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I am always fantasizing about having a energy efficient air conditioner for van life, anyone seen any concepts in tech news or anything?

eXodus said:
Like this night - started out with 85 - turned on the A/C - ran it for about 2 hours - then it cooled of enough so that I didn't had to use anymore.

The alternator is my backup power source of charging. I drive every other day anyhow. I hardly stay more then 48 hours in one place.
When we got into the summer - just hanging out somewhere with power or driving somewhere cool.

I don't stay somewhere where the nights stay above 80.



My express Van got the heavy duty A/C option from the passenger Vans- it does a fabulous job at keeping the box cool at idle. I've used it a few times during the day to cool of. Just gobbles a lot of fuel.
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Totally different scenario. I'm using my minivan camper as a beach beater year round for day trips and over night / long weekend trips, also in Florida. Up to 95 F days, 85 F nights, high humidity, no power hookups (staying right on the beach).

I don't even try to use a solar powered AC, it won't last long enough to make a difference.

Guten Tag.
 
GSXR1000 said:
i would like to cut this into 2 pieces and and copper line set and make it a split unit, for the RV. wish it had Heat pump mode
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go out and complain a little at the Chinese manufacturer and they may develop what you want. Pretty responsive those folks.
Half of what people suggest at this discussion board is build a few months later.
 
Everyone is different but if I run the air for 2 hours and then turn it off the rest of the night it is going to be humid AF inside that van. Open the vent and you let the hot back in. Same result. Unless you are in the high desert that isn't going to work. If you are in the desert you don't need air at night anyway. Every area will be different. Some dude trying to run air off his solar in SE FL is going to have different results that the guy @8kft in a dry mountain top.

That is the issue with comparing solar setups, air conditioner use, and just about everything else. People's thresholds are different as is the environment. You got one guy saying he runs his a/c off solar without issue but he lives at 80 degrees and 85% humidity. Its like talking with my grand mother and asking how much air conditioning she uses. She opens her windows when it is 90 outside and you can cut humidity with a knife. Maybe he lives on top of a mountain in a dry area. The guy living in Louisiana trying to cool his rig has nothing what so ever in common with this even though they are doing the same thing.

Then you have me who likes it at 75 during the day and below 70 all night, including the time when the compressor is cycling and temps rise. So we use air or at least the dehumidifier function almost everywhere.

Personally when I think of air conditioner use, I'm not looking to make my space marginally better than the outside. I'm looking to make it feel like a house or RV. Comfortable and for most people 77 or lower with low humidity. If you're in an area where temps drop below 7o and don't have a lot humidity at night then you're good. If you're in a hot area that is humid then it will be much harder.

We can do it for about 12 hours (evening / night 75 and 67 at night when sleeping in the hottest / humid climates) which is great but it requires supplemental charging because even with 800 watts on the roof it isn't nearly enough to refill 400ah @24v.

YMMV because every area is different and every person has different requirements / thresholds for comfort.
 
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Vanconversion21 said:
Everyone is different but if I run the air for 2 hours and then turn it off the rest of the night it is going to be humid AF inside that van. Open the vent and you let the hot back in. Same result. Unless you are in the high desert that isn't going to work. If you are in the desert you don't need air at night anyway. Every area will be different. Some dude trying to run air off his solar in SE FL is going to have different results that the guy @8kft in a dry mountain top.

YMMV because every area is different and every person has different requirements / thresholds for comfort.
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Everyone is different.

I'm perfectly fine with 80 during the day and 78 during the nights. Even with high humidity. As soon the temperature goes below 75 in Florida I open the windows in Florida and turn the roof fan on in my Van and sleep perfectly fine.
 
OnTheRoadAgain said:
Yep. There are a few here who will make a point of showing you the size of their ego, rather than focus on the topic.
Just happened to me in one of my recent posts.
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You are so right. https://diysolarforum.com/threads/best-dc-to-dc-charger-for-smart-alternator.21547/post-253864
OnTheRoadAgain said:
That said, great forum, mostly great people with a ton of knowledge and willing to help. (y)
As my brains diminish with age, I'm fighting to make sure my ego diminishes proportionately.
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I agree, as I get older, I forget more than I remember.
 
Zwy said:
I don't believe what Amazon says, I got specs right off the link to Midea where it says, Full Specifications. https://www.midea.com/us/Air-Condit...8,000-BTU-U-shaped-Air-Conditioner-MAW08V1QWT
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I got the 8000 BTU Midea here - what do you want to know?

Following numbers are measured at the plug.
The fan needs about 130w on high and about 40w on low. The minimum when the compressor runs is about 260w (including the Fan on low)

The highest I've ever seen it was drawing about 780w. The compressor is fully variable and ramps up and down all the time. The Fan has 4 speeds (low, med, high and "turbo") I only call it - Turbo, there is not button for that - when you got the Fan on Auto it blows faster then "high" and only runs a limited time when it's very hot, it's a like an overdrive.
 
