AC not keeping us

[Jumphigh83]

Does anyone have any advice or insight as to why the AC in my class C Jayco can't seem to keep it actually cool in the unit? Granted we are in South Florida in the summer but we had to buy a free standing portable AC and throw the vent out the drivers side window to keep it under eighty degrees inside. Every other camper we've ever had you could freeze yourself out of it if you wanted to! Just wondering if it's the newer units that are affected or because it's a Class C instead of a tag along (what we've always had)? Thanks for any insight.
Betsy

 

[Optimistic Paranoid]

An RV or A/C technician would start by slipping a thermometer like this:

https://www.amazon.com/FJC-1-3-4-Dial-Thermometer/dp/B0002JMEVC/ref=pd_sbs_263_1?_encoding=UTF8&pd_rd_i=B0002JMEVC&pd_rd_r=29Y9SP1W3GV4AKDXPF75&pd_rd_w=rUfNx&pd_rd_wg=3QdFK&psc=1&refRID=29Y9SP1W3GV4AKDXPF75

into the output stream to see what the actual temperature of the air is when it comes out of the unit.

Little hard for us here to offer much advice without more specifics like that.

 

[Back2PA]

As optimistic says, would need more info to know if there?s a problem. The thermometer he suggested is an instant read cooking thermometer. Leave it on the counter for a couple minutes and check the temp. Then stick the end into the duct where the cold air comes out for about 30 seconds. The temp should be around 20 degrees colder. If it is, the AC is working properly. Be sure the intake (?return?) filter is clean to ensure maximum air flow.


How well a single AC will cool depends on many factors, including the size of the AC, the size of your unit, and how well your unit is insulated. Plus if you don?t have good shore power voltage (should be 120) that can greatly affect your AC unit?s ability to cool.

 

[sadixon49]

Welcome to the forum. If you think it's a problem with the Jayco equipment, I just spent a week in central Florida, Disney World, in my 2107 Jayco 26XD, I was easily able to keep the temps in the low 70s throughout the week.

As others have said, check to see if the AC unit is actually cooling, then I would clean all of the filters, and climb on the roof, pull the cover off of the unit, and clean both the condenser and evaporator coils. Many videos on how to do this on You Tube. Just search for RV AC cleaning.

 

[John From Detroit]

List of possible answers is longer than this post. but

I would start on the roof. Remove outer cover and on MOST (Coleman is an exception) the inner cover over the condenser (hot) coils and see if they need cleaning.  Colemans SUCK so you only need to remove the outer cover  (The rest blow, and by that I am referring to the direction of the air flow over the condenser).

After that .. It is getting hotter and hotter so what used to hang meat now melts chocolate.

And then.. If it fails the Thermometer test mentioned above (Output should be 20-30 degrees less than Inlet temp).. You may have to throw $$$$ at it.

 

[Jumphigh83]

Thanks all. I don't have a thermometer but it feels cold coming out of the ceiling... I guess I expected that a less than year old unit wouldn't need serious $$ or a lot of tech savvy. My other campers (tag a longs) you could make like the arctic.. We just had to have a new sending unit or in. Let me tell you about ten days in South Florida with NO AC (hence the free standing unit). I guess I'll have to take it into RV One and see about the warranty. I appreciate the comments and I'll check the roof. It's a Coleman-Mach AC.

 

[xrated]

List of possible answers is longer than this post. but

I would start on the roof. Remove outer cover and on MOST (Coleman is an exception) the inner cover over the condenser (hot) coils and see if they need cleaning.  Colemans SUCK so you only need to remove the outer cover  (The rest blow, and by that I am referring to the direction of the air flow over the condenser).

After that .. It is getting hotter and hotter so what used to hang meat now melts chocolate.

And then.. If it fails the Thermometer test mentioned above (Output should be 20-30 degrees less than Inlet temp).. You may have to throw $$$$ at it.

Not sure where you heard 20-30 degrees, but that's wrong.  An A/C unit that is doing 18-20 degrees differential between inlet and outlet temperatures is operating about as well as it is designed to do.

 

[Rene T]

Do you have  ceiling vent in another part of the roof? You may be able to add another AC if it's prewired. Do you have a 30 Amp or 50 Amp RV.

 

[blw2]

I've understood to use approx 15-20 degrees differential as the "target"
Also, prob a small difference in most cases, but measure the temperature of the air right at the cold air return..... the intake filter...rather than the temp at the counter.  Several reason, but it could be colder there than on your counter.

I'd suggest doing this measurement is the very best first step you can make.  It tells you if the unit is working...if it's not giving you that differential temp, then this points to dirty coils, low freon, electrical problems, etc...
I'd bet odds are really good that it's around 20 degree drop....  If you are, then it points elsewhere.

