New Air conditioning system for 2020 - Elwell Air-8

Cbusguy

So the issues seems to be with air temps above 90.  

the air temps here so far this summer havent exceed 90,  so I will have to wait and see if ours acts up with air temps that high.   I will post when I get a chance to test it.

pathfnd1

Please do post. Thank you.

Mariner459

Folks, 
We had similar issues day 1 of getting new 2020 400. While in 69 degrees sunny weather, AC was running an hour or two, then it stopped cooling but fan was fine. We looked at the intake and exhaust vents outside under the rear area while unit was on.  We saw that after the hot air from the condenser blew over the cold air intake, the louver cover got warm and collapsed with the intake suction impeding airflow and AC's ability to remove heat. Then the AC stopped cooling altogether.  Fan still ran. We turned everything off and returned to the dealer the next morning. We shut it off before any error occurred. We also noted the next morning that the louver cover had cooled and retracted to original shape but paint was flecking off from prior distortion. We determined the intake and exhaust are simply too close together and recycling hot air.  We worked with our dealer, and they built a mod diverter to direct the hot air to the sides and away from the cold air intake to stop hot temps going in.  It now works to capacity.  We asked the dealer to report this mod to Nucamp. The error may indicate the compressor has been overheated from the hot air as well as the physical restriction of the collapse.  Please note that stargazing window is also a huge heat load in sun. We now insert a sheet of reflectix with about a 2 inch air gap mid morning and keep it there till sun moves  to other side...this helps.  We also hope the EER rating in manual is a typo....surely this is not a 2.5 EER!

See yall at the Pacific NW Jam in Sept!  

pathfnd1

Mariner459

Thanks SO much for posting this. Which dealer built that cool mod diverter for you?

Mariner459

Chris and Phil at Apache Camping Center Service Dept, Poulsbo, WA helped us.  Frank (Mr. Mariner459) worked in heating/AC years ago but Chris built this diverter. We love those guys.  We have them come to the Pacific NW Jamboree every year.

mreric

i think more Rv should move to this design and away from the roof mounted version, i could look at many more R/Vs  as most of the time is the A/C height that prevents me from storing the R/v in my garage. 

pathfnd1

Thanks. In case mine needs similar work, I'll know who did it. 

pathfnd1

Mariner459

If you find out, would you tell us here if the EER rating in the manual is correct?

Cbusguy

Well SEER is an AC rating.    So hopefully it isn't 2 SEER.   

But the manual is so poorly done it is hard to tell.  The Elwell is completely unresponsive as I have attempted to contact them via email and phone.   

I hope that this exterior ducting mod is the fix.

Verna

I have forwarded this problem and fix to the nüCamp factory.  Thanks for the photo, @Mariner459.

Verna — T@B Admin

pathfnd1

Verna

Do you know if either the Nucamp factory or any Nucamp dealers will now automatically perform this mod on their 2020 400s before they're sold?

Or, is the question of whether the mod needs to be done on anyone's particular TAB 400 one whose answer is likely to be the responsibility by each buyer to determine, depending on the performance of the Elwell of his or her TAB 400?

Or, if we don't know the above, who has typically determined the need for  mods for key systems like a/c in the past, the buyer when their a/c fails, or the nucamp factory or dealer as a prophylactic mod?

Thank you. 

Mariner459

@cbusguy....Mr. Mariner459 explained the difference between EER and SEER when I mentioned it again.  A full engineering explanation :-) Either way, let's hope a 2 something is a typo. He also spoke with a gentleman at the number in the manual who said he was Mr. Elwell, and they discussed the hot air recirculation possibility but we did not hear back from him. Also, Chris removed about a foot of excess hose length that was running from the unit to one of the vents...it was crammed in a figure 8 and just wasn't necessary.

Verna

pathfnd1 said:

Verna

Do you know if either the Nucamp factory or any Nucamp dealers will now automatically perform this mod on their 2020 400s before they're sold?

Or, is the question of whether the mod needs to be done on anyone's particular TAB 400 one whose answer is likely to be the responsibility by each buyer to determine, depending on the performance of the Elwell of his or her TAB 400?

Or, if we don't know the above, who has typically determined the need for  mods for key systems like a/c in the past, the buyer when their a/c fails, or the nucamp factory or dealer as a prophylactic mod?

Thank you. 

The email was just sent this am. The factory cannot do things to an entire line of T@B’s in a minute nor a day. Please give them time to get back to me and I will have answers. 

pathfnd1

Excellent, and thank you!

Cbusguy

@Mariner459 I don't see any explanation in  your post for the difference between eer or seer.   "@cbusguy....Mr. Mariner459 explained the difference between EER and SEER when I mentioned it again."

I was thinking it was a typo,   Instead of 2.5 EER but 2 SEER

google to the rescue,  EER is used in small window sized AC units.  where SEER is used in home or commercial stuff.

You had more luck talking to the Elwell folks than I did.   I just asked for manuals.  Guessing they don't exist yet

1968Healey

I don't claim to be a SEER vs EER expert, but I do know my home heatpump has a SEER rating closer to 16, so 2.5 isn't great.

This link seems to be a decent overview of SEER vs EER, but basically it can be summed up as "Where EER is calculated using a steady outside temperature of 95°F, SEER is calculated using a range of outside temperatures ranging from 65°F to 104°F."

