heat like I was, I think this is the only reasonable method to accomplish it.
• With warranty ending modifications, I think there might be a way to move some thermocouples around and trick the ecoflow into taking its condenser side below 34F in heater mode. You would have to add some external logic to cycle a resistive heater to turn on and melt any ice, or reverse the unit on a timer and run in "A/C" mode to warm up the condenser and melt off any ice. I don't plan to do anything like that until next winter after my warranty is up.

 

Not moving the condensate from the evaporator to the condenser is a big design problem. Even if they had to put a cheap little diaphragm pump in it it’s needed to be effective in humid environments. The latent heat is just as important as temperature and it shows a lack of understanding by the designers. That and a bit of insulation on the supplied hoses would make a big difference.

Two hose ACs are a hard thing to make work correctly. The heat pump we use is basically a portable AC unit in a styrofoam box and it sits in holes cut in the floor of the van instead of having hoses. It works okay thanks to its insulated box but that’s a tough thing to pull off in a portable unit.

 

Not moving the condensate from the evaporator to the condenser is a big design problem. Even if they had to put a cheap little diaphragm pump in it it’s needed to be effective in humid environments. The latent heat is just as important as temperature and it shows a lack of understanding by the designers. That and a bit of insulation on the supplied hoses would make a big difference.

Two hose ACs are a hard thing to make work correctly. The heat pump we use is basically a portable AC unit in a styrofoam box and it sits in holes cut in the floor of the van instead of having hoses. It works okay thanks to its insulated box but that’s a tough thing to pull off in a portable unit.

Their actually is a diaphragm pump! It pumps condensate from the base to the top of the condenser heat exchanger. The only issue is that the base of the unit serves as the reservoir, and airflow on the conditioned side passes over that reservoir picking up moisture. Longer test periods would continue to reduce RH.

 

Ah, one more major gripe with the wave 2... The only way out of the box to power it via DC is if you buy the addon battery or another ecoflow power station. Ecoflow uses a proprietary xt150 with data comm that only activates the compressor if it is attached to one of their batteries. A DIY xt150 or giving it sufficient power through the Xt60 isn't enough to trick the unit.

I purchased the battery addon and plan to give it a constant 48v through the Xt60 to keep it powered via DC, but it's not consumer friendly to lock you into it this way. I'm sure it's great for their margins though.....

I saw someone had success on a wave 1 opening it up and shorting out some of the internal boards to trick the unit, but that's definitely warranty voiding.

 

Yes, to me one of the biggest minuses for the AIO is the proprietary interfaces. Hopefully right to repair legislation may help with this in the future but for now it is what it is and manufacturers find ever more devious ways of locking the customers in...
I have not looked into these much; I assume some manufacturers are better than others in this regard.

 

I came to these detailed test results via another comment you made, @asot550, on another thread. Thanks for all the nerdiness (that's a compliment by the way)!

That little Toshiba is not only cheap ($170) but isn't super power-hungry (at 460W).

If you don't mind a minor thread-hijack, I've always fantasized about taking apart such a unit and turning it into a hack mini-split. e.g. separate the condenser coils, compressor, and cooling fan (i.e., the "condenser stuff") from the cooling coils and relocate the "condenser stuff" outside of the van somewhere. Only the cooling coils and a smaller quieter user-supplied fan are inside the van.

Importantly for me, this will move the noisy stuff outside.

Recently, there have been vehicle-oriented smaller 12V mini-split AC units that aren't exorbitant in cost and they don't draw huge amounts of power. But "not exorbitant" is still a fair amount of money and I'm cheap. Also, they seem to be akin to Chinese diesel heaters (poor documentation and perhaps questionable parts) so I'm somewhat dubious about long-term reliability. Contrast this with window units like the Toshiba: cheap and manufacturers seem to have perfected the reliability.

I think I'm handy enough to take apart a window AC unit. I suspect I would have to slip an HVAC technician a couple hundred bucks under the table to extend the tubing (welding and dealing with the refrigerant issues).

Do you or anyone else think this would work?

 

Sure, anything is possible with enough time, money, and skills 😳

You wouldn't be able to turn it into a heat pump since you need a reversing valve, but I don't see why you couldn't split it open and relocate components.

