Brand new fifth wheel no A/C

[Farmer97]

We purchased a brand new 357mdok and set up camp over the weekend and the a/c could not keep the coach cool. It would blow coolish air but during the day it would be the same temperature inside as it was outside, overnight it would cool down to the desired temperature but rise again by noon. Am I foolish to believe that the air should at least keep the coach comfortable?

[Big1]

Welcome from WA. Now do you have two a/c? Normally these a/c in these fiver will only cool it down to 20 degree down from what's outside.

[Big1]

There are a few things that you can do to make it a little better those, do a search and other will chime in.

[Farmer97]

Cooling to 20 degrees less than outside would have been great but it would not even do 5. There was only one unit, I have actually added another in the front to help. But the dealer is telling me there is no problem and apparently doesn’t believe me it doesn’t keep up.

[Lake Huron]

They are feeding you a line of BS.
A dealer installed a 2nd unit on my buddy's 29.5 and the only difference it made was in the front bedroom. While we were camping we took off the interior covers and found those bozo's didnt even cut it into the main duct work. We did a "camping repair" and made it WAY better. Once he got home he got neck deep into it and made things work much better.
I did the same thing a few weeks back and made HUGE improvements.
Your issue sounds like some poor workmanship when things were installed like mine was, but yours is on a greater scale. 5* difference is totally unacceptable. Especially if you have 2 units.

[TxLoser]

What is the temp of air coming from the vents? What’s the outside temp, and do you have any shade? Lastly, what settings are you using. Cool Hi/Cool Low, etc? I routinely use my meat thermometer to check my duct temps when I doubt the system. Also, on my unit the hi and low settings were wired backwards. Didn’t impact things too much, but something to consider.

My unit is a hair smaller than yours and it takes some time and both AC units to cool it off on a hot day without shade. Once cool, generally one can keep it cool.

[Grumpy]

Originally Posted by Big1

Welcome from WA. Now do you have two a/c? Normally these a/c in these fiver will only cool it down to 20 degree down from what's outside.

And that is somewhat of a misnomer. There should be a 15-20 degree temp drop across the coil.. If the air temp is 85 the temp of the air coming out of the vent closest to the a/c should be 65-70 and that doesn't always give you a 20 degree inside to outside difference.

Since it is the ducted system check all the vents to be sure they are sealed properly and the cool air is not going into the roof. Remove each one and make sure the aluminum tape is in place. You definitely need the 2nd a/c.

[Big1]

Originally Posted by Lake Huron

They are feeding you a line of BS.
A dealer installed a 2nd unit on my buddy's 29.5 and the only difference it made was in the front bedroom. While we were camping we took off the interior covers and found those bozo's didnt even cut it into the main duct work. We did a "camping repair" and made it WAY better. Once he got home he got neck deep into it and made things work much better.
I did the same thing a few weeks back and made HUGE improvements.
Your issue sounds like some poor workmanship when things were installed like mine was, but yours is on a greater scale. 5* difference is totally unacceptable. Especially if you have 2 units.

^^Believe this^^ after have had one a/c and have two now I would never buy a fiver with only one a/c on where we go anyway.

[Big1]

I did do this to all of my vents even in my bedroom I took that big a/c cover off and found that the divider was over in the incoming hot air side but I don't have any pics of that.

When I was taken all of the vent cover out I found that they had put some scrape foam in the ceiling so of course I clean that out.