Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
 

Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > MOC Technical Forums > Montana Problems, Problem Solving & Technical Help
Click Here to Login

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-21-2021, 02:18 PM   #1
Windermere Campers
New Member
 
Join Date: Jan 2018
Location: Windermere
Posts: 4
M.O.C. #21109
Air Flow Issues

I have 2017 3950BR. We live in Florida and camp all year. During the summer the a/c has a difficult time keeping up. Per forum recommendations I have tried removing a/c vent covers to let a/c flow better. Helps but still not great. I have seen a lot of posts about crushed ducts. I checked that today. Nothing seems crushed. I have read numerous strings that inserting a 1 1/2 inch pvc pipe may help. Several questions:

1. Should I insert the pvc pipe into the vent or the return or both?

2. I bought some 1 1/2 inch pvc pipe but it is thick and non-flexible so how long a piece do you recommend inserting? My a/c vent only has a 3-4” diameter hole and my return in rectangular about 12x4? I only ask because my 1 1/2 pipe will not bend so I am limited on the length of pipe.

3. Do you insert the pipe at the opening or try to push in far into the vent?

4. Most stores sell schedule 40 pvc pipe. Should I be using that or something thinner.

5. If inserting pipe doesn’t work any other suggestions? Thanks in advance.
Windermere Campers is offline   Reply With Quote
Old 02-21-2021, 03:39 PM   #2
Golfmedik
Montana Master
 
Golfmedik's Avatar
 
Join Date: Apr 2016
Location: Auburn
Posts: 844
M.O.C. #18474
Quote:
Originally Posted by Windermere Campers View Post
I have 2017 3950BR. We live in Florida and camp all year. During the summer the a/c has a difficult time keeping up. Per forum recommendations I have tried removing a/c vent covers to let a/c flow better. Helps but still not great. I have seen a lot of posts about crushed ducts. I checked that today. Nothing seems crushed. I have read numerous strings that inserting a 1 1/2 inch pvc pipe may help. Several questions:

1. Should I insert the pvc pipe into the vent or the return or both?

2. I bought some 1 1/2 inch pvc pipe but it is thick and non-flexible so how long a piece do you recommend inserting? My a/c vent only has a 3-4 diameter hole and my return in rectangular about 12x4? I only ask because my 1 1/2 pipe will not bend so I am limited on the length of pipe.

3. Do you insert the pipe at the opening or try to push in far into the vent?

4. Most stores sell schedule 40 pvc pipe. Should I be using that or something thinner.

5. If inserting pipe doesnt work any other suggestions? Thanks in advance.
The vent "mod" required for the '16-'17 rigs is talking about putting 1 1/4" Inside diameter pipe in the return vents as the units could not breathe. The 1 1/4" has an outside diameter of 1 1/2" that equals what the duct size should be. Usually the opening size of the return vents are around 9" so I cut mine at 9" lengths and inserted them lengthwise to the rig and then turned them to point the direction of the airflow. That way the air flows through the pipes. I put one on either side of my ducting on one side but the other side was so severely crushed that I had to put three on that side as one went in the middle. Also, remember to do the front AC unit too! I then ordered JR Products vent covers/vents as they had larger openings for airflow, but you can always cut out every other directional vent on the cover to give you more flow.
__________________
2020 Montana 3790RD Legacy EditionOnan, TST TPMS, TrailAir pin, Discs,
2013 F350 DRW 4x4 CC LBViair 10007, Ride-Rites, Westin HDx, 12k Smittybilt
Golfmedik is offline   Reply With Quote
Old 02-21-2021, 07:48 PM   #3
DQDick
Site Team
 
DQDick's Avatar
 
Join Date: Jun 2011
Location: Wilsey
Posts: 17,970
M.O.C. #11455
One more thing I did was to cut down the fixture that holds the vent covers so that it matched the height of the ductwork. Before that they proturded into the ductwork blocking some flow.
__________________
Dick, Joyce, Diego, Picatso and Gustav
2017 3720 RL, and 2013 HC 343RL
2017 3500 Dodge Maxi DRW 4X4, Pullrite Hitch, IS, Disk Brakes, 3rd AC, Winegard Traveler, Bathroom door mod, Dometic 320, couch for desk swap, etc.
DQDick is offline   Reply With Quote
Old 03-03-2021, 04:36 PM   #4
Windermere Campers
New Member
 
Join Date: Jan 2018
Location: Windermere
Posts: 4
M.O.C. #21109
Thanks for the reply. Can you send me the information for the JR Products vent covers?
Windermere Campers is offline   Reply With Quote
Old 03-03-2021, 05:54 PM   #5
Daryles
Montana Master
 
Daryles's Avatar
 
Join Date: May 2019
Location: Alton
Posts: 949
M.O.C. #24086
Cover your stair vents.
I always say don't cover them because they are the furnace air returns BUT, for the summer, cover them. Also get magnet vent covers for your floor air registers. Trap all the cool dehumidified air inside your cabin.
Just don't forget to take these all off if you have to run the furnace.
__________________
Daryl and Marianne,
2019 3130re 20th Anniversary Edition
2016 F350 Lariat
Daryles is online now   Reply With Quote
Old 03-03-2021, 06:21 PM   #6
Daryles
Montana Master
 