Challenges you'll have to overcome include: extension of the refrigerant lines, brazing new copper tubes, figuring out if the compresser has any issues with a longer lineset (idk the answer to this), determining the appropriate amount of additional refrigerant to charge things with, a way to collect and dispose of condensed water from the interior, a way to pump water to your external radiator (the fans in window units have very low clearance to the base pan and actually pick up water from the base to spray over the condenser coils), and possibly other unknown unknowns?

Tbh, if going through all that trouble I think the only mod I can see being useful is figuring out a way to undermount the condenser and route your lineset through the floor. You'd still have the water issue, but lineset length is unlikely to be an issue. You could collect water inside and then use a little diaphragm pump to spray the collected water onto the rear of the condenser.

I think the time is better spent figuring a way to mount a window unit rather than re-engineering a split system.

 

Thanks for that. Originally I was thinking of undermounting the condenser stuff but having traversed a long dirt highway, I saw how much crud can accumulate underneath (it looks enough to kill an undermount AC system; I don't know how commercial units survive). My current fantasy is mounting it on one of the rear doors and having the cooling coils on the other side and thus lineset length wouldn't increase much.

Condensed water would just be collected and let drip out through a tube and out through the door but maybe I'll store it into a small tank (see below).

I wasn't aware of the role that condensed water from the cooling coils played in cooling the condenser coils. Makes sense. Maybe a tank to collect the cooling coil water supplemented by water from my freshwater tanks? Maybe some kind of pump (diaphram?) or simple gravity feed to put water into the airstream of the cooling fan? --It's all part of the fantasy!

PS: I'm lucky enough to have the time. I have the basic campervan building skills but will have to get an HVAC tech to step in for some of it.

PPS: or just bite the bullet and roll the dice on one of the new-fangled backpack AC units.

 

@travelvanvan check out this YouTube video detailing his trials and tribulations with his mini fridge. This guy has plenty of great content in the "hacking" space. If don't think I ever would've considered attempting an a/c mod if I hadn't seen this video... It's similar technology and seemed like a magic black box to me at one point. Now I know it's not as complex as I once originally thought:

 

What a cool guy! I prefer these vanlife videos to the, um, (melo)dramatic ones.

I'm not sure why he didn't learn from his previous drilling mistake. That interior fridge van could have been easily JB welded on (since he seems to have an ample supply of that substance).

Also, a bit better ventilation could have allowed his 1st fridge to last indefinitely (talk about cheap and reliable appliances that have been "perfected").

But, as you say, this is the same type of effort and skills needed to hack a mini-split from a window AC.

 

If you just cut a hole in the rear door you'd be able to mount a window unit without doing any of these mods. All you'd need is a platform and sufficient bracing/weather sealing. I'm pretty sure this is how most people do it in a van build.

 

I've seen an exterior door hatch with a drawer slide to extend it from the back door or the side wall when needed, but pull it in while driving.

 

If you just cut a hole in the rear door you'd be able to mount a window unit without doing any of these mods. All you'd need is a platform and sufficient bracing/weather sealing. I'm pretty sure this is how most people do it in a van build.

For me, that'd look a little too ghetto and/or obvious. I will admit that my interior build is ghetto but outside, my van looks pretty normal (intentionally so as to avoid attention).

I've seen an exterior door hatch with a drawer slide to extend it from the back door or the side wall when needed, but pull it in while driving.

I have seen that (and also fantasized about that) but I think the skills to make it work well are similarly hard, perhaps harder than hacking the window AC.

 

I have seen that (and also fantasized about that) but I think the skills to make it work well are similarly hard, perhaps harder than hacking the window AC.

Doesn't seem too bad to me, just make a bottomless drawer for the a/c to sit on, attach sliders to the drawer, cut hole in van, slide out and done. You could make the hatch hingeable or a removable panel. Heck, buy a box that's intended for external tool storage and cut off the box and just use the flanged front. No one would be the wiser that it wasn't a tool box and it'd have a lock to prevent anyone from messing with it

 

@MaggieMarty
this?
https://www.fordtransitusaforum.com/threads/window-a-c-converted-to-mini-split-success.86312/

 

Yes!! Of course you beat me to it!

 

Reviving an almost year old thread.
All good reads and so much info!
I have my Ecoflow Wave 2 in the back of a cabinet with two small drawers in front of it. The exhaust is going through the floor to the outside, the intake air is coming from the front of the van but still in the living space. I have the cooled or heated air coming from under the cabinet around the middle of the van. It seems to work great for me the way I have it setup. I didn't want a big unit on the roof.