I'm finding that the unit on mine, Coleman Mach 15, is undersized for the need...it's probably not a very efficient/modern unit either.... all opinions shared by many on the Thor forum I follow for others of the same brand I have.
Anyway, I've found that if you get the RV really cold in the AM before the day heats up, then it might be able to struggle along through most of the afternoon before it heats up too much.  Starting mid day to cool down a hot RV...forget it.

One fairly common problem it seems is the opening from the AC to the roof ducts is sometimes not opened up properly at the factory. 
Some people have reported air leaks in the plenums that can be taped up to help a little bit.
I found just this past weekend that I've had a short circuit all these years...not electrical, but cold air coming form the discharge plenum straight over through a leak to the intake plenum, just recirculating...

another suggestion I've seen is to install another cold air vent right at the AC...
assuming yours has the roof ducting and a similar AC to mine....one half of the cover in the ceiling is filter.  the other half is where the cold air comes out of the unit.  Take that cover down and you'll understand.  Well, some folks are buying one of those round vent louvers, i'm guessing 4 inch diameter or so, like you prob have in your ceiling vents.... and install that right in the middle of that cold air discharge side.... gives a straight path for the unit to dump cold air into the RV.  I haven't done it...yet...but folks report that it helps.

 

[sightseers]

15 degrees difference is about all you can hope for..

When it was 118 outside last week,  inside my dark air-conditioned living room it was 101,  and it felt like heaven.

 

[John From Detroit]

20-30 is by actual measurement.
20 is considred excelent by the way but I've seen 30.

You do not have a thermomemter.. Get ye to a hardware store, Supermarket, Camping store.

I common digital Meat/cooking thermometer works very well and... Also tells you when the Chicken is safe to eat..

 

[Frank B]

blw2:

another suggestion I've seen is to install another cold air vent right at the AC...assuming yours has the roof ducting and a similar AC to mine....one half of the cover in the ceiling is filter.  the other half is where the cold air comes out of the unit.  Take that cover down and you'll understand.  Well, some folks are buying one of those round vent louvers, i'm guessing 4 inch diameter or so, like you prob have in your ceiling vents.... and install that right in the middle of that cold air discharge side.... gives a straight path for the unit to dump cold air into the RV.  I haven't done it...yet...but folks report that it helps.

Thanks for that. I had my Coleman 1350 unit apart for another reason a few days ago, and I wondered about that very issue.  Good to know! 


Being Canadians, and snowbirds, we rarely use our air conditioner at all. However, I am glad to have that information for 'future considerations'.


Frank.

 

[sightseers]

I'm sure the air temp coming out of the unit is 20 to 30 degrees cooler,

but with most rigs, the overall inside RV temp will end up being about 15 degrees colder than the outside temp. 

When it's been over 105 for several days in a row ...all we can get is 11 degrees difference.

 

[Utclmjmpr]

  You also have to start the A/C early in the day,, don't try to "catch up" and wait till it's warm to start it.>>>Dan

 

[sightseers]

  You also have to start the A/C early in the day,, don't try to "catch up" and wait till it's worm to start it.>>>Dan

on those days as soon as the sun comes up both A/C's go on high.  it's often in the 90's at night.

 

[Hammster]

I admit I haven't read all the answers, so this may have already been asked and answered.
Have you checked the inlet/outlet baffle in the air con? You can access it by removing the AC cover inside the rig. It's just a 1" or less thick panel with some foam on the edges that should be completely vertical and between the supply side and return side of the cavity there. Make sure it is not tilted over allowing air to short cycle. Also, if your AC system is ducted make sure you have the vents on the AC panel closed off so the ducts can better distribute the AC.

 

[xrated]

20-30 is by actual measurement.
20 is considred excelent by the way but I've seen 30.

You do not have a thermomemter.. Get ye to a hardware store, Supermarket, Camping store.

I common digital Meat/cooking thermometer works very well and... Also tells you when the Chicken is safe to eat..

I've seen 30 degrees differential a couple of time also......on units that were grossly oversized for the job.....which I seriously doubt you will EVER find in an RV.  Suffice to say, that in almost all applications....18-20 is the normal for an A/C unit that is operating properly.

 

[Patnsuzanne]

One possible solution, or at least some help, would be to put some sort of insulation in the windows and especially the windshield. We don?t have a coach, but have found the blackout shades we made for our trailer also do a pretty fair job of keeping it cooler. There was another thread here just a couple of days ago from a member that used foil backed insulated sheets in the windows with pretty dramatic results.  The only drawback is that you can?t see out of the windows, but we generally only cover the windows exposed to the sunlight, and then when evening rolls around, take the shades back off.