There were gaps at the corners of the factory mattress in our Grandby and you will get airflow. Cut to fit the HyperVent after pulling out the bed slide so the HyperVent butts up against the 1/2 plywood of the slide. Lift the HyperVent and mattress and push the slide in. Do you have the factory mattress? I was able slide my fingers between the sides and also had a gap along the front. You don't need much as it acts like a Chimney and will pull airJon R said:I have a question about using Hypervent in the over the cab area: On my camper, the mattress and cushions fit very tight to the walls and slider end board. I can see Hypervent maintaining an air space, but there will be no way for air to flow and carry away moisture because the edges are all closed tight. Does Hypervent still prevent condensation in this type of installation, or does it just hold the mattress above the water until you wipe it up?
You will have problems without HyperVent if you camp in cold temperatures. You will get airflow. The alternatives are wet bedding and mold. We had gaps in our 2014 Grandby. It doesn't take much. Better safe then sorry. The area for the HyperVent is over the overhang only, not the pull-out portion. I can't believe that you don't have some space. If you can slide your fingers down between the wall and mattress you will be fine. You can take scraps that are left over and install then on the sides if you have a concern.Jon R said:I have the factory mattress and the king bed option in my 2021 Grandby. The mattress and cushions fit very tightly on mine with no open gaps anywhere. I could be wrong, but I don’t see how much airflow could occur.
rando said:Maybe an insulating layer of ensolite foam on the bed platform to keep the surface a little warmer and above the dew point, followed by hypervent or froli springs would work to prevent condensation all together?
From reports of people who's mattress is tight against the overhang bottom would indicate that moisture is being driven through the mattress. So yes, the mattress has moisture trapped in it.rubberlegs said:Our FWC mattress bottom is vinyl. I’ve never noticed any moisture, but it seems many others do. Wonder if there is moisture inside the mattress?
Me too, but I want to be on the safe side, so I leave it unmade to air out for about 16 hours per day.JaSAn said:Even at home I leave the bed unmade for a couple of hours to let the mattress air out.
We've wondered why we haven't found moisture, and the reason is because we didn't look in enough places. Today I unzipped the foam inside the mattress. The cover is vinyl on the bottom. Yup, plenty of mold in the foam.JaSAn said:From reports of people who's mattress is tight against the overhang bottom would indicate that moisture is being driven through the mattress. So yes, the mattress has moisture trapped in it.
Even at home I leave the bed unmade for a couple of hours to let the mattress air out.
yup, mattresses can be super expensive. After we got our new ones for megabux, I had no problem springing for the also expensive hypervent to put under it. We were recently camped out in sub freezing temps for 10 days and the cabover surface under the hypervent was SOAKED, but the mattress stayed dry.rubberlegs said:We've wondered why we haven't found moisture, and the reason is because we didn't look in enough places. Today I unzipped the foam inside the mattress. The cover is vinyl on the bottom. Yup, plenty of mold in the foam.
Reading online, there's advice on hydrogen peroxide, vinegar, baking soda... has anyone dealt with this before? We looked into a new (softer) pad a couple months ago, and the cost was a bit of a shock to this cheapskate.
Speaking of moisture, we had a lot of it on a recent trip, and one of the ceiling light strips got pretty wet. It wouldn't turn off. Good thing it was easy to unplug.
I love this and would have no problem with putting it up and taking it down. Great idea! Please update once this is field tested.ckent323 said:Somehow I posted the following comment to the wrong thread (not sure how I accomplished that!). Anyway I deleted it there and am reposting here (this expands upon what I have previously posted about this idea).
As has been mentioned before, campers are prone to condensation issues in cold damp weather conditions.
The best place for vapor barriers and insulation is on the cold side of a wall to minimize condensation inside. Unfortunately the insulation blankets typically added to our campers is on the inside.
I have fabricated but not yet tested a green canvas "tarp" that snaps onto the exterior side of the roof and extends down to the Aluminum sides (which we all know have minimal insulation). It has a pocket all around on the camper side of the "tarp" to accept bubble wrap,or similar insulating materials (solid foam will fit but it is bulky and a hassle). I replaced a few screws around the sides of the camper roof with screw-in snaps and put the appropriate mating snap on the tarp in the appropriate locations.
This puts the insulation (in the pocket of the tarp) on the exterior side of the pop up material (on the cold side) between the outside surface of the tarp and the pop-up side material and should help minimize condensation on the interior surfaces of the pop-up material. Further, it does not 'hide' or trap condensation on the interior surfaces and makes wiping them if there is condensation easier.
The downside is that is has to be installed and removed when raising or before lowering the camper roof and then be stored inside the camper. The snaps make the installation and removal easy. SInce the insulating bubble wrap material does not compress the rolled up tarp with insulation does consume a lot of space when stored.
I suppose some kind of inflatable/deflatable bag (similar to an air mattress but with thinner material) could be used instead of bubble wrap and that would allow compressing the tarp and insulation (after the bag is deflated) to a smaller size for storage.