Tearing out my cargo ac

[XR-duous]

Well this sucks! I spent a ton of time dialing this in so that it was sealed and worked well and hardly got any hours logged before the compressor failed. Now I have to tear it all out and start over. I can't think of a redesign that would make this any easier. Would be great just to slide in and out, but every unit is a different size.

[John61CT]

Units designed to handle bouncing around will last longer

[flboy]

Units designed to handle bouncing around will last longer

What makes a unit designed better to handle being bounced around? Just curious.

[John61CT]

Those designed for buses, RVs, marine applications etc

[Modstock]

Went through 3 A.C. units in our teardrop. The bouncyness broke the Freon lines every time.
Now we just use a fan.

I have one unit sitting here waiting to see if I can make some sort of swamp cooler out of it. Probably just hanging onto junk.

Sent from my H1611 using Tapatalk

[XR-duous]

When the compressor would kick on, it would sound restricted then it would shut off. I plugged it Into the garage after I pulled it and it was fine. Put it back in the trailer just to see.....works perfectly. Now I have no idea if I can trust it or not.

[flboy]

When the compressor would kick on, it would sound restricted then it would shut off. I plugged it Into the garage after I pulled it and it was fine. Put it back in the trailer just to see.....works perfectly. Now I have no idea if I can trust it or not.

Check your wiring to AC... maybe a voltage drop on a bad connection tripping the built in brown out relay (protects compressor from low voltage). AC's on houses will do that often (lights flicker, etc.) when compressor comes on if it is hard starting due to a low voltage (drop on Main breaker or contacts).

[aggie79]

Units designed to handle bouncing around will last longer

What makes a unit designed better to handle being bounced around? Just curious.

I don't want to get too far off topic, but the stresses of caused by "bouncing around" are minuscule compared to the normal operating stresses of an air conditioner - compressor vibration, thermal cycling, etc.

I have cleaned the coils several times on my travel trailer's Atwood air conditioner. Visually, there is very little difference in construction between that unit and the window unit I used in my teardrop. The RV unit has more sheet metal bracing, and the motor shaft of the blower and fan is a little larger in diameter (probably due to its much greater length), but the coils, refrigerant lines, and wiring are built and packaged the same as a window unit.

Back to the topic: I think Don "hit the nail on the head". Low voltage appears to be the culprit. What gauge wiring did you use to wire the trailer? Are there any other fixtures or appliances running on the same circuit as the A/C unit. How are you providing power to the CT conversion? It is by generator or campground pedestal? If the latter, they are notorious for not providing correct voltage (low voltage).

[flboy]

Units designed to handle bouncing around will last longer

What makes a unit designed better to handle being bounced around? Just curious.

I don't want to get too far off topic, but the stresses of caused by "bouncing around" are minuscule compared to the normal operating stresses of an air conditioner - compressor vibration, thermal cycling, etc.

I have cleaned the coils several times on my travel trailer's Atwood air conditioner. Visually, there is very little difference in construction between that unit and the window unit I used in my teardrop. The RV unit has more sheet metal bracing, and the motor shaft of the blower and fan is a little larger in diameter (probably due to its much greater length), but the coils, refrigerant lines, and wiring are built and packaged the same as a window unit.

Back to the topic: I think Don "hit the nail on the head". Low voltage appears to be the culprit. What gauge wiring did you use to wire the trailer? Are there any other fixtures or appliances running on the same circuit as the A/C unit. How are you providing power to the CT conversion? It is by generator or campground pedestal? If the latter, they are notorious for not providing correct voltage (low voltage).

I agree and that was the point of my question which was not answered. Based on my research and my personal experience over the years, the rooftop AC is only rooftop/RV centric specifically because the RV manufactures and Utility Trailer manufacturers all make standard 14 inch vent tops so an AC can be installed at the factory or aftermarket (assuming appropriate bracing) anytime without consideration of any other design aspect. It is simply the easiest thing to do, less costly from a labor perspective, a standard, and a very good use of space for large RV's. I have had them all apart before, and I see nothing different for the most part.. if things seem more robust, it is usually due to a 12,500 BTU unit being compared to a 5,000 BTU for instance.. Need to compare apples to apples.

In any case... for every anecdotal case of a window unit not holding up, there dozens of other applications you never hear of because they work just fine for many years trouble free. Rooftop units fail prematurely in some cases as well and many work for years trouble free. One thing I suspect is that there are many more manufactures of Window AC's (and prices) due to larger market and subsequently, more variance in quality.... and RV Air Conditioners are only made by a few (again due to a comparatively limited market)... so quality is probably more on par with less variance. I'd also wager, the RV AC Manufactures are buying key components (compressors, coils, and etc,) from the same suppliers... It is just the way it is.

In any case... this is an age old discussion... folks should just get what they want that fits their needs, comfort level, budget, etc.. It is all good.

[Karebru]

Interesting conversation. I've yet to hit the road... or bumps with my build. One thing I do know... Appliances fail. Seems like you can count on each new one lasting not quite as long as the one it replaces.
I tried to make my $100, built-in window shaker easy to remove and replace. I think that's the best you can do. I'm not even sure it's gonna be big enough.
I thought about using an expensive roof-top unit, but a big part of the fun in DIY is using things in creative and unconventional ways... Build on what other people have done.
Throw away the instruction books. Right?

[bdosborn]

I've got thousands of miles on my window shaker and it's held up fine.


Bruce

[hankaye]

Karebru, Howdy;

Interesting conversation. I've yet to hit the road... or bumps with my build. One thing I do know... Appliances fail. Seems like you can count on each new one lasting not quite as long as the one it replaces.
I tried to make my $100, built-in window shaker easy to remove and replace. I think that's the best you can do. I'm not even sure it's gonna be big enough.
I thought about using an expensive roof-top unit, but a big part of the fun in DIY is using things in creative and unconventional ways... Build on what other people have done.
Throw away the instruction books. Right?

Maybe not so much throwing it away as writing your own.

hank

[Karebru]

Ummm... Yea. That would be the safe way to go.

[McDave]

Window A/C's use reciprocating compressors, and yes they do vibrate and shake and require a fair bit of wattage to start. Rooftop A/C's use scroll type compressors which are typically smoother and easier to start and more efficient. Reciprocating comps. have a piston and crank and connecting rod much like a car, motorcycle or lawn mower. This makes for hard starts because they have to overcome all that friction and load on the first revolution and they get harder to start as they wear. Scroll comps have a fixed scroll and a orbiting scroll. The parts that move are balanced and do not contact the fixed parts. The scroll rotates around a vertical axis which is more smooth and stable than a horizontal axis. There are also considerations made for stress to the copper lines etc. that window A/C's would not normally see.

McDave

Here is an illustration...

[flboy]

Actually, these days, alot (or most) of the window and mini split units are using rotary compressors similar to the scroll in that they are quieter, have a vertical shaft, less moving parts, and have less vibration/noise than reciprocating/piston type.