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Zwy said:
You are so right. https://diysolarforum.com/threads/best-dc-to-dc-charger-for-smart-alternator.21547/post-253864

I agree, as I get older, I forget more than I remember.
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eXodus is incorrect about the functioning of a Midea 8000 BTU u shaped AC. I've owned one since the first of April 2020. Had to wait two months to receive it as Midea was just beginning production. I knew they were coming because of https://www.energystar.gov/productfinder/product/certified-room-air-conditioners/results. Testing is done in advance of product release. There should be a couple of more brands on the market about now. Using a Kill a watt, the lowest wattage I've seen with the compressor running is around 98 watts.. A good way to tell if the compressor is running, is to measure the incoming/return air temp and the outgoing air temp. If there is a delta T, then the compressor is running. The max watts is indeed at least 750 watts. PDF explaining the working of mini-splits. https://www.aceee.org/files/proceedings/2016/data/papers/1_836.pdf Some of that info is from this PDF. https://www.ahrinet.org/App_Content...HRI Standard 210.240 with Addenda 1 and 2.pdf
For the last three years I have been using a LG - LW8019ER to both cool and heat my north FL home. Now I use both the Midea and the LG to cool the home. I use a CT switch to turn on the LG when the Midea is using more than 420 watts. Both ACs working at the same time drive the temp down so the Midea will get into a more efficient(lower frequency) range temp. Then I shut the LG off and the Midea works alone until 420 watts is again reached. LG turns on and the cycle repeats. The 8000 BTU LG only uses 650 watts to produce its max BTU, so at some point more efficient than the Midea. So probably when the Midea reaches a frequency of 60 cycles or so, it is no longer more efficient than the LG. At 6:55 eastern time, Midea, by itself, outgoing air 56.1F 84%RH, return air of 72.5F 63%RH, so a delta T of 16.4 F degrees while using 98 watts. Outdoor temp around 70 F, RH 83%. https://www.wunderground.com/wundermap I've posted elsewhere in the forums a couple of PDFs about the frequencies of inverter window ACs.
 
rcrracer said:
eXodus is incorrect about the functioning of a Midea 8000 BTU u shaped AC. I've owned one since the first of April 2020. Had to wait two months to receive it as Midea was just beginning production. I knew they were coming because of https://www.energystar.gov/productfinder/product/certified-room-air-conditioners/results. Testing is done in advance of product release. There should be a couple of more brands on the market about now. Using a Kill a watt, the lowest wattage I've seen with the compressor running is around 98 watts..
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Maybe I'm not completely incorrect - maybe we a measuring different temperatures and lead scenarios. :)

I have a very cheap power meter. 750w or 780w - that's within the realm of measuring error and cable resistance.

How do you get it down to 98w? Cooling against 70 degree air? I got my setpoint at 75, so usually when the outside gets to about 85 outside the midea starts running the compressor and then I see 200w or more.
 
Its says CEER 15 BTU/H/Watt right in the specs. That's 533 watt / h in average.

CEER test conditions: outside temperature of 95F, inside target temperature/thermostat setting of 80F and a specific inside humidity of 50%.
 
McCarthy said:
Why would ANYBODY pump warm outside air into a car when the AC is running?! That's like driving around with open windows. That's called common sense, and your assumption makes zero sense. This thread is about air conditioning or at least cooling down a vehicle while the engine and OEM AC is off, on battery power.
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I do it nearly every day in the summer and I think lots of others do as well - All modern cars have the option to either cool inside air (recirculate) or outside air and for a variety of very good reasons. When I get into my car parked out in the sun on a 90 or 95 degree day, it's often 130 or 140 degrees inside the car. Start it up, switch to outside air and the car will cool down much faster using the 90 or 95 degree ambient outside air than trying to deal with the 130+ inside air. 10 minutes or so later, switch it to recirculate and finish getting it down to 70 or 75 degrees

For those of you who smoke inside a space as small as a car, often with your kids in the backseat (now, why anyone does that is an even bigger question, but you know who you are . . . . ) I would HOPE that you are cooling outside air ALL THE TIME, getting that poison out of your car and giving your kids with their still forming lungs a chance at a healthy life later on - Please, NEVER switch it to recirculate . . . .

