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12v mini air conditioner?

NO AIR CONDITIONER ADDS HUMIDITY TO THE AIR…

Many reduce the humidity capacity of the air, raising the relative humidity reading… not the same thing. What happens is the air is cooled faster than the moisture can be removed, and you get moisture collecting on cooled surfaces… moisture that causes mold and mildew to form. The solution is have the fan cool less cold. Set temp higher, and never run on high cool in mild weather.
Well.

That's not really what he meant.

More that it doesn't run long enough to dry out the air, as you said, and as a result humidity increases. I don't know if "less cold" is the solution to humidity, but it is definitely for the condensation.
 
Was the portable unit a single pipe, or dual pipe exhaust?
Single pipe units, pump cooled air out of the space, creating a negative pressure in the space, sucking outdoor air and humidity back into the space… EXTREMELY inefficient, and uncomfortable.
Single, and I do very much understand that they are not efficient. But it was the easiest solution, and it does work. Helps that we are not really paying for the power. Can't put a roof unit on, as we need the low clearance, cutting a hole for a window unit was unrealistic, but modifying a screen for our many windows for a vent system was very possible.

For the vent, I keep a window close by cracked, and try to direct the air to the unit.

And "uncomfortable" is relative. It's most certainly more comfortable than having nothing.
 
NO AIR CONDITIONER ADDS HUMIDITY TO THE AIR…

Many reduce the humidity capacity of the air, raising the relative humidity reading… not the same thing. What happens is the air is cooled faster than the moisture can be removed, and you get moisture collecting on cooled surfaces… moisture that causes mold and mildew to form. The solution is have the fan cool less cold. Set temp higher, and never run on high cool in mild weather.
Thank you. Way to much misunderstanding of this.
 
I'm thinking I have to make something for next year at camp, the summers keep getting hotter. Maybe a $200 inverter compressor or the real high efficiency Pelletier modules just to give a little cooling breeze.
A very small water pump circulator and a homemade heat exchanger with 12V muffin fan and you can use evaporative cooling by drizzling water down a sheet with multiple holes; they did this 200 years ago in the southwest. We should be able to handle that fine with technology!?
 
The Midea U would be perfect... but there will be no cutting holes in this camper.
since you got new camper - the A/C unit is new. -You still get money for it.

I would sell it and buy a smaller roof RV A/C unit.
 
Single, and I do very much understand that they are not efficient. But it was the easiest solution, and it does work. Helps that we are not really paying for the power. Can't put a roof unit on, as we need the low clearance, cutting a hole for a window unit was unrealistic, but modifying a screen for our many windows for a vent system was very possible.

For the vent, I keep a window close by cracked, and try to direct the air to the unit.

And "uncomfortable" is relative. It's most certainly more comfortable than having nothing.
They certainly put out cool air, but the two pipe models are FAR better.
 
since you got new camper - the A/C unit is new. -You still get money for it.

I would sell it and buy a smaller roof RV A/C unit.

That's a plan... but those low profile units are SUPER loud. :(
 
They certainly put out cool air, but the two pipe models are FAR better.
If you can find one that weighs less than 50lb, post it. All of the ones I've seen that are two pipe are at least 75lb- which means that IF I wanted to take it out, it would be much harder.

It's funny that only +12k BTU coolers are dual hose. The all brag that you can cool more space with less power thanks to the condenser cooling air coming from outside. But if they are that much better, then a small 8000BTU unit would be a really good choice- it would be FAR more effective at cooling. One can wish.
 
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If you can find one that weighs less than 50lb, post it. All of the ones I've seen that are two pipe are at least 75lb- which means that IF I wanted to take it out, it would be much harder.
Really? I wasn’t aware they were different weights… just one is better designed.
 
Really? I wasn’t aware they were different weights… just one is better designed.
Our single hose one is less than 50lb. For our RV, weight matters. My next step will be to insulate the hose....

If I could figure out where the condenser cooler inlet is, I would make sure it got "clean" air.

Can't say that I really understand why a dual hose would be *that* much heavier- it's just internal ducting space on the housing that would transform the one we have. I suppose I could take it apart and build something, but not until later....
 
Does the one pipe unit heat?
Copper plumbing and valves for heat mode would add a few pounds
 
Does the one pipe unit heat?
Copper plumbing and valves for heat mode would add a few pounds
No. And I'm not sure how that's such a feature when you can get a small space heater that is quieter and more efficient at turning electricity to heat.
 
One way an air conditioner can add humidity back into air is leaving air handler blower running continuously after compressor cycles off due to temperature being reached.

The greater the air flow across the evaporator the better the efficiency at temperature reducing. This can result in area feeling like a cool damp cave as less humidity will be condensed from the rapid air movement across evaporator allowing little time for condensation of air moisture..

Many mini-splits and some regular central units have a dry mode that reduces air flow across evaporator by reducing blower speed when higher humidity is detected. This allows more time for humidity to condense on evaporator coils before air is ejected back into area.

Too large a BTU unit for a given area can be a bad thing. Temp is dropped quickly, A/C has shorter run time duty cycle and less humidity is removed from environment. If you live in Az. this may be a good thing. If you live in S. Fla. not so good.
 
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I don't think there is any such thing as an efficient Peltier cooling element. Only ones with large heat sinks to keep greater temp delta between sides.

It helps a lot having an endless supply of cooling water no matter which way you do a heat pump system.

The video doesn't talk too much about humidity. Removing humidity takes a lot of btu's. Once the high humidity is removed it takes less than half the power.
if you buy a TEC1-12715 module (a real one, that model designation is falsely printed on cheap modules often to defraud buyers :()

apply 15V to it and it will indeed be quite inefficient due to Joule Heating. an average module of that model would have resistance of approximately 0.8 Ohm.

apply 2.2V to it and it will still move a very noticeable amount of Joules across itself, while producing much less Joule Heating while still providing quite a bit of the Peltier Effect

it will still be less efficient than an average run of the mill compressor based refrigerant flow heat pump by a noticeable margin, in almost all comparisons between peltier type and refrigerant compressor type.
 
apologies in advance for rambling about Peltier,

operating a Peltier Module of 127 junction module with a temperature difference of beyond 10 degrees C will result in a large drop in efficiency. the answer is stacking.

(this is the 127 in TEC1-12715)

2.2V will do about 10 degrees C per module. stacking the modules on top of each other up to 4-5 layers results in continuous flow through all of the modules. confirmed with testing, not theory. past 4 layers the thermal conductivity is not really fast.

again, it will be less efficient than refrigerant type compressor heat pumps, but it will be much more efficient than shipping in ice ?
 
That's a plan... but those low profile units are SUPER loud.
you can get a 9000 or 11000 BTU roof unit in the high profile.


I think the profile has little todo with noise level. When you look at the specs - there are also high profile which are loud :p It's more like that one manufacturers low profile are loud.

 
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