Reasonable Window A/C? ($129, 11.1 EER, 5k BTU, 336/400 Watts)

[jonsun]

yeah total junk. but I have the hot side facing the windshield, cabin of van sealed with thick curtains and exhaust fan out of the driver side window. still nothing. Blows super cold, doesn't cool a room.

 

[itsmeagain]

I got it between the seats and semi-sealed toward the drivers compartment with the heat hose out the passenger window....doesnt make a damn dent at 95f+

I used to have one for a small room in my apartment, they're awful.

 

[highdesertranger]

speaking of the cool suits I have a couple of those bandannas that you soak in water and they stay wet for hours. put one around your neck, they work pretty damn good for keeping you cool. of course in high humidity they really wouldn't do much. highdesertranger

 

[itsmeagain]

speaking of the cool suits I have a couple of those bandannas that you soak in water and they stay wet for hours.  put one around your neck,  they work pretty damn good for keeping you cool.  of course in high humidity they really wouldn't do much.  highdesertranger

Since that post I've been watching countless DIY cool suit videos.

This is seriously becoming a consideration. If I find myself hooked to a coolant filled umbilical cord like I'm about to spacewalk myself outside of the lunar module, I promise to post a pic.

 

[jonsun]

did you go to the 24hrsoflemons forum? lmao

 

[tx2sturgis]

You laugh!

They actually make these for bikers:

http://www.veskimo.com/

http://www.roadrunner.travel/2014/04/16/cooling-vests-air-conditioning-motorcycle/

http://hogcooler.com/

 

[itsmeagain]

did you go to the 24hrsoflemons forum? lmao

I'll certainly be going there now! 

 

[itsmeagain]

You laugh!

They actually make these for bikers:

http://www.veskimo.com/

http://www.roadrunner.travel/2014/04/16/cooling-vests-air-conditioning-motorcycle/

http://hogcooler.com/

Between the crazy temps bikers and race car drivers experience..  to the lethal temperatures NASA battles against..  this really can't be the craziest idea.
Why spend money to cool the entire "room" when I'm the only one in it?   Of course there would still be a need for ventilation, but not climate control.

Edit: Also popular with firefighters, steel mill workers, and surgeons, believe it or not.

don't want this thread to stray too far from A/C...    but..      hmmmm..

 

[tx2sturgis]

Why spend money to cool the entire "room" when I'm the only one in it?   Of course there would still be a need for ventilation, but not climate control.

When camping/boondocking, my main problem with being in the heat is when I'm trying to sleep, and if you could figure out a way to just cool the mattress or the blanket...this would go a long way towards comfort. A simple wet towel or misting spray bottle of water helps a lot, unless you camp in very hot, humid areas.

During hot days I usually limit my activity, sit in some shade, or just go for a motorcycle ride.

 

[itsmeagain]

..my main problem with being in the heat is when I'm trying to sleep..

I agree 100% and the thought of running the coolant through the blanket was a consideration and definitely still on the list.  I can just stay out of the van during the day.

..unless you camp in very hot, humid areas.

[img=505x474]https://s-media-cache-ak0.pinimg.co...094784--florida-funny-florida-humor.jpg[/img]

 

[tx2sturgis]

If you imagined that you could pilot a hurricane, and needed to land, doesn't Florida look like a decent runway?

 

[jonsun]

its been so hot in ohio that I cant be outside for more than an hour. by then my eyelids are raw from wiping sweat and my shirt saturated.

I cant imagine florida

 

[itsmeagain]

If you imagined that you could pilot a hurricane, and needed to land, doesn't Florida look like a decent runway?

Hah!!   You know I never thought of it like that...      who could blame them, right?!?

its been so hot in ohio... I cant imagine florida

You know..  I find sometimes it can be even more brutal in states that may not be equipped to deal with the heat on a constant day to day basis.
I remember summers in New York that were absolutely unbearable, and unlike Florida, the homes weren't designed to combat the heat, and many without A/C!  That was a long time ago though.