Don
 
Alphacarina said:
I do it nearly every day in the summer and I think lots of others do as well - All modern cars have the option to either cool inside air (recirculate) or outside air and for a variety of very good reasons. When I get into my car parked out in the sun on a 90 or 95 degree day, it's often 130 or 140 degrees inside the car. Start it up, switch to outside air and the car will cool down much faster using the 90 or 95 degree ambient outside air than trying to deal with the 130+ inside air. 10 minutes or so later, switch it to recirculate and finish getting it down to 70 or 75 degrees

For those of you who smoke inside a space as small as a car, often with your kids in the backseat (now, why anyone does that is an even bigger question, but you know who you are . . . . ) I would HOPE that you are cooling outside air ALL THE TIME, getting that poison out of your car and giving your kids with their still forming lungs a chance at a healthy life later on - Please, NEVER switch it to recirculate . . . .

Don
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Not the same. Your air gets pushed through the AC coils and cooled down before the air gets into the cabin.

My fans would push warm air from the rear cabin vents into the cabin without cooling it down, AND working against the AC. That was the assumption from another member here and makes no sense.

Your reply is totally out of contest.
 
I always want ventilation. There is definitely such a thing as being too tight, especially in a fairly small space. Insulation is a very good thing, but ventilation is necessary also.

When I worked, one of my accounts was a school which we had retrofitted for energy efficiency. One of the strategies was to limit outdoor air intake as much as possible .... schools typically had a requirement for a very large % outdoor air. We installed CO2 sensor in every classroom and only introduced outdoor air when the CO2 levels indicated the classroom was occupied.

One of my tasks was to periodically calibrate those sensors ... I had a tool for doing that.

So .... I went out to my van to eat lunch and of course brought my tools with me. It was winter, so I had the windows up .... and decided to monitor the CO2 level. I was absolutely amazed at how bad the CO2 level got after only being in the van for about 10 minutes. It changed my whole outlook on ventilation in a vehicle .... I think there should be a regulation that requires a CO2 sensor in a vehicle.
Can you imagine how high the CO2 levels get with 3 or 4 people in a car and the ventilation set to recirculate air ... probably explains why people go to sleep and run off the road.

In my camper, I always have the vents open at least a little no matter what the outdoor temperature is.

Maybe this is out of context too.
 
Someone doesn't get the idea of those one hose portables exhausting room air.. they even pass that air thats being blown out through the drip pan area to evaporate them so they don't need emptying as often.

But all that aside There is a guy on YT that did a van camper build. He used a window unit and built a split unit (A/C only obviously). It was pretty ingenious and inexpensive. I am going to try to find that video...
 
Heat exchanger vent. The idea is to bring outside air to temperature of inside and vice versa while exchanging air.
Here's a commercial unit; I would expect someone to DIY one.

www.rvupgradestore.com

BAL 25110 Air-Port Fresh RV Air Exchanger

The BAL 25110 Air-Port Fresh Air Exchanger is a permanently installed RV air exchanger that can remove stale air from the interior and replace it with fresh air from outside
www.rvupgradestore.com
 
Hedges said:
Heat exchanger vent. The idea is to bring outside air to temperature of inside and vice versa while exchanging air.
Here's a commercial unit; I would expect someone to DIY one.

www.rvupgradestore.com

BAL 25110 Air-Port Fresh RV Air Exchanger

The BAL 25110 Air-Port Fresh Air Exchanger is a permanently installed RV air exchanger that can remove stale air from the interior and replace it with fresh air from outside
www.rvupgradestore.com
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That's what I did, but much better.

Your suggestion
Watts: 7.5
Amps: .625
Noise: 51 dBA
Air Flow: 76.5 CFM
Life Expectancy: 140,000 hours
Price: $307.00

My solution
Watts: 2.2
Amps: .018
Noise: 25.1 dBA
Air Flow: 140 CFM
Life Expectancy: 150,000 hours
Price: $27.80


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Amazon.com: Noctua NF-P12 redux-1700 PWM, High Performance Cooling Fan, 4-Pin, 1700 RPM (120mm, Grey): Computers & Accessories

Buy Noctua NF-P12 redux-1700 PWM, High Performance Cooling Fan, 4-Pin, 1700 RPM (120mm, Grey): Case Fans - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
 
McCarthy said:
That's what I did, but much better.

Your suggestion
Watts: 7.5
Amps: .625
Noise: 51 dBA
Air Flow: 76.5 CFM
Life Expectancy: 140,000 hours
Price: $307.00

My solution
Watts: 2.2
Amps: .018
Noise: 25.1 dBA
Air Flow: 140 CFM
Life Expectancy: 150,000 hours
Price: $27.80





Amazon.com: Noctua NF-P12 redux-1700 PWM, High Performance Cooling Fan, 4-Pin, 1700 RPM (120mm, Grey): Computers & Accessories

Buy Noctua NF-P12 redux-1700 PWM, High Performance Cooling Fan, 4-Pin, 1700 RPM (120mm, Grey): Case Fans - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
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Details of the reverse-flow heat exchanger you fabricated? ;)
 
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