Question about running the Cabin AC while traveling

I think the drain stoppers in the sink when moving is a good idea to help control odors.

It didn't splash OUT of the sink, it sloshed around and went down the drain pipe.

Oh I see what you are saying now. You're saying the p-trap drained itself. I guess it's possible you might bounce around enough to drain the p-trap enough to let air pass through.

Steve

maillemaker,

It didn't splash OUT of the sink, it sloshed around and went down the drain pipe. :) (Though upon rereading, I probably should've written "splashes out of the p-traps used on the plumbing for the sinks.) Just saying that it NEVER happened if the windows are all closed up, but did happen a few times early in our ownership when I tried driving with the windows & vents open instead of running the A/C.

Others on these forums have also noticed this same issue with their rigs, so I know we're not alone. I don't see where it's that unrealistic after driving several hours down the roads, the water will slosh quite a bit. Or, perhaps where you live, the roads are all smooth and straight?! Not so here in New England. :)

Anyway, what we have also done to pretty much eliminate the issue is to make sure the stoppers for each sink are inserted into the drains.

Just trying to pass some helpful hints along to folks who might also have the problem.

~Rick

If the water splashes out of the p-traps in the sinks while you're trucking down the road

Man, what are you driving over that would make water jump all the way out of your plumbing and clear the sink countertop?!?!?

There is no way any water should come out of your p-traps during normal operation of your RV, except, possibly, from evaporation if the RV has sat for a while. And even if it did somehow splash out of the p-trap, it would end up in your sink basin or shower basin and then drain right back down into the p-trap.

If the water is completely clearing the p-trap and your sink/tub basin, more than likely your RV is tipped over on its side and you have bigger problems. :)

Steve

snowdance wrote:
Intresting you never open any vents and windows. Must have real bad mildew like many we see.

We keep the motorhome closed up only when going down the road ... to keep dust, pollen, smoke, and smog out. We do the same in our personal vehicles when going down the road.

When we are camped with the RV and when the RV is in storage in the back yard ... we have the roof vents open year round (we have roof covers over them) for good air circulation and also keep the roof fan set on automatic so it comes on to draw air through the motorhome whenever it gets above about 80 degrees inside the RV.

The only time we've had mildew in an RV was years ago when we kept an old one in storage in the back yard all closed up during the winter rains and didn't open it up to air out after the rains. :)

I think somebody asked in this thread... At least in theory, the "dash air" in a typical vehicle approaches 20,000 btU. Call it "ton and a half." I recall discussing the capacity of automotive A/C compressors and if recall's working some were rated 22,000. That's a LOT (I refuse to imply a pun and say "a ton") of A/C, but automotive wants quick cooling that can overcome lots of heat absorption from glass and metal, along with losses to the air while moving.

pnichols wrote:
Also, with a vent open in the rear of the motorhome and the dash A/C running in normal mode where outside air is constantly being brought in - not recirculation mode where inside air is constantly used over and over - you are allowing air coming from outside in front of the vehicle to be constantly flowed throughout the motorhome and out the rear vent.

This means your entire motorhome is slowly but surely getting dusty from the constant flow of air from the outside. We keep all of the motorhomes windows and vents closed when traveling to minimize dust in the motorhome and then primarily use the dash A/C in recirculation mode.

Of course the coach's rooftop A/C system only recirculates air, so it doesn't introduce any new dust into the motorhome.

We have always opened vents in our rigs for fresh air to get rid of the humidity from showers, cooking ect. Intresting you never open any vents and windows. Must have real bad mildew like many we see. We also find doing a little dusting to be a minor job.

I did put a hepa filter on the intake of our truck heat and AC. It was a minor job.

Rick Jay wrote:
snowdance,

Your idea has some merit, but there can be a catch. Running with a window or vent open in the rig creates a low pressure area inside. If the water splashes out of the p-traps in the sinks while you're trucking down the road, this low pressure can cause the gray tank odors to be drawn into the rig via the air admittance valves in the plumbinb. And trust me, the gray tank can smell just as bad as the black thank! LOL :) Now if your rig doesn't use the air admittance valve(s), then there's no problem with your method.

In a longer motorhome, though, the lowly chassis A/C won't be able to keep up in hot weather regardless.

~Rick

Intresting but in our 48 years of using RVs and always keeping a vent open even when parked in storage, we have never had the water splash out of the p-traps used on our rig at any time. You must have some special type of P-traps. Intresting to hear reasons people do things..

Also, with a vent open in the rear of the motorhome and the dash A/C running in normal mode where outside air is constantly being brought in - not recirculation mode where inside air is constantly used over and over - you are allowing air coming from outside in front of the vehicle to be constantly flowed throughout the motorhome and out the rear vent.

This means your entire motorhome is slowly but surely getting dusty from the constant flow of air from the outside. We keep all of the motorhomes windows and vents closed when traveling to minimize dust in the motorhome and then primarily use the dash A/C in recirculation mode.

Of course the coach's rooftop A/C system only recirculates air, so it doesn't introduce any new dust into the motorhome.

snowdance,

Your idea has some merit, but there can be a catch. Running with a window or vent open in the rig creates a low pressure area inside. If the water splashes out of the p-traps in the sinks while you're trucking down the road, this low pressure can cause the gray tank odors to be drawn into the rig via the air admittance valves in the plumbinb. And trust me, the gray tank can smell just as bad as the black thank! LOL :) Now if your rig doesn't use the air admittance valve(s), then there's no problem with your method.

In a longer motorhome, though, the lowly chassis A/C won't be able to keep up in hot weather regardless.

~Rick