Hang in there..  Ohio should have beautiful weather in a few short months.

 

[jimindenver]

On the A/C unit listed the 336/400 watt rating is not its running and starting watts. That is the ratings for low and high cooling settings. The surge although instantaneous if you have enough power is certainly higher than 400w. I can run the A/C off of a grp 27 marine battery if the solar there to provide the power. On the other hand my 800/1000 watt inverter generator can not even start my 5000 BTU A/C rated at 446w running. I could add a start capacitor but for now I do a modified hi-bred set up that can pull the surge from the batteries and then the generator runs it just fine.

That surge is serious enough that it toasted a cheap 3000/6000 watt PSW inverter in the initial testing of running the A/C. Trying to start it without the solar threw my old 8-D starting battery for a loop too. It could handle three 1 minute runs of a microwave pulling 1375w but it couldn't start that A/C. You can't see the surge on a killawatt or multimeter when you have enough capacity. Let the capacity be short and the compressor will struggle to start. That is when you will see the amp draw jump up to 120a and it will eat your battery if the compressor doesn't start. That also means you need more battery to run it all night than you think unless you plan on having it run full out and not cycling. Then you can say once started it takes this many Ah's and that is the capacity I need.

To understand how much solar you need to run things without dropping the voltage of the battery, you have to think of a solar panel as a micro generator. A 300 watt panel would generally be considered the limit of a 20 amp charge controller. That is a PWM standard and caused the MPPT brand I use to use to derate their 20 amp controller to 275w because 300 watts exceeded 20 amps and caused heat issues. So a pair of 300w or better panels can easily produce 40 amps of raw power out of the controller during the peak of the day. The A/C draws a peak of 400w and 400w is the limit of a 30a controller. So you have 40 amps of output and 30 amps plus inverter losses as a load. Make the panels tilt, turn the truck every so often and you will be able to start it sooner and run it later than with flat mount.

 

[John61CT]

So with the very high startup surge, you need a very solid expensive high-amp inverter to run the A/C.

A list of known good ones paired with the A/C unit they're running would be helpful.

Rather than also carrying an oversized gennie for the same reason, don't run the A/C directly off that, just use all its capacity to pump as much 14V charge as possible into the bank, (much) faster than the inverter + A/C is pulling energy out.

Ideally the bank is LFP, maintaining steady high voltage levels under heavy load. Also keeping very high CAR even when SoC is high.

The bank "buffers" the high-amp startup spikes so the genny doesn't get overloaded.

Solar's job now is to reduce genny run-time as much as possible, allow user to have a little leeway in choosing when to run it.

 

[IGBT]

Here is our setup.  We are running A/C off the sun during the day every day here in eastern Washington where it has been around 95 degrees at noon.   Fortunately when the sun goes down the outside temps drop like a rocket, from the 90s down to near 50 degrees by midnight.

A/C:  6000 BTU Danby window unit, draws about 600 watts when compressor is running
Batteries:  Four Lifeline 125AH 12V AGM GPL31XT wired in series parallel for a 24V system.
A Vanner Equalizer pulls off 12V at up to 60amps for things that need 12V like fans and lights.
Inverter:  Magnum MSH4024 24V input 4kW pure sine output with 6kW output while sharing load with generator
Solar:  Four 270 watt panels VOC about 35V, wired 2 series 2 parallel for 70V at about 15 amps coming down 10 AWG wire
Solar Charger:  Midnite Classic 150 MPPT charger rated up to 150V solar input 96 amp max output to battery bank of 12V to 48V. 

For our 24V bank and solar we see about 30 amps coming in when absorption charging around 28.8V at noon sun.  This is about 900 watts and is enough to run the ~600 watt air conditioner and put a few amps into the batteries at the same time.   I usually do not turn on the air conditioner until about 11am at which time the early morning sun has brought the batteries back up from ~80% to around 92%.   With the additional trickle they are usually at 100% by 3pm while the A/C is running and stay at 100% until about 4:30pm when the sun starts to drop below about 700 watts input to the panels.   I then either use the generator a little bit or just bump the A/C up a few degrees so it is not on constantly.  We use A LOT of laptop power and TV power in the evening so I try and save the battery juice for that.   Normally we don't need the A/C past 7pm and the RV pods stay about 72 degrees inside during the evening and are around 68 degrees in the morning when it is 55 degrees outside.

