A.C, main louvers and air outlet Jayflight

homer1959 · 02-22-2019, 08:50 AM

Can you feel a different performance if you keep the main air outlet of the AC closed with all the other outlet open ?

Also guys are you leaving the main outlet always open or always closed or .... my AC is perfoming strangely, main outlet closedperformed flawlessly all day in 90 degrees temps. However during the night when the temp outside was almost even with the one inside the ac start for 1mn and shut down apprx. every 10 mn without really cooling since 1 mn isnt a very long cycle.

This problem happenned a few time , but never with the main outlet open under the ac

Atlee · 02-22-2019, 08:19 PM

The vents on the AC itself are mainly used to rapidly cool the area under the AC unit. If you want cool air distributed to other parts of the trailer, if it has ducted air, the vents on the AC unit itself must be closed.

I almost always have the cooling vents on the AC unit closed. It also seems to be a tad quieter using the cooling ducts to keep the trailer cool.

homer1959 · 02-23-2019, 08:59 AM

Looks like I have found the problem, if its a problem....

I could reproduce it at will, all I have to do is to close the main air outlet under the ac while leaving all the other registry open , then set the A.C in the trailer at temperature outside the trailer and wait ,

It wont take long for the AC to start, to run 1mn , and to shut down. The same cycle start all over again and I waited for 6 of these cycles to confirm that it is not a normal sequence of some sort.

Then to stop this all I had to do is to open the main outlet under the A.C... no more problem to report, ac resume to a perfectly normal operation and cool the trailer pretty well.

So, now I need to find someone to tell me why this is happening but only when the outside temp and inside temps are almost identical. It is some kind of protection ? Any way glad to have resumed to a normal operation during the night...its absolutly annoying to hear the ac startiong and stopping every 10mn or so

o2silverado · 02-23-2019, 09:22 AM

Curious, I had the same issue a couple of times last summer . I just chalked it up to the temp being close to the set point. Since the digital stat has such a small differential . I just bumped the stat up or down a degree and it seemed to fix it .

homer1959 · 02-23-2019, 09:56 AM

Thats what I was thinking last night , initially the therm, was set at 73 it was 78 outside all was good so like you I was thinking about narrow set point differential for the issue the night before

So last night before going to bed I set the therm. to 70, the AC cool down to 70 and not long after ( 2am ) when the temp outside was about 70 the on and off cycle started , my last option was to see if increasing the airflow would help, so i opened fully the main outlet under the ac ... no more cycling after that . Everything returned to normal operation

Some sensor must be looking at the air inside at the evap, and outside at the condensor and decide to cool or not... I need an expert to confirm, I,ve sent an email to Dometic, hopefully Ill get an answer to that.

Quote:

Originally Posted by o2silverado

Curious, I had the same issue a couple of times last summer . I just chalked it up to the temp being close to the set point. Since the digital stat has such a small differential . I just bumped the stat up or down a degree and it seemed to fix it .

homer1959 · 02-23-2019, 11:49 AM

Also despite that it is a new unit i decide to investigate the separation between the cold and return side in the A.C.

Well Dometic can do a much better job, a lot of cold air was moving inside the ac from cold air to return air , the foam seal separating both side is way too thin and a large gap of 1/8 of an inch over 12 inches long was allowing the cold air to be sucked in by the return side. A bit of foam seal, some duct tape and I cant feel any cold air entering the return side anymore

Im sure to see an improvement in the performance of my A.C

o2silverado · 02-23-2019, 11:59 AM

I too addressed the return issue as well as taping all of the supply diffusers. It helped a good deal with keeping the trailer cool . I will be interested in the response you receive from Dometic.

homer1959 · 02-23-2019, 12:03 PM

Taping the diffuser ? You mean removing all the rond louvers or maybe you call that shutters from the ceiling ?

What can be taped ? thanks for you guidance on that

Quote:

Originally Posted by o2silverado

I too addressed the return issue as well as taping all of the supply diffusers. It helped a good deal with keeping the trailer cool . I will be interested in the response you receive from Dometic.

ALJO · 02-23-2019, 12:08 PM

Homer1959: they mean tape it so nothing will escape into the ceiling.

o2silverado · 02-23-2019, 12:10 PM

Yes , if you remove them you will see that they do not seal well with the ductwork. If you tape off the area between the duct and ceiling it prevents air loss into the attic space of the trailer. Some have even trimmed the plastic collar to help with airflow. It tends to stick into the duct quite far.

homer1959 · 02-23-2019, 12:12 PM

Ahhhhhh.... ok and I kind of like the idea of cutting out a bit what stick in the duct ...another job for today :-)

Quote:

Originally Posted by o2silverado

Yes , if you remove them you will see that they do not seal well with the ductwork. If you tape off the area between the duct and ceiling it prevents air loss into the attic space of the trailer. Some have even trimmed the plastic collar to help with airflow. It tends to stick into the duct quite far.

You may also like: