Very unhappy with new AC system!

[DarMar]

Originally Posted by fre1fred2

Thanks!. So my return vents are rectangle and return duct is rectangle as well, the return duct is about 8" x 1". Do you mean to open that 1" duct with the 2" PVC?

We used the 1.5 inch pipe cut in 8 inch length and centred it in the rectangular vent pointing to the centre of the camper and pushed it up into the duct until it was flush with the inside edge of the duct.

With the 1.5 inch pipe we found more than enough friction to hold the pipe in place.

[vipermanden]

Yes, you want to expand that narrow opening, which sometimes is not even 1". Some guys have even used PVC couplers and shoved pipe in the opening as far as they could push. I just did the approx. 4" long pieces, and it seemed to do the trick. I also don't run the roof fan, when it is a hot day, so the hot air can settle at the top inside the RV rather than being blown back down. I did see a 22 degree difference on my last trip when it was 99 outside, and 77 inside. They say they that about 20 degrees is the best you will get, since the walls and roof on the RV, are not like our homes.

[fre1fred2]

Thanks guys. That is a tiny opening... I wasn't sure that's what you meant after seeing how small it was...

[vipermanden]

Fred,

I think the pics of the vents I bought were in another topic, so here are the pics of the stock sleeve and vent vs. the after market ones I bought for $7 each. Like I said, you can chop the walls of the sleeve down so it does not restrict air flow, if you don't want to buy 9-10 vents for $7 each.

[Rondo]

There have been a few posts here on the Forum about the vents and how they are to high in the duct and restrict the airflow. Quite a few have cut their vents down as Vipermanden did, I presume. You can also purchase the vents that go into an SOB that can be closed and they seem to work also.

[richfaa]

Last summer we were in Shawnee, Ok it was 107 degrees high humidity and with both A/C running full blast we managed to not expire from the heat and humidity. We are now in Maine average temp here is 80 or so with 60% humidity both A.C running will freeze us out. What do you make of that//////

[Rondo]

I'd say "Bring some of that coolness out here to Nebraska, Rich!" Temps in upper 90's to 100's, humidity at around 70% and heat index skyrocketing. Enjoy those temps Rich and give Helen a hug from us!

[DQDick]

We're up to 110 here in Kansas today (actual temp not heat index) in full sun. The rig is 22 degrees cooler than outside, but that's still pretty hot.

[Good Life]

102 here in Branson after some coonass enginuanty ours has held steady at mid 70's

[CaptnJohn]

My rig goes to the dealer tomorrow for slide toppers and a warranty list. When it returns I plan on blocking the furnace vents in the stairs 1st. Then I'll look for damper floor registers (brown) and see if there is any improvement. A damper ceiling AC vent in needed in the bathroom as you can freeze in there. I'm thinking thesehttp://www.pplmotorhomes.com/parts/cfp/vents/ceiling-ac-vents/61452.htm?utm_source=google&utm_medium=partsshoppi ng&utm_campaign=partsfeed&jt=1&jap=1o4&js=1&jsid=3 6859&jcpid=8a8ae4cd48005458014820e2e0170ec4&jkId=g cp:se_36859p_49866614678:ag_15211804824:cp_19425 3624:n_g:d_c:cr_52737673584&gclid=CNy-8qH_vs0CFQkwaQodgTQApw as they will be closed in the winter. Any comments for plan changes?

[bshgto]

A little distressing,I just read this post from start to finish I cant believe DW and I are looking at buying a new 3791 RD and trading in the High Country. what will I end up with? This company really sucks doesn`t it.

[Rondo]

You have to remember for every bad post that goes on the Forum here there are, I would guess, over a thousand and more posts that never make it here because the owners are quite satisfied with their units. This is the RV industry and there isn't one brand or model that someone has not had a problem with and those are the ones we hear about not the ones that don't have the problems.

[vipermanden]

bshgto,

Do you own a GTO :-) Anyway, knowing what I know now, the A/C is either installed great or it is not. So, if you have a 5th wheel picked out, show up on a hot day at the dealer, and make them crank it up from a hot start. In other words don't let them know you are coming, and make them turn it on in the middle of the day, and see if it does the trick. Don't forget to bring a temp gauge with you, so you can see the diff between outside and inside temps. Some people say their units work great, and freeze them, others have to do mods like me to get it right.

[CaptnJohn]

Originally Posted by bshgto

A little distressing,I just read this post from start to finish I cant believe DW and I are looking at buying a new 3791 RD and trading in the High Country. what will I end up with? This company really sucks doesn`t it.

When I bought a new 2016 Cougar I had 1 minor warranty item. The new 2017 High Country is in the shop now for slide toppers and a couple items, one I'm not sure of and waiting to hear. Still nothing that cannot be fixed.

We did not need another 5er and were happy with the Cougar. I researched them all. We never hear from the thousands of happy buyers, only the small percentage with a problem. To me it was worth the chance and so far I'm glad I did. Just another part of the adventure.

[bshgto]

I`m not saying I don`t like my camper I do, front cap and a landing gear motor is the only issues I have had in 3 years with this unit, added 3 vents to the a/c and a dehumidifier to the unit and it`s better. I`m just saying a 3791RD is going to come with what issues? I have none now do I want to role the dice? I`ll just wait till Hershey in a few weeks and see what`s up.

[TheKothes]

I purchased a new Montana 3811 in March of 2017. I had it back to the dealer for the AC after we took it out the first time here in Texas. It gets hot here as you might guess and so far we have not been real happy with the AC. We just went to Arlington for a couple days and the AC on High and set to 74 in both zones could not keep up. Outside it was 95 or so and it warmed up to 89 in the RV. It was a little better in the bedroom but it too rose to the low 80's. My 2002 Forest River 28 with one AC unit did much better than this. I am going to make sure both units are 15k and not 13.5k first and check the ductwork again. My front unit is a low profile unit. Does anyone know if this reduces the cooling potential? From reading here I should get at least 15 degrees of cool down. It gets down below 70 at night but the sun just takes all of the cool air away. Plus we have all of the shades pulled and silver insulation on a couple of the windows.

[Good Life]

Originally Posted by TheKothes

I purchased a new Montana 3811 in March of 2017. I had it back to the dealer for the AC after we took it out the first time here in Texas. It gets hot here as you might guess and so far we have not been real happy with the AC. We just went to Arlington for a couple days and the AC on High and set to 74 in both zones could not keep up. Outside it was 95 or so and it warmed up to 89 in the RV. It was a little better in the bedroom but it too rose to the low 80's. My 2002 Forest River 28 with one AC unit did much better than this. I am going to make sure both units are 15k and not 13.5k first and check the ductwork again. My front unit is a low profile unit. Does anyone know if this reduces the cooling potential? From reading here I should get at least 15 degrees of cool down. It gets down below 70 at night but the sun just takes all of the cool air away. Plus we have all of the shades pulled and silver insulation on a couple of the windows.

This is part of whit I did to mine!

We brought our 3721 home last week, along the week long trip we made a mini vacation out of it. I noticed the A/C s struggling, return air grills would not hold a paper towel up!
Off to Home Depot!
I started working on it by removing the grills only to find the rough cut outs in the ceiling and duct was in some places 1" away from the inside of the grill ring, this was on all four!
I took a marker and a pair of tin snips and began to operate on the openings once satisfied I felt up in the ducts and they were almost mashed closed!Also in all 4 ducts low side it was full of sawdust! Vacuumed all out!
Off to Home Depot! Trip 2
Found some 12" X 1-1/2" and 6" pvc tailpiece , bought 4-12", 8-6" a small can of glue,roll of aluminum tape, all pieces have a slip joint on one end that can be glued together.
I pushed the 12" piece in first followed by 2-6" pieces with a little glue as close to the center as I could, as I finished each one I did the paper towel test, it almost sucked it out of my hand!
Finished all four returns and we were amazed with the difference in air movement!
I then proceeded to remove each register where I noticed they were sticking up into the duct within a 1/2" of the top, I took a tape, measured from the ceiling face up into the duct 1/4" and cut the stub off. Once I got all of them cut we noticed the temp was coming down, a lot!
I have 5 more registers coming, I will cut out and install till I think I have any hot spots covered!

[TheKothes]

My return air suction is horrible as well. I was told by the dealer when I took it to them for service to check the air they removed both units from the roof and "fixed" the duct work so it would perform better. It sounds to me this was a band-aid and they have just fallen back down. Thanks for the information! I will be making a trip to Home Depot today after I investigate my situation more closely. I will report back what I find.

[Good Life]

You need to look at this as well!

http://www.montanaowners.com/forums/...ad.php?t=71861

[TheKothes]

Installed the PVC and cleaned out the sawdust. Tied up the wires as well. It is noticeably louder which tells me there is more air flow. We will find out on the next venture.