With two more batteries and two more panels I could go 100% solar A/C all the way until 8pm every night while still binge watching Game of Thrones until 10pm and making a 10 cup MR. Coffee pot in the morning.   Hello Amazon?  Can you ship me some more panels?

 

[tx2sturgis]

IGBT:

That's an impressive setup.

Do you have a dollar figure for all of the major pieces, (panels, electronics, batteries, genset), so we can get an idea how much investment is needed? 

Not including loads other than the AC unit.

And how many square feet of roof panels....approximately.

I'm gonna guess you have $3000 to $5000 in it.

Our truck APU's usually run in the $5000 to $8000 range.

 

[itsmeagain]

You guys are so great at taking big concepts and break them down for us less experienced..  and I know you have to do it over and over and over again with each new "Will this setup work?" type of post.
Your never-ending patience does not go unnoticed.

Just a quick question about those wattage readings so I can spot B.S. next time before posting about a unit:

On the A/C unit listed the 336/400 watt rating is not its running and starting watts. That is the ratings for low and high cooling settings. The surge although instantaneous if you have enough power is certainly higher than 400w...

Understood, and to be honest "400" took me by surprise as the surge wattage, even with my inexperience, but..  this was the verbiage I was basing my "336/400" numbers on. Is there something in this review that hints at the fact that the surge is probably well over 400?   ..or do you think this guy was just being less than truthful about what he was reading on his kill-a-watt device:

[font=Verdana, Arial, sans-serif]Questionably Accurate Amazon Review:

[/font][font=Verdana, Arial, sans-serif][font=verdana, arial, helvetica, sans-serif]So here are the four readings for you. I used a devise called a Wattsup Pro to measure. This device is an inline power monitor. Fan only Low 57.2 Watts, Fan Only High 60.3 Watts, Low cool w/ compressor 324 Watts and surprisingly High cool w/ compressor 336 Watts. So what that tells me is the fan low versus high shunts some of the power through a resister. Very little difference between low and high 3Watts Fan and 12Watts difference with the compressor. I will likely no longer run the unit on low to save energy again. Hope this helps. FYI during start up is did reach about 400 Watts on the meter. Not really the inrush power but gives you some idea of start up demand if you are planning a generator to run the unit. This is likely far more info than you needed. The unit also has what looks like a GFI plug with resets. It could just be a circuit protector.[/font][/font]

I didn't want to just repost the same quote from the original post..  so I've underlined the statements that caught my attention and created confusion for me.

Again, I'll take Jim and John's word over any random Amazon review..  just want to learn how to spot these inaccuracies so I don't waste peoples time posting about junk A/C's and impossible expectations.

 

[IGBT]

Yes, these are the ballpark prices we paid for the stuff:

Magnum MSH4024 24V 4kW inverter:  $1700
Midnite Classic $150 MPPT solar charge controller:  $600
Vanner Equalizer 12V 60amp:  $250 (new old stock on ebay)
270 watt LG solar panels: $200 each, $800 total with shipping.
Lifeline GPL31XT 125AH 12V AGM batteries $340 each with free shipping ($1360)
Danby 6000 BTU A/C  $120 from Costco.

So right at about $5,000 after adding in some costs of wire and breakers/fuses.

But it is quality stuff.  And soooo nice to use.  I haven not even opened the battery compartment in a year.   The Midnite Classic came with a Whizbang junior monitor which is a fuel gauge and meter for the battery usage.

Everything just works.

Oh, and the four panels take up about 60% of our roof space. About 10 feet by 6 feet.

 

[tx2sturgis]

Ok thanks, what is the approximate square footage or dimensions needed for the 4 panels on a roof?

That must be on a large van or a trailer?