Blocking/Redirecting AC Flow

[edmck]

This subject has probably come up before but so far I've been able to locate the right threads. I'm down here in Tucson riding out this Covid crisis and the temps in the past couple of days have been north of 100 degrees. While its comfortable enough in my 3100RL, I've been wondering if it's okay to block the front bedroom ceiling vents during the day in order to force more cool air back into the main living area. I've read on several non-RV sites that this can cause damage to an AC unit — is that still true in a ducted AC system like mine? Seems like this might be a good idea but I'm reluctant to do anything I might later regret. I'd love to get some expert opinion on this from the group. Many thanks.

[Jamesb]

I hope it doesn’t damage anything, I blocked all mine off in the master bed to get more air to the rear. Seems to work, but didn’t make as big as difference as I was expecting. It’s been like that for one season.
Interested in someone else’s knowledge too.

[DQDick]

Do not block any off. If you check with Dometic you will find that the number of supply vents Keystone put in are the absolute minimum. (this is also true of the furnace) The way to get more cold air where you want it is to take the supply vent covers down (three tabs) and remove everyother fin. Folks don't even notice until they come over to ask about our rig being cooler and I point them out. Also, if you're in the south west you might want to consider the third AC unit and some type of covering for your windows.

[AZ Traveler]

Ed,

I agree with Dick. Keep them all open. The cool air will flow down the stairs. Our air has no trouble keeping up here in AZ with our dry air. Close your shades if you are getting a lot of solar heating from the sun. We had our first 100 deg day yesterday and we are yet to turn our a/c on at home.

[Texan]

You can also buy vents that have the fins spaced further apart at PPL. Also you may want to cut you 2 - 1 1/4'' pvc about 9'' long and insert one in each return air vent for better air circulation as these vents many times collapse right at the vent. You could check all your a/c vents to make sure they are opened enough inside the vent for free air flow and if not then also add pvc pipe to these also. You could also add a couple of vents in your ceiling for better air distribution. I've thought about adding one to the kitchen and one in the living room. After trying all this then the 3rd a/c is always an option as has been suggested.

[Dave W]

I put a bunch of these vents in to modulate and redirect a/c flow. They have worked great. IIRC, I paid around 12 bucks each then, unfortunately they cost more now: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Daryles]

Depending on your model year, early models (2017??) had issues with collapsed air ducts restricting airflow.
They fixed that in later models with ridgid foam duct work.
Also try
Cover floor registers and stair vents. Trap cold air inside the RV, vice letting it escape into the basement.
Floor register magnetic covers
https://www.walmart.com/ip/8-x-15-Ma...pack/505784740
Also try
https://www.shaderv.com/

[Dave W]

Originally Posted by Daryles

Cover floor registers and stair vents. Trap cold air inside the RV, vice letting it escape into the basement.
Floor register magnetic covers

https://www.shaderv.com/

I changed the floor registers out to modulating - from Lowe's. Home Depot didn't have them.



Can you guess that I like to control where the a/c or heat go



That shade is interesting but I would bet that a good wind would turn it into a sail - but no longer attached to your RV

[McRod]

I am also in Tucson and the 100 degree weather started early this year...no end in site. Seems the first 100° weather and Saguaro blooms go hand-in-hand.

I am 100% off grid with my rig and I don't keep any AC vents closed. My rig is also 100% in direct 🌞 sunlight. I have spent quite a bit of time doing various insulation projects over the years.

Windows and window frames are a big area that conduct heat into the RV. I have double pane windows but added EZSnap shades on the outside of the rig and they help ALOT. I also have my rig nose pointed east, and I put my awnings out to ensure they at least shade the full south side of the RV. I don't usually put them all the way out, rather, only extend them about two feet. This helps with any random wind gusts.

Inside I use MCD day night shades to keep out the heat. I stuff the fantastic vents with a 4" Camco RV Thermal vent insulator foam pad that also has reflective surface on one side.

Inside every cabinet, I have added 1-1/2" rigid foam that I covered with felt. This reduces the cabinet temps by about 10°.

I have slide toppers above every slide.

I bought a 3rd 110v portable 12k AC unit from Lowe's last year. I have not used it yet, but today it was 100° outside and got up to 81° inside the RV with my 2 ACs. Would have probably been hotter, but we did have some cloud cover today. It's not so much the outside temp but rather the sun's intensity that heats things up. Cloud cover helped alot.

I keep my infared thermometer gun nearby and I am constantly looking for hotspots.

[kc8lvy]

I bought the same ones as Dave W. It made a big difference. On hot days I also run a fan to help circulate the cold air.

