We have now used our 2016 van Leigh 5th wheel in below freezing temps. The heat loss is just enormous and the heater kicks on all the time through the night. I discovered that there’s about a 1’ x 8’ gap between the basement and the under belly, and there are complete 2 inch holes in the steel frame going into the underbelly which I had previously filled. But the fact that the basement is completely exposed to the underbelly makes me question whether there is direct air coming straight into the basement and then straight into the kitchen with nothing to stop outside air, anyone have any thoughts on this and have you managed a reasonable way of blocking all of this air current from the outside?
The bedroom slide also has a lot of exposed light on either side of the bed that I have tried to block, so if anyone has found a really good solution for that as well.
Are you traveling or fixed location for winter? If fixed look into skirting the unit…
Along with the skirting Jon mentioned, you could use some pipe insulation to help seal along the slide out edges.
There’s some detailed info in this video on the pipe insulation option.
Thanks. I am in a fixed location for now, and these are all good suggestions thanks. But I’m talking about a direct access of air going through the holes in the frame and going directly into the underbelly and then there’s this huge air gap between the underbelly in the basement. In other words, I think the whole insulation thing is kind of a joke. If you’re going to have direct air passage going into an area that goes directly into the living area underneath the kitchen cabinets there is a direct connection to the basement that allows air to flow directly in and out… I’m gonna try to work on getting those gaps closed, but I think it’s a major design flaw to allow the underbelly to be exposed directly to the interior especially if you haven’t sealed up all of the holes that are in the frame. If anybody’s looked at that issue and figured out a simple way to do that, it would be interesting, but I think there’s more airflow coming from there than all of the other places combined. skirting would help with wind, but there’s no way to completely seal that to the ground without a lot of effort and so I really feel like I need to get the interior sealed first.
Don’t forget to cut insulation and place behind the small plastic access doors for the refrigerator ice maker and black tank vent loop access (I assume most units have these panels). The walls have a better thermal rating than the plastic, not by much but every little bit helps.
We stayed in our Vilano 370 GB for 3 winters midlands SC and AL and never froze the piping. We usually ran a small space heater in the front bathroom and used the fireplace heater for the main living area. Those heaters would hold the temperature but not raise it if it was really cold. We used the propane furnace for true warm temperature and to raise the temperature in the mornings. Coldest we stayed in the unit was middle 30s during the day and teens at night. We had a heated water hose and ran a grow light in the wet bay to keep those items warm. Also put insulation in the floor of the wet bay since there are at least 3 opening in it (one for cables and 2 for low point drains). One of the return air registers on our unit uses the interior steps as a return register so make sure to not block those since this is how the storage bay gets heat.
Understand what you’re saying but think about something like these that seal the whole underbelly
These are 3-season rigs and were never designed or constructed for extended stays in below-freezing conditions. I have owned an Arctic Fox and an Outdoors RV, true four-season rigs, and the walls, ceiling, and underbelly were heavily insulated; much more insulation than the Vanleighs.
Skirting the perimeter of the rig will help retain heat. Filling the gaps around the slides with pool noodles or foam pipe insulation will help. If you look carefully, you may find that there is a flexible duct that exits from the furnace and goes into the underbelly to push warm air back toward the fresh and black tanks. Dropping the chloroplast (black plastic cover on the underside of the trailer) will allow you to add wool or fiberglass batts of insulation; close up the chloroplast afterwards. Sealing up every hole or gap in the frame will help keep the heat in (be careful not to block or jam up any moving mechanical parts).
You have to run the propane furnace to heat the plumbing in the basement; electric heaters in the living area won’t heat the basement. There are lots of videos on YouTube that show how others have winterized their RVs