Portable vs. Window AC...the never ending debate

[pete42]

Never had a portable unit just the factory ones and I did use a window AC in one old trailer on a trip from Ohio to California
back then 1967 folks said the trip would bounce the compressor around so much it would not work, well work it did and very well

reading the one tube vs two tube portable AC units and thought about a how a car AC works
in the NORMAL position it draws outside air to be cooled in the MAX setting it draws the air from inside the car.
I have found that the AC aeems to work less when the inside or max position is selected after the inside air has been cooled.

I would think the same would be true with a dual hose portable AC
if you could start out drawing air from outside then when the inside gets cool use the inside setting.

Trying to cool down a 100 degree trailer by drawing the inside air only seems to me it would take a lot longer time than outside/ inside one.........

so there you have it get what you want window, roof, or portable all work some better than others
if you are like me what ever you get someone will think you made the wrong choice.............
to them just smile and say "you could be right" while thinking "just go away".


pete

[Wolfscout]

so there you have it get what you want window, roof, or portable all work some better than others
if you are like me what ever you get someone will think you made the wrong choice.............
to them just smile and say "you could be right" while thinking "just go away".


pete

That pretty much applies to everything we do with our trailers in customizing. What works for me might not for another.
I don't really care to hear "what I should have done" LMAO.

[Tdcamper64]

The outside air I spoke of in the 2 hose version is used to cool the unit and then blown out side through the hose.
If you use 1 hose the conditioned air from inside is exhausted and is then replaced by outside, unconditioned air leaking in to the trailer.
The conditioned air is always drawn from the inside of the trailer, each unit has 2 exhaust and 2 intakes.
This confusion about how the portables work is why most are returned or at least disapointing to the unaware consumer.

[pete42]

The outside air I spoke of in the 2 hose version is used to cool the unit and then blown out side through the hose.
If you use 1 hose the conditioned air from inside is exhausted and is then replaced by outside, unconditioned air leaking in to the trailer.
The conditioned air is always drawn from the inside of the trailer, each unit has 2 exhaust and 2 intakes.
This confusion about how the portables work is why most are returned or at least disapointing to the unaware consumer.

I think I understand:
the (duel) 2-hose unit draws outside air to be cooled through one hose and the hot exhaust air is sent back out the other hose
while the (single) 1-hose unit the air to be cooled is the air inside the trailer and the hot exhaust air is sent out the single hose

sounds feasible no wonder it takes so long for a 100 degree trailer to cool using the single 1-hose AC unit.
but once cooled it would not have to work as hard to keep it cool inside whereas the duel 2-hose unit
would always be cooling the hot outside air.

which brings up another question if both hoses on the duel 2-hose unit are near each other would not the hot exhaust air be drawn
back into the trailer through the air intake hose?

If so you would have to make sure the exhausted air is directed away from the intake air nozzle.

sounds like a lot of work when a bucket of ice and a fan would work...................well maybe not.

pete

[Partsman]

the (duel) 2-hose unit draws outside air to be cooled through one hose and the hot exhaust air is sent back out the other hose
while the (single) 1-hose unit the air to be cooled is the air inside the trailer and the hot exhaust air is sent out the single hose

Not quite. Both systems pull air from inside the trailer to be COOLED.

The two hose system (and window units) pull outside air to be HEATED and vented outside.

Single hose portables pull your freshly cooled air back from inside the trailer to heat and vent outside.
That creates a vacuum in the trailer so hot air leaks back in any ware it can.

The one hose unit is less efficient but if you are plugged into a 30amp plug and paying a flat nightly fee it really doesn't matter.

[Tdcamper64]

Correct, if not considering power useage then the diffrence is in the effective BTU's.
This is most noticed when it takes so long for a seemingly large air unit to cool the trailer down.
In my experiance cooling a CT in the Georgia heat, it's half the time to cool if properly vented (inlet and exhaust).
Around mid summer thats a huge payback for the little work, of setting it up well.

[pete42]

the (duel) 2-hose unit draws outside air to be cooled through one hose and the hot exhaust air is sent back out the other hose
while the (single) 1-hose unit the air to be cooled is the air inside the trailer and the hot exhaust air is sent out the single hose

Not quite. Both systems pull air from inside the trailer to be COOLED.

The two hose system (and window units) pull outside air to be HEATED and vented outside.

Single hose portables pull your freshly cooled air back from inside the trailer to heat and vent outside.
That creates a vacuum in the trailer so hot air leaks back in any ware it can.

The one hose unit is less efficient but if you are plugged into a 30amp plug and paying a flat nightly fee it really doesn't matter.

now I'm confused, (easy to do) the portable units have both a heat and a cool function?
I am going to have to check one out for myself I have owned several window units over the years and I don't remember any of them having a heat function.
but I'll do some more checking thanks for the reply.

pete "old and confused"

[Partsman]

now I'm confused, (easy to do) the portable units have both a heat and a cool function?
I am going to have to check one out for myself I have owned several window units over the years and I don't remember any of them having a heat function.
but I'll do some more checking thanks for the reply.

pete "old and confused"

No most of them don't have a heat function.

It is not possible to make cold. You have to remove the heat from something to cool it off.
Air conditioners remove some of the heat from the air to make it cool.
That heat has to be vented outside or the room would never get any cooler.