Daryles's Avatar
 
Join Date: May 2019
Location: Alton
Posts: 949
M.O.C. #24086
I was going to wait until closer to the summer to share this but some of you could use this info now...
Window film test
I have frameless windows with dark tint.
The problem is, the sun heats the glass, the aluminum frame conducts the heat right through to the inside of the RV and the frame gets so hot you cant touch it.
Putting reflective window film on the inside, I believe, is not effective. You need something to reflect the heat away before it gets in. OR shade the window entirely (awnings being best solution).
I ordered one silver and one bronze (matches my color scheme) reflective interior cling window film. I wanted something removable so I could put it on in the summer, to keep the sun/heat out. Then remove it in the winter, to let the sun in to warm the RV.
I put the film on the outside of the glass to reflect the heat away. I put silver on the left window, bronze on the right side and shade the top right side to compare all four (silver, bronze, shade, full sun).
Note: the film is made for window INTERIOR not exterior. Not my best work, lots of bubbles, after all, this is just a test.
RV rear window is facing due west. Test was done at 3pm under full direct sun. Outside air temperature 88F.
Area:
A= full direct sun
B= shade (white towel)
C= bronze reflective film
D= silver reflective film
Temperature measured on the window FRAME on the INSIDE of each area using a laser thermometer.
A= 130 F
B= 99 F
C= 107 F
D= 105 F

Not that much difference in temperature between bronze and silver. Bronze does go with our color scheme so we will go with that for all windows that do not have awnings. I guess we will wait and see how long this cling film lasts. I'll let you know...
Installed 9-5-20.
Bronze film came off 10-29-20. But, full disclosure, I did not trim off the excess film (zoom in on the bottom right corner and you can see how much was overhanging) so it flapped a lot going down the road and eventually came off.
The silver film which was trimmed to the window edge is still firmly attached (3-4-2021). I'm guessing the bronze would still be attached if I had trimmed it properly.
Attached Thumbnails
Click image for larger version

Name:	Reflective window film.jpg
Views:	6
Size:	214.2 KB
ID:	8596  
Daryles is online now   Reply With Quote
Old 03-03-2021, 07:56 PM   #7
Rondo
Site Team
 
Join Date: Aug 2007
Location: Omaha
Posts: 6,300
M.O.C. #7560
I don't have any photos of the shades we put on but while in AZ two years ago we ran across a couple that make and install window shades/screens that snap onto the outside of the windows. They come in multiple colors so you can decide on the color you want to use. They are screens that have thin wire filament running through them and that filament captures and expels any heat the sun puts on them. It's dark out presently but will check out the name of the company/couple that makes them and post it on this post tomorrow or Friday. They really work and the Monte can sit out in the blazing hot summer sun and still remain cool inside with just the main living room A/C running.
Rondo is offline   Reply With Quote
Old 03-10-2021, 05:00 PM   #8
Golfmedik
Montana Master
 
Golfmedik's Avatar
 
Join Date: Apr 2016
Location: Auburn
Posts: 844
M.O.C. #18474
Quote:
Originally Posted by Windermere Campers View Post
Thanks for the reply. Can you send me the information for the JR Products vent covers?
https://www.walmart.com/ip/JR-Produc...hite/198742002
__________________
2020 Montana 3790RD Legacy EditionOnan, TST TPMS, TrailAir pin, Discs,
2013 F350 DRW 4x4 CC LBViair 10007, Ride-Rites, Westin HDx, 12k Smittybilt
Golfmedik is offline   Reply With Quote
Old 03-10-2021, 07:26 PM   #9
R.S.O'Donnell
Montana Fan
 
Join Date: Feb 2020
Location: Nomads
Posts: 289
M.O.C. #25842
Quote:
Originally Posted by Rondo View Post
I don't have any photos of the shades we put on but while in AZ two years ago we ran across a couple that make and install window shades/screens that snap onto the outside of the windows. They come in multiple colors so you can decide on the color you want to use. They are screens that have thin wire filament running through them and that filament captures and expels any heat the sun puts on them. It's dark out presently but will check out the name of the company/couple that makes them and post it on this post tomorrow or Friday. They really work and the Monte can sit out in the blazing hot summer sun and still remain cool inside with just the main living room A/C running.
We have them too. Windows and frames were so hot before you couldn't touch them. Shades were a total game changer. We can only run one AC on our generator. Before we put the shades on it didn't seem to do any good at all. Now we can walk the temperature down easily with just one AC running.

We wintered over in Quartzite this year. These guys were everywhere.

https://www.shadepro.net/product/window-cover/
R.S.O'Donnell is offline   Reply With Quote
Old 03-28-2021, 09:37 AM   #10
PND Mountaineer
New Member
 
Join Date: Mar 2021
Location: YAKIMA
Posts: 8
M.O.C. #28460
What make is the AC units?
PND Mountaineer is offline   Reply With Quote
Old 03-29-2021, 06:08 PM   #11
Windermere Campers
New Member
 
Join Date: Jan 2018
Location: Windermere
Posts: 4
M.O.C. #21109
Dometic
Windermere Campers is offline   Reply With Quote
Old 03-29-2021, 08:11 PM   #12
PND Mountaineer
New Member
 
Join Date: Mar 2021
Location: YAKIMA
Posts: 8
M.O.C. #28460
RVAirflow has a kit for the Dometic Brisk Air II. That is what I have.
PND Mountaineer is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 05:04 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×