[uhftx]

The ones I have which are old. But they will rotate.
Heat rises and the cooler air will settle back into the kitchen and living areas.

They can not have changed that much over the years. I rotate them to where I like the air to flow. Away from the intake in the unit.

I like the Idea sugestion of covering the floor registers, to keep the cool air inside the main living space.

I have also had a freezing loss of cooling within the AC unit. Shut it down and wait for thaw and restart. Normally in a high humid conditions.
The window coverings are a great suggestion also along with shade for the AC unit itself to keep the sun beating down on the unit.

Simple solutions and a little ingenuity go a long way from our forum help to others.

Thanks for all the helpful contributions/suggestions.

[AZ Traveler]

Originally Posted by McRod

I am also in Tucson and the 100 degree weather started early this year...no end in site. Seems the first 100° weather and Saguaro blooms go hand-in-hand.

I am 100% off grid with my rig and I don't keep any AC vents closed. My rig is also 100% in direct 🌞 sunlight. I have spent quite a bit of time doing various insulation projects over the years.

Windows and window frames are a big area that conduct heat into the RV. I have double pane windows but added EZSnap shades on the outside of the rig and they help ALOT. I also have my rig nose pointed east, and I put my awnings out to ensure they at least shade the full south side of the RV. I don't usually put them all the way out, rather, only extend them about two feet. This helps with any random wind gusts.

Inside I use MCD day night shades to keep out the heat. I stuff the fantastic vents with a 4" Camco RV Thermal vent insulator foam pad that also has reflective surface on one side.

Inside every cabinet, I have added 1-1/2" rigid foam that I covered with felt. This reduces the cabinet temps by about 10°.

I have slide toppers above every slide.

I bought a 3rd 110v portable 12k AC unit from Lowe's last year. I have not used it yet, but today it was 100° outside and got up to 81° inside the RV with my 2 ACs. Would have probably been hotter, but we did have some cloud cover today. It's not so much the outside temp but rather the sun's intensity that heats things up. Cloud cover helped alot.

I keep my infared thermometer gun nearby and I am constantly looking for hotspots.

100 degrees is a perfect day here in Southern AZ.

[McRod]

Originally Posted by AZ Traveler

100 degrees is a perfect day here in Southern AZ.

It was 99° inside my RV today when I got home....had to sit outside, drink a beer and watch the sunset while the ACs cool down the inside. Tough times...I tell ya!

[Cowboy56]

We set a fan in bedroom and point to living area with both ac running and bedroom ac only main opened it helps a lot here in Yuma right now stuck here also because of covid 19

[ejerni]

My suggestion is to buy a fan. We did for our Monty and it helps to push the air from the back ac when the ac is on.

[Code80]

We were in Quartzsite until Monday. First we tried pulling in the bedroom slider during the day and bought a small 9x9 fan and directed the air from the bedroom down. That worked a little bit, then we pulled in the ODS slide that helped. I went through the books and couldn't find anything else. Someone in this group said the had a plugged duct, I started at the unit and saw a couple of dog ears next to the return. Bingo that opened up the direct downdraft it roars out of it. We closed the bedroom door and the living area stayed comfortabe. We have a 3610 rl with a single unit. It kept us at 82 inside in 107 outside. Having lived in Palm Springs Ca for 35 years we were pretty happy.

[Buckfisher]

Best plan-leave all vents fully open including the main air dump in the bedroom and use a fan to push air from the bedroom floor into the living area. Restricting air flow reduces the ability of the ac to deliver the maximum amount of cold air.

[daveinaz]

We camping last year in AZ our unit could keep up either. Thought the unit was working right, but the thermometer showed it putting out cold air at the unit. The problem was the roof was so hot that the air traveling through the ductwork up there was hot but the time it came out the vents. Our solution was to have the main unit dump directly down instead of going through the vents, then use a fan to push the air to the bedroom if needed or just close the door to the bedroom during the day. We also had our roof cleaned and coated which helped deflect some of the heat from it.

[Slow Hand]

I have not read all the comments here but here is my observation. If you let one part of your RV get hot that heat will only transfer to other parts of the RV. Heat will transfer better than cool. I only have one AC so I take a fan and stick it in the hall and blow into the living area. That way it evens out the cool in the RV. Also when I get up I turn on the AC and get it as cold as I can. AC has to take all of the heat from everything in the rv to cool it down. Like using the stove in a cool room. How hot will that room get. Your AC can't keep up with that heat. Heat doesn't have to warm things up to make you feel worm just the air. Where AC has to cool down everything. including chairs tables couch. Everything needs to be cool