We took delivery of our 2020 Tab 400 this week and ran the AC for ~1 hour on Wednesday when it was almost 95 deg.  We also bought from an Apache dealer in WA, so hopefully if we need a fix, we can just go to Poulsbo to have it done.

Other than the 'doesn't work in the heat' issue, I'm otherwise pretty happy with the AC unit changes.  It fits nicely under the bed and service access is pretty good.  I can see why it's much lighter, the whole case is just styrofoam. We were easily cooling the whole trailer with a single 15amp outlet.  I also think the bin under the front dinette area is a much better use of space.

Somewhat related, the batteries on the 2020 Tab 400 have also moved, they are now directly behind the AC in the center of the bed.  4 screws to take the center bed cover off and you have 100% access to the batteries.  It's a much easier setup than the previous plastic cover that spanned two bays.

Mariner459

My takeaway was SEER is a seasonal snapshot of data rating essentially.  The HVAC pros are more reliant on EER data apparently. :-)

BigShowSkipper

Thank you Mariner 459. Your assessment was spot on. The hot exhaust air blows directly over the cool air intake. The very hot exhaust get drawn up into the intake as you describe. I removed the exhaust vent and re-oriented to direct the exhaust towards the front of the trailer which is away from the intake towards the rear. . The AC has been running constantly for 5 hours now and is keeping the trailer cool enough to get through 103 degrees outside. This is great new for those of us in hot areas. 

I will I’ll work with dealer to fabricate an even better long term solution when I get some warranty work done in a few weeks  

these were both taken after the mod  you can see best in the second picture how refacing the vent helps  

RollingBnB

Any chance you will injest rain water on the forward facing vent when driving in a storm?

BigShowSkipper

Certainly possible but this is a just a temporary fix until I get in for other warranty stuff. No plans for trailer to be moving in rain before I get it in. 

More of a test to see if redirecting away from intake would allow the AC to function in our aweful heat. 

Mariner459

@BigShowSkipper we are happy that we may have been able to help yall and Nucamp with an idea.  When Mr. Mariner459 first inspected under there when the AC started blowing only warm air, he saw the louvered intake cover all scrunched up into the airway opening. We didn't realize it was painted plastic.  We thought something had hit it just right and crushed it up into the opening and thought that blockage was the only problem. He turned the unit off immediately.  Over dinner he was describing it to me, trying to imagine how and when that could have happened in the about 5 mile drive on excellent road from the dealer brand new....and I suggested we send the dealer a photo.  We were going to need a new cover at a minimum. I asked whether he had pictures yet? No, but tomorrow morning he would. We talked about where to buy a new louvered cover. The next morning he went out to take pictures and did a doubletake. The cover was not crushed. Some thinking and jaw rubbing ensued. We determined it must have relaxed back in place when it got relief from the nearby hot exhaust...scrunching and unscrunching when the air was stopped left the clue that the paint was flecking off. What????? Must have been that heat and suction was relieved by turning it off to cool.(He truly is an ace troubleshooter I might add.) We just headed back to the dealer and started working with them on the issue and mod.  And that is "the rest of the story."

TNOutback

Even with the louvers turned around for the exhaust, it would seem that you are still dumping hot air underneath in the same area as the intake, with the floor of the camper “holding” it in the area - unless there is a good breeze to take it away.  Seems to me it almost needs an enclosed channel, sufficient for the volume of air required, to carry it closer to the edge of the camper close to where the service door is for the water valves.  A more enclosed approach would also help keep rain and road dust out of the intake.

RCB

The Truma unit installation instructions recommend that it be installed so a frame member of the trailer lies between the inlet and outlet ducts. This would provide some separation of the grilles with the frame member acting as a baffle. The solution showing a sideways duct extension should work. However, I would increase the separation between the inlet and outlet to minimize short circuiting of air flow. Short circuiting of supply and return air is a common problem in duct layouts in buildings and basically this issue is no different. 

Sharon_is_SAM

@RCB, you would recommend extending the length of the exhaust diverter or would you add another diverter to the cool air intake?

RCB

Probably either way will work. The objective is to separate the air flow as much as possible. The installation drawings show the air outlet and inlet on the bottom of the unit. They are of different shapes and dimensions. One is more forward than the other assuming the unit is installed crossways in the RV. Look at the installation instructions on Truma.com for the 1800 watt cooling unit. This is probably an issue NuCamp should address.
ps how does one add the blue salutation at the beginning of the message ?

Sharon_is_SAM

@RCB, type the “@“ sign immediately followed by the first few letters of the desired username.  Vanilla then provides a pop up list of names that begin with the same first few letters.  Select the username from the pop up list.

RCB

@Sam  Thanks

b407driver

RCB said:

@Sam  Thanks

What you typed above would flag the user named 'Sam', not the user 'Sharon_is_SAM', just for the record...

Mariner459

@RCB as soon as you type the @ sign and the first letter or letters of the forum person you wish to write a heads up for...note your cursor tip and you will see a drop down list of known forum members with those letters. When I typed "@rc" you appeared in a selection list for my quick click :-)

Arizonayeti

My warranty adviser received an email from nuCamp today stating they have discovered "an issue" with the Air8 and will have a solution in process by the end of the week.  I'm assuming this relates to the airflow restriction caused by the underside vents, but we will see.