Adding a portable air conditioner to 30A coach

[jbrosecity]

Originally Posted by TitanMike

Just remember, while the roof is white it also has twice the thickness of insulation than walls.
Some of the difference is due to the higher R value of the roof.
Other than that the basic's are correct. Dark sucks up heat, light tends to reflect.

Exactly - but FBP looks so much classier than all white or even the cream colored gelcoat with decals that many are using these days. Ah the price of vanity! One other factoid I learned... when you have a ducted roof air unit like ours, it is so much quieter than the less expensive "push it all out the A/C grate". HOWEVER, and I never thought of this, the air inside the ducts is being heated by the sun on the roof. One comment in this thread was about the efficiency of the exhaust hose on our portable A/C giving off heat (an issue easily dealt with by making a quick quilted or insulated hose jacket), but there is nothing to be done about the ducts in the ceiling, which lose a lot more efficiency, especially as they make their way to the rear of the coach.

Maybe the ducts in the ceiling of a million dollar Newell or Foretravel are insulated, I don't know, but definitely the ducts in the Forester's ceiling are NOT. I have a thermometer at home which accurately measures the temperature at the air output of an A/C. A/C service techs use these all the time. I will bring mine back from home in August and compare temps at the grate front and rear and from the portable unit and will post those results.

[Big bird]

Your going to put the portable in a window? OK, I assume you are not going to drive the unit with an AC hanging out. As for 30 versus 50 a. If you use independent power source no problem. If you put 50 a in a 30 a system do not go to sleep.

[CaptnJohn]

Well, I learned something today. We have a 2019 41’ 5er with 2 15 AC units, both ducted. I’m glad I did not order the 3rd ac unit it is wired for. Temps have been 94 - 99 index to 111 and no problem keeping inside at 72-73. A tree keeps us from putting out either of 2 awnings but we keep the double shades down.

[CurtPutnam]

I have a portable unit. Tried cooling my garage with it. Discovered that the exhaust is hot enough to act as a radiator unless the tube is incredibly well insulated. The shorter and more direct the exhaust run, the better.

[B. R. Mullen]

Don't plug unit into trailer. You have to vent out a window so get some thick foam cut to fit window you want to vent out of cut hole for vent to go through get big enough wire extension cord run it through window foam will hold it plug it into electrical post and plug in a/c. We have two units that way works great

[BrianSmith]

Portable AC units work great if you also duct the intake air that cools the condensing coil.
Their normal configuration with only a ducted exhaust of the heated air utilizing room air on the intake side is nuts !

[A32Deuce]

Need the type with 2 hoses. One in and one out. Almost double the price.

[jbrosecity]

Originally Posted by Big bird

Your going to put the portable in a window? OK, I assume you are not going to drive the unit with an AC hanging out. As for 30 versus 50 a. If you use independent power source no problem. If you put 50 a in a 30 a system do not go to sleep.

Only the exhaust is vented thru a custom made insert in one of the little sliders in the cabover bunk area. We are going to use a louvered dryer tupe vent over the outlet with a screen. But when we drive we will mostly move the AC to the closet and secure it, and remove the vent insert from the window

As for connecting to a 50A outlet for power to an 11A A/C, this is a common misconception that there is some problem with this. I have seen extensive discussions on other forum threads before, and ALL the concerns are unfounded. Trust me, I have run this by Electrical engineers and professional electricians and HVAC guy to be sure. As long as you are only using part of the 50A and have have adequate gauge electrical cables in place, this is perfectly ok. 100%. The only concern is if something in the A/C should short on a 50A circuit and the short was less than would trip the 50A breaker, so for that you need a 20A breaker inline, and this A/C has a breaker GFCI right on the power cord, so I have been assured that this is completely safe.

[jbrosecity]

Originally Posted by A32Deuce

Need the type with 2 hoses. One in and one out. Almost double the price.

not at all... we are doing exactly that... and the coach is now so cold we have to turn up the temp on thermostat. The amount of heat generated from the exhaust tube is maybe 1/10th the cooling that comes out the vents and with a quilted insulated sleeve over the exhaust tube the heat is negligible. There is absolutely ZERO need for a double ducted unit. Our situation is proof of that. This issue ad already been discussed in an earlier post. This new frigidaire is awesome... so quiet you cannot even hear it in low fan mode and quieter than the roof air even in high fan speed mode. It directs cold air up to the ceiling which is perfect. I already posted the measure interior wall temps measured with my raytek. We have been using the unit a month now with this installation and are 100% pleased with the outcome. It is working out even better than expected

[A32Deuce]

I have 2 of them and they both suck inside air out. That means the air has to come from some where!