Air conditioning problem

[rancherwillie]

We have a 2012 Winnebago aspect,,model 30j. The Coleman 13.5 roof air unit does a terrible job when it approaches 90-100 degrees outside. We are lucky to have 85 degrees inside. I had the unit tested and it lowered outside air by 12 degrees. The tech guy said that's all they were designed to do. He also said the ac housing and black exterior stripping were a problem. Ant thoughts on this will be appreciated. Would a white, 15000 unit help? Thanks. Willie

[KAttkisson]

Getting back to the under-performing AC. bought a used class c and was not satisfied with the ac performance. It was a ducted system with the chill grill. Lived with it for as while thinking it was what it was. I ended up having to change A-C unit on roof to get lower roof clearance for in building storage that became available.When I removed the chill-grill I found that the mid-section seals had been ripped by the PO allowing air to short circuit. I say seals but a large part of the setup was metallic duct tape. Quick to check and boy did it make a difference.

[TyroneandGladys]

Been discussed before Click
I use one in a vacation home and they are not as efficient as a window unit but they do cool. Keep in mind that your electrical capacity for your RV will be close to max with two AC running. I run a heavy extension cord from the 20 amp receptacle on the pedestal into our RV to use a space heater. I cut a piece of foam pipe insulation the length of the side cab window fit it on the glass lay the cord across it and roll the window back up to just snug and it gives a good seal.

[Tramp844]

Does anyone use a portable freestanding ac ? does it help ? are they worth the $300 price ? my class c has 1 ac unit, not sure of btu, can i add a second unit without modding the roof ? Like maybe where the overhead vent is in the back bedroom ?

[ol__yeller]

Our 2008 Aspect 26A originally came from Arizona. I am the 3rd owner. The OP outfitted the RV with a slide cover, dual pane dark tinted windows and awnings. The mistakes were (I surmise) a dark full body paint, nothing isolating the cab, and a 13.5 AC unit. In the 2 years since I have had it, I have only had to run the AC to exercise the genny but then again I live in the Great Northwet.

[Prowlers80]

I have a 32 ft Montana that the air conditioner is making a huge vibration in it that shakes the entire camper. I have checked the bolts and fans with no luck.. I took the top cover off and ran it and it seems like the compressor fan is the culprit. Is there anyway to replace this or repair it?

[Maestro402]

I am a newbie as well and learning about my AC and how to have my RV setup for optimal conditions on hot days.

This weekend I had some extra reflectix so i made interior window covers for the windows in the rear of the coach. I used velcro strips so i can remove them when we want. Not sure how much this will help but it surely can't hurt. 😉

We are going to Bristol next week so i'll know more about how much it helps. 🙂

[Old_Crows]

Willie, Not previously mentioned:

It is important to have all ducts opened fully to have unrestricted air flow off the unit to all areas of the RV. If the unit has the "Chill-Grill" option you want it CLOSED so the cold air gets to all areas.

Fan set to AUTO not ON.

The Mach 8's thermostat should have a two speed fan. Set to LOW. You want the circulation fan on LOW so the air spends a "wee bit" more time over the expansion coil so it has more time to cool.

Set your thermostat at 70-75ish. Setting lower does not make more cold..... Ultimately, in high ambient humidity you want the compressor cycling ON & OFF. If it runs constantly there is a risk of the expansion coil freezing to a block of ice and all you get is clammy, tepid air.

If you suspect a frozen unit, (cool, clammy, reduced air flow) just ease the thermostat up until the compressor turns off. You MAY turn fan to ON to melt ice block but it will put the humidity back in the RV. Left alone, it will clear pretty quickly and just drain off the roof.

I hope this helps...

[SkiingSixPack]

TyroneandGladys wrote:

2oldman wrote:

SkiingSixPack wrote:
Like others have said, the 20 degree drop is the inside air vs. the air coming out of the AC vent.

I don't agree with this.

My air gets down to the 50s, no matter what the intake air temp, but the best the temperature is going to get inside is about 20 degrees below ambient. I think that's the meaning of the 20 degrees.

Somehow I don't think 80 degree ducted air is going to do much cooling in a 100F trailer.

Am I understanding what you said ?

First worked with AC's in the early 70's and this one thing has not changed take a thermometer and measure the room temperature then measure the temperature coming out of the AC and if it is at least 20 degrees cooler then the AC is working correctly. Example the room is 100 and the air coming out of the AC is 80 it is working properly. No it does not mean that it will only cool to 80.
If you do not have to much heat gain and you are not trying to cool to large of an area for the size AC the 80 degree air will cool the 100 degree RV to 95 now you have 75 degree air coming out of the AC.
Again provided that the area that is being cooled is not to large and the heat gain is not to high the 75 degree air will cool off the 95 degree air and this process will continue to the max cooling of an AC which is approximately 65 degree air if you get colder great but do not count on it.
And as I stated one of the keys is not to let it get to 100 before you start trying to cool it off.
If you start early when it is 80 inside and the temperature climbs to 100 with the AC running and you have the 20 degree drop the AC is functioning properly then you are trying to cool to large of an area and or you have to much heat gain.

