Roof Vents in the Winter

[Craig P.]

The discussion thread going on about insulating roof vent covers in this section brings up a good question about cold weather camping.

I was bored the other day, so I searched YouTube for anything RV related. I came across a library of videos from "RV Geek". He discussed cold weather camping in his videos, and stressed the need to keep the roof vents open in cold weather, to allow moisture to escape. He's not just talking about cooking and bathing moisture, but moisture from just breathing.

Living in California, I haven't done much extreme cold weather camping, but to me it seems counter-productive to run a heater and/or furnace while leaving your roof vents wide open. After all, heat rises. I understand the need when cooking or showering, but all the time?

What do you folks think?

Craig

[96 Wideglide]

I'm a cheap Scotsman. I dont do it !!

[GMRHost]

If you're running your furnace, you're taking out a lot of the moisture, already. Switch to an edenpure-style electric heater, not so much.
While humidity can be a problem, the lack thereof can also be a problem. Too low of humidity, and fabric ages faster, wood dries out, and screws can even come loose. Not to mention you will need MORE heat to feel warm, since there is less moisture in the air to conduct the warmth.
It would seem to me that if the windows were fogging, it might be a good idea. They can be a pretty good barometer.
But that can lead to another suggestion; Get a good barometer, and you can keep closer tabs on your humidity. and adjust the vents accordingly.

[Possum]

Craig,

We're a couple of thousand miles straight north of you on the left coast of BC and winter weather around here usually equates to pouring rain with the occasional snow flurry.

You do not plug the vents or you'll soon be ankle deep in water. A friend new to the storm watching weekends out by Ucluelet or Tofino couldn't figure out where all the water in his motorhome came from and my wife had to explain that the unit has to breathe if you want to stay warm and dry.

[Arch Hoagland]

We keep our rear bathroom vent open with the exhaust fan running on low all night. We crack a front window and allow air to be drawn in through the coach.

We tried not doing that once and our windshield looked like somebody squirted a hose on it. We don't run the furnace at night, just a small electric heater. In the morning we close it up and fire up the furnace.

[Craig P.]

Quote:

Originally Posted by Arch Hoagland We keep our rear bathroom vent open with the exhaust fan running on low all night. We crack a front window and allow air to be drawn in through the coach. We tried not doing that once and our windshield looked like somebody squirted a hose on it. We don't run the furnace at night, just a small electric heater. In the morning we close it up and fire up the furnace.

That's similar to what the guy said in the RV Geeks video. I have two questions re: this procedure. Doesn't running the fan all night pull out all of the warmth that your heater is producing? What is the benefit of running an electric heater vs. the furnace, other than propane savings?

Lastly, at what temps do you find the above procedure necessary?

Craig

[tomwalt]

Last weekend it was in the high 20's or low 30's where I was at.
1) 1st morning I had heavy window condensation. Weather was calm, it was foggy, and frosty outside.
2) 2nd morning a cold front had passed by and no fog, light breeze, but heavy frost. Also no window condensaton.
3) next several days I was on the ocean beach - 40s, windy, no condensation inside.

Observation (no science) - So it seems the humidity/weather outside has a lot to do with condensaton inside. If it is damp and cold outside, you can expect condensation inside.
P.S. 2 adults (my DW might say 1 adult and 1 big child) and 2 small dogs in a 30 foot RV.

[Arch Hoagland]

@Craig P......If the heater wasn't on it would get very cold inside. Hence we turn the heater on to kind of keep the chill off. The furnace would use up all the propane and we don't like it cycling on and off during the night. The fan also acts as a "white" noise that drowns out other campground noises a bit.

We only use the electric heater when temps are down in the low 30's and 40's. Above that we still always run the exhaust fan with an open window until we get up in the 90's. Then only the air conditioner runs at night.

[DonavonP]

Run a small dehumidifier. Removes water and heats the air.

[Senior Chief]

Quote:

Originally Posted by DonavonP Run a small dehumidifier. Removes water and heats the air.

Uh, the dehumidifiers I've owned use an open refrigeration coil to condense moisture out of the air.

I think they make it colder.

[GMRHost]

Quote:

Originally Posted by Senior Chief Uh, the dehumidifiers I've owned use an open refrigeration coil to condense moisture out of the air. I think they make it colder.

It does use the refrigeration coil, but the heat generated by the process is blown across the coils to thaw the ice and make it drain into the tub, so it's really temp-neutral.

[GaryKD]

My roof vents remain closed in the winter. The bathroom vent is open only when showers are taken. As others have posted the furnace, heat pumps, etc take moisture out of the air. I've never had a problem with moisture in the coach.

Lastly, I use the inserts to insulate the roof vent openings from the coach interior. Go to Worldwide Merchandise Company - Vent Cushion - Fan and Vent Accessories - Camping World and read about the product.

[Gerall]

To help with winter cold camping (only lows of 30 here) I use 2" foam cut outs to put into the vents at night. Also I have taken those foam pipe insulator strips and lined the outside crevice of both sliders. Really helps on the draft.

[DonavonP]

IWillTry.org » Blog Archive » Heat your home with a dehumidifier

This guy does a nice job of explaining the net gain of heat with a dehumidifier. Plus you're not letting heat out the roof vent.