Vent pillows

If you're really worried about heat build up, flip them over and put the reflectix inside. I always store my pillows in place and have never had any problems. We live in Phoenix, AZ.
RichH

I’ll be interested to read the consensus on this. I thought the vents were for leaving open in hot weather storage. Of course you need exterior vent covers. The hottest air will always exit if they are open. I would only use the pillows while I was running the AC. Fading from the sun seems a lower issue to me than allowing heat to build up unchecked.

They block noise as well as insulate during colder temps. I would use them in the winter as an insulator while leaving one vent partially open to vent inside air to lower the chance of condensation.
While in storage or parked in my driveway, I open all vents with covers to allow air to exchange because i'm not concerned about what temp it is inside the rv.

I bought one of those pillows too, unfortunately it was for our bedroom vent that has a fantastic fan in it, and it barely fits, and falls out over time. I bought it to block out the morning sun, so keeping the morning sun out, but gave up on it, and finally just painted the black vent cover white which works good. I would not consider keeping the pillow in the vent during storage. I believe it would do more harm than good. I open 2 vents both with covers during storage

suprz, if you ever have the need, Lance (part of the arctic package) makes a snap in place vinyl interior cover. 4 snaps get screwed in place in the 4 corners on the inside trim. The 14x14 vinyl pad gets snapped into place. They do a good job of insulating as well as blocking out sunlight. You can also unsnap two snaps and tuck it under itself to only cover 1/2 of the vent, allowing partial ventilation if needed.

We use the vent covers for ac, heat, and to block light as well. During storage we keep so there off for air circulation, but only an inch during winter time.

I have them now for years and only use them during winter I.E. hunting season. I do not use them in the summer

When I store my RV I keep the roof vents open to allow circulation of air. Plugging them with a block of foam would prevent that.

We have three vents, just put one up front. I have pillows in the front and back but the bathroom vent stays open all the time. It also has the cover the other two don't. I like the Reflectix idea I'll do that before our next trip.