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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?

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


1619663310958.png


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? ;)
 
Altide8 said:
I ordered this unit. It took about 3 weeks to get here. I should have it installed on my van this weekend. The compressor is actually 12v so I am happy with that. I know of read about some people that got "12v" units that just had a boost converter for a 24v compressor. I am still trying to figure out what modes and such it has. I think it is variable speed.

Factory Cheap Portable Truck Radiator 24v Dc Electric Car Air Conditioner 12v Excavator Construction Vehicle Ac Conditioner - Buy 24v Dc Electric Car Air Conditioner Universally 12v Car Vehicle Air Conditioner,Truck Air Conditioner Parking Air Condit

Factory Cheap Portable Truck Radiator 24v Dc Electric Car Air Conditioner 12v Excavator Construction Vehicle Ac Conditioner - Buy 24v Dc Electric Car Air Conditioner Universally 12v Car Vehicle Air Conditioner,Truck Air Conditioner Parking Air Conditioner Vehicle Electric Air Conditioner...
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Any updates on this?
I was thinking about buying this ...unless it turns out not to work as advertised

Please keep us (me) updated on this one please.
 
Hedges said:
Details of the reverse-flow heat exchanger you fabricated? ;)
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That unit tries both, bringing in fresh outside air, and exchanging heat / cold air. Perfect oxymoron in my book.

Guess how well that heat exchanger works with 7 watts and 80% claimed efficiency.
 
Also... 2 reviews... last one is 6 years old... not available anymore anywhere. Guess why.


1619665839242.png
 
OnTheRoadAgain said:
Any updates on this?
I was thinking about buying this ...unless it turns out not to work as advertised

Please keep us (me) updated on this one please.
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I haven’t had a chance to get it charged yet. Everything is wired up and ready to go. I just have to visit my brother who has the vacuum pump and ac lines to charge it.
 
eXodus said:
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.
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I have the Midea set at 74 F and use a kill a watt to measure watts. I've posted elsewhere PDFs about how mini splits are tested. The reason you are seeing 200w are more is due to the higher outside temperature. The inverter window ACs must have an outside thermistor just like the mini-splits. Last summer when I used my LG to drive the temperature down so the Midea wouldn't use as many watts, I was only able to get the Midea down to 150 watts. The outside air temperature was too high to allow any lower watts. I'm cooling a 1450 sq. ft. in FL with the Midea and sometimes the LG. One reason I chose the LG was no secondary sensor(thermistor). https://www.storeitcold.com/wp-content/uploads/2021/02/AC-Selection-2021B.pdf I think inverter technology HVAC can be made more efficient by lying to the outside thermistor as to what the ambient temperature actually is.
 
rcrracer said:
I have the Midea set at 74 F and use a kill a watt to measure watts. I've posted elsewhere PDFs about how mini splits are tested. The reason you are seeing 200w are more is due to the higher outside temperature. The inverter window ACs must have an outside thermistor just like the mini-splits. Last summer when I used my LG to drive the temperature down so the Midea wouldn't use as many watts, I was only able to get the Midea down to 150 watts. The outside air temperature was too high to allow any lower watts. I'm cooling a 1450 sq. ft. in FL with the Midea and sometimes the LG. One reason I chose the LG was no secondary sensor(thermistor). https://www.storeitcold.com/wp-content/uploads/2021/02/AC-Selection-2021B.pdf I think inverter technology HVAC can be made more efficient by lying to the outside thermistor as to what the ambient temperature actually is.
Click to expand...
how would lying to outdoor sensor make it more efficient?
 
rcrracer said:
I have the Midea set at 74 F and use a kill a watt to measure watts. I've posted elsewhere PDFs about how mini splits are tested. The reason you are seeing 200w are more is due to the higher outside temperature. The inverter window ACs must have an outside thermistor just like the mini-splits. Last summer when I used my LG to drive the temperature down so the Midea wouldn't use as many watts, I was only able to get the Midea down to 150 watts. The outside air temperature was too high to allow any lower watts. I'm cooling a 1450 sq. ft. in FL with the Midea and sometimes the LG. One reason I chose the LG was no secondary sensor(thermistor). https://www.storeitcold.com/wp-content/uploads/2021/02/AC-Selection-2021B.pdf I think inverter technology HVAC can be made more efficient by lying to the outside thermistor as to what the ambient temperature actually is.
Click to expand...

My limited knowledge about A/C units tells - the higher the temperature outside - the higher the pressure in the system - the harder the compressor has to work - that's why you see higher power draw at high temperatures.

My stupid 13500BTU ON/OFF RV A/C units takes more watt when it's hot outside vs only warm.

This compressor is one speed, no fancy controls, no electronics, and when it's cooling against cool air - about 1000w - but when it's hot outside - it goes up to 1300w.
 
eXodus said:
My limited knowledge about A/C units tells - the higher the temperature outside - the higher the pressure in the system - the harder the compressor has to work - that's why you see higher power draw at high temperatures.

My stupid 13500BTU ON/OFF RV A/C units takes more watt when it's hot outside vs only warm.

This compressor is one speed, no fancy controls, no electronics, and when it's cooling against cool air - about 1000w - but when it's hot outside - it goes up to 1300w.
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that's a fact of preasure tempature relationship... not a sensor or anything else.. just what happens
 
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