^^^ this.
What Tyrone said!

[2oldman]

TyroneandGladys wrote:
.. the 75 degree air will cool off the 95 degree air and this process will continue to the max cooling of an AC which is approximately 65 degree air if you get colder great but do not count on it.

Today I let my rig heat up to 88. I turned the air on, and within 5 minutes the vents were around 55.

11 minutes later the coach is at 87 and the vents are 46.

I'd say that's pretty good.

[rancherwillie]

Thank you all again for the great tips and data. I plan to get another shop to test the air system before going forward. Willie

[rockhillmanor]

The Coleman 13.5 roof air unit does a terrible job when it approaches 90-100 degrees outside. We are lucky to have 85 degrees inside...

You are not the lone ranger. It is NOT your air conditioner.
It's the nature of the beast. An RV is nothing more than big box sitting out in the sun.

"YOU" have to make adjustments when RV'ing in real hot weather states.

1. Cover the windshield - Camco makes a good cover
2. Cover the side windows in the cab - they make ones that pop open to fit
3. Cover ALL your roof top vents - RV pillow inserts
4. Cover the windows in the coach area that are facing the sun. Slip van windshield sunshades under the day/night shades.
5. Cover window on entry door - camco makes one to fit door window.
6. If sun is on awning side drop awning to the lowest position to block sun.

7. If at all possible find parking where there are trees for shade and park 'facing' East or West. That way the sun is not hitting the full entire side of your RV in the morning and afternoon where all the windows are.

My first time in Florida I too freaked out how hot it was inside the RV with the air on. Then I learned about what you need to do to be proactive to help assist the ac and be comfortable inside.

The pillow vents alone dropped the temp inside the MH drastically. I have 3 roof vents and was amazed how much heat comes thru those and how much of your ac goes out them. The lids on those are not sealed. Covering the coach windshield and the rest made a BIG BIG difference.

And if you are in an area where the temps reach 100? You need to get a cover over the cab area too. Take a blanket whatever and cover that opening from cab to coach. I just slip the cover under the mattress on the cab over to hold it in place. THAT makes a huge dif also. One time the temps outside where so hot I also had to cover the skylight in the bathroom so much heat was coming in from there. Used removable limo tint on that!

[We_Cant_Wait]

dtappy3353; In referring to the dog house I'm talking about the tin structure that encloses the cooling coils.

[TyroneandGladys]

2oldman wrote:

SkiingSixPack wrote:
Like others have said, the 20 degree drop is the inside air vs. the air coming out of the AC vent.

I don't agree with this.

My air gets down to the 50s, no matter what the intake air temp, but the best the temperature is going to get inside is about 20 degrees below ambient. I think that's the meaning of the 20 degrees.

Somehow I don't think 80 degree ducted air is going to do much cooling in a 100F trailer.

Am I understanding what you said ?

First worked with AC's in the early 70's and this one thing has not changed take a thermometer and measure the room temperature then measure the temperature coming out of the AC and if it is at least 20 degrees cooler then the AC is working correctly. Example the room is 100 and the air coming out of the AC is 80 it is working properly. No it does not mean that it will only cool to 80.
If you do not have to much heat gain and you are not trying to cool to large of an area for the size AC the 80 degree air will cool the 100 degree RV to 95 now you have 75 degree air coming out of the AC.
Again provided that the area that is being cooled is not to large and the heat gain is not to high the 75 degree air will cool off the 95 degree air and this process will continue to the max cooling of an AC which is approximately 65 degree air if you get colder great but do not count on it.
And as I stated one of the keys is not to let it get to 100 before you start trying to cool it off.
If you start early when it is 80 inside and the temperature climbs to 100 with the AC running and you have the 20 degree drop the AC is functioning properly then you are trying to cool to large of an area and or you have to much heat gain.

[Bordercollie]

Try to camp under trees with awning out to reflect some of the heat and shad the side of the rig. Put reflective material in the windows and windshield to reduce heat coming in. Put a blanket or other barrier to contain heat in the cab area. Run the roof AC before sun can heat up the exterior of the RV.

We avoid camping or RV'ing in 90+ degree weather. Don't like being cooped up in an RV with barely adequate AC. No place like home "with all the comforts of home."