Roof AC units on, Roof fans/vents open or closed?

rockhillmanor wrote:
Closed.

Or as our parents used to say "shut that door you want to cool the whole neighborhood?"! :B

And by the way. If you are in Florida you NEED to get RV vent pillows to put up in the closed vents. Buy the ones with the silver on one side and sheepskin type covering. Foam ones are junk and look tacky too.

They will cool your RV down about 10 degrees or more. Those plastic vents are not air tight and along with the clear or white cover heat bears down in and the ac escapes.

I have three roof vents and once I put those pillows in all of them, ahhhh what a difference. They also will keep cold out and heat in during the winter months too.





I don't leave home without them.

Did the vent pillows come with the rv or did you make/buy them? I'm new to all this and still looking for our first.

JaxDad wrote:

ArchHoagland wrote:
Always close the roof vents and windows when you are running the air conditioning whether it be parked or moving down the highway.

The air conditioners bring their air in from the interior of the coach. If you leave the vents open then you are drawing in hot air.

Actually that's wrong.

Unless the dash a/c is set to 'max' or 'recirculate' the system cools outside air and vents stale air. All vehicles operate this way.

As for cooling efficiency, if you leave the rearmost roof vent open (hot air rises) and set the dash a/c to highest fan and set to blow down the back the hotest air will be drawn out the roof and the cooled air will be drawn towards the back to cool the rest of the coach.

I've been doing this for years and have proven how well it works to many non-believers over the years.

On a typical dash unit the blower fan is the weak part and it usually can't keep up with the cooling capacity of the rest of the system. This method dramatically increases air flow and really helps.

I believe (but I could be wrong) this thread is referring to roof AC's with vents open/closed. Otherwise I agree with you, if I can be comfortable with only dash AC I'll also leave a rear vent open to allow warmer air out. I also have vent covers otherwise I think traveling with an open unprotected vent is not a great idea.

I agree with vents closed with a gas MH, but maybe not with a DP. I rarely have to run my generator/roof ACs as my dash AC will do the job up to about 95 outside. It is recycling/cooling the air from under the dash, not from the ceiling like a roof AC. I leave the vents open in the back of our DP to help get the engine heat out with a small window open on the shady side.

If I think it will get hot enough out I'll turn the front AC to on so all I have to do is crank the generator with the dash switch for additional AC. Usually it's not long enough to bother closing the roof vents.

If I am stopping at a CG when it's still really hot out I'll have the DW turn on another one/two roof ACs and try and cool most of the coach down before hooking to shore power.

ArchHoagland wrote:
Always close the roof vents and windows when you are running the air conditioning whether it be parked or moving down the highway.

The air conditioners bring their air in from the interior of the coach. If you leave the vents open then you are drawing in hot air.

Actually that's wrong.

Unless the dash a/c is set to 'max' or 'recirculate' the system cools outside air and vents stale air. All vehicles operate this way.

As for cooling efficiency, if you leave the rearmost roof vent open (hot air rises) and set the dash a/c to highest fan and set to blow down the back the hotest air will be drawn out the roof and the cooled air will be drawn towards the back to cool the rest of the coach.

I've been doing this for years and have proven how well it works to many non-believers over the years.

On a typical dash unit the blower fan is the weak part and it usually can't keep up with the cooling capacity of the rest of the system. This method dramatically increases air flow and really helps.

Side note about leaving roof vents open even just a little bit with out a shroud over them while traveling......they WILL blow open if not closed all the way AND they will crack clean off.

Been there done that on my first newbie trip eons ago.

wallynm wrote:
Swamp cooler window cracked open a bit. Refrig everything closed. Shades down

X2

I had to get edgecated real fast when I hit the south! :B

I am from the Midwest. RV'ing during the summer months is simply NOT a problem. The AC will keep the inside cool.

BUT....once you hit the mason Dixie Line you have to get very creative on how to keep your coach cool and the temps down. The AC just can't keep up.

I have dogs traveling in the coach so it was imperative that I figure out how to keep it cool and safe for them.

I not only put all the shades down I put van sun shades underneath them. They fit perfectly no velcro needed and when not in use they come right out and fold up for storage. This also brings the temps down while traveling during the hottest part of the day.

And when the temps get real bad I will also cover the skylight in the shower. BOY does the heat come thru that!

Swamp cooler window cracked open a bit. Refrig everything closed. Shades down

RJL wrote:

Winnebago Bob wrote:
If you are running in AC mode, then I would leave the roof vents open just long enough to purge 'hot' air, then closed to contain cool air.

My thoughts EXACTLY Bob. Thank you.

:)

Same thing I do in the car. AC doesn't get cold for a minute or two. By the time I'm through two traffic lights and heading toward the interstate, we're good!

Winnebago Bob wrote:
If you are running in AC mode, then I would leave the roof vents open just long enough to purge 'hot' air, then closed to contain cool air.

My thoughts EXACTLY Bob. Thank you.

rockhillmanor wrote:
Closed.

Or as our parents used to say "shut that door you want to cool the whole neighborhood?"! :B

And by the way. If you are in Florida you NEED to get RV vent pillows to put up in the closed vents. Buy the ones with the silver on one side and sheepskin type covering. Foam ones are junk and look tacky too.

They will cool your RV down about 10 degrees or more. Those plastic vents are not air tight and along with the clear or white cover heat bears down in and the ac escapes.

I have three roof vents and once I put those pillows in all of them, ahhhh what a difference. They also will keep cold out and heat in during the winter months too.





I don't leave home without them.

Great tip and thank you all for the advise. No I dont leave the windows open at my house but my thinking was maybe we should travel a bit with vents open to allow for the hot air to get sucked out. Gonna get some of those pillows before this coming summer, Thank you.