[bigbendhiker]

Other considerations regarding the a/c question;

I was recently looking at WalMart and Home Depot for air conditioners. They both had 5000 BTU window units (WalMart's was actually 5050) for $99. They are very small (physically) especially the one at Home Depot. It was an LG. From what I've read on these forums a 5000 BTU window unit will easily cool an insulated trailer. I've also read that the portable units don't seem to be as efficient and require a larger BTU rating to adequately cool a trailer.

The same Home Depot had several portable units. The smallest was 8000 BTUs and priced at $279. It was also at least 3 to 4 times the physical size of the window unit. Given the limited space in most trailers and the price difference it seems to me that the window unit is a no brainer if you can make it work in your trailer design.
Now I suppose if you only need a/c for a month or two out of the year or if you need the ability to have open access to the back of the trailer then you may wish to have a portable unit.

As Pete42 said to each his own.

And the debate goes on................

[Prem]

My inexpensive and basic solution for very hot trailer camping: Wearing a wet cotton shirt and cotton hat, cold beer in hand. Fashion is out the window. "Axsk" me if I care.

Dry by sundown or one can get cold fast.

[Wolfscout]

The whole "pulling outside air in to replace the "vacuumed" air sounds funny to me.
If that's so the point would be mute on a thermostat ran AC. and Mine rarely cuts on and off frequently once the camper has reached the desired temperature.

But then... who cares as long as mine works for me and ya'lls works for you. funny how perspectives and opinions can vary.

[bigbendhiker]

My inexpensive and basic solution for very hot trailer camping: Wearing a wet cotton shirt and cotton hat, cold beer in hand. Fashion is out the window. "Axsk" me if I care.

Dry by sundown or one can get cold fast.

Hey, I hear ya. Sounds good...............most of the time.

I live near Dallas and the first summer that my sons went to Boy Scout summer camp it was at Camp Cherokee near Athens Texas. That is East Texas, pine trees, in June where high humidity is the norm. I still have nightmares from trying to fall asleep in a stupid canvas wall tent at 10:30 - 11:00 pm. I remember lying on a cot sweating like some kind of pig. It was still north of 90 degrees after 10:00 and the humidity must have also been above 90%. If I am ever in anything like that again I want a/c.

[Prem]

I've frequently trailer camped on asphalt in campgrounds when it was 100 to 112 degrees (Whiskeytown Reservoir, outside of Redding, CA) using only the wet shirt and hat method, no AC. However the humidity out west here is too low to measure when it's that hot. I've lived back east when it was 95* and 95% humidity in the summer. The wet shirt method does not work unless a fan is blowing on you. Summer on the Gulf coast or the East coast in the hot season is not the best time of year to be outdoors. Out west it's the optimum time to go camping. It's too windy, rainy and cold or snowy the rest of the year. Some years even May and September can be bad. When they are good, camping is really good.

[aggie79]

Pete,

I'll give a shot at trying to explain the difference. Think about a typical home air conditioner system (not a window unit). There is an outside "box" that contains a compressor and condensing unit. Inside the house there is a "box" that contains an evaporater and air handler (fan.) For each of the two "boxes" there is a separate air flow path. For the outside box, air comes into the box, goes through the condensor (to cool it and the compressor), and exits the box. For the inside box, the air to be cooled/conditioned (return air) enters the box, is pushed by the air handler across the evaporator coils to cool the air, and is "blown" through the ductwork to various grills (vents) through out your home. The indoor air path is actually a "loop" in that it is recirculated.

A typical window unit and a two-duct portable unit work the same way as the home air conditioner except that the two boxes are combined into one box. There are still two separate air flow paths.

In a one-duct portable unit, there is no separate intake for outside air to cool the compressor and evaporater. The air used to cool the compressor and evaporater is "taken" from the return air that is being "sucked" back into the air conditioner to be re-cooled and re-distributed. This partially conditioned air (previously cooled air) is then used to cool the condensor and compressor and then is exhausted through the one duct to the outside. For this reason, the one duct portable is less efficient because not all of the interior air is being recirculated.

Hope I didn't confuse things.

Take care,
Tom

[Glenlivet]

Thanks Tom. It's as you say, two air systems, one box. Two 'radiators', one in each internal system box. One evaporater rad (gets cold), one a condenser (gets hot), connected by pipes and a pump that circulates coolant between them.
The evaporater box takes inside air, shoves it through the evaporater where it gets cooler, and it exhausts it back into the interior.
The condensor box draws in outside air, shoves it through the condenser where it takes on the heat that was in the evaporater (ergo the C/T), and exits the air back outside, hotter than it was before. The air doesn't mix unless the A/C has an 'open' duct position so that some of the inside air is exchanged with outside air and thus 'freshened'. Of course this makes the A/C a bit less efficient. When it's not mixing it's the same as 'Max A/C.'

The single hose versions draw inside air in just the same way, cools it through the evaporator, and exhausts hot air from the condensor to the outside, but the air that supplies the hot condensor also comes from inside the C/T, so that means there's going to be a continuous low pressure condition within the room (C/T) and the air to replace the hot exhaust air must be constantly replaced by outside air getting in from wherever it can. This makes the single hose versions less efficient.