window opened

[goots]

Is it alright to have a window opened by the sofa area when traveling down the road or dose your mileage drop??

[Harvard]

valhalla360 wrote:

Healeyman wrote:

TucsonJim wrote:

Harvard wrote:
The open window may cause the water traps in the sinks and shower to burp foul odours.

I'd sure like to understand the scientific reasoning behind this comment.

It's called Bernoulli's Principle. (Google it)

As a vehicle moves through the air, the air moving past the sides/walls of the vehicle create a partial vacuum and will draw air out of the vehicle through any opening.

Evidence of this is that smokers usually slightly open a car window to draw the smoke out of the cabin.

If inside air is being sucked out of an otherwise sealed RV, air will be drawn in through any opening that is of a higher pressure, such as the waste tank vent pipe on the top of the RV.

In it's journey to get to the open side window, the sucked-in air will travel through the waste tank(s) and bubble through the sink and shower "P" traps and into the RV.

In MY RV, when a window is partially open, the door in the vent hood over the stove rattles like the dickens.

Tim

Nice theory but unlikely to have the proposed end result.
- Your vent pipe has the same principal pulling on the other side.
- The pressure difference would have to be fairly dramatic to clear the P-trap.

Reality is as long as it's not a dusty road, there should be no harm and likely not noticeable MPG change.

Assuming the open window area is significantly larger then the vent cross sectional area:

The thought that the vent pipe has the same (but opposite) pressure exerted from the other side would imply that a 3 square foot sail surface on a sail boat has the same propelling force as a 36 square foot sail surface in the same wind. IMO

[goots]

Thank you all for the info

[pconroy328]

1492 wrote:
I think that since your motorhome was never designed to be especially aerodynamically streamlined, and is creating significant amount of drag already, an open window is not going to make any type of noticeable difference in mpg.

I measured it the other day. 9 mpg with the window closed. 8.99999 with the window open. :B

[Terryallan]

glkids2 wrote:
Yes all tanks have vent stacks otherwise the waste flowing into the tanks would essentially hit air dams flowing in and would not drain

My grey tank does not. My black tank does.

[The_Logans]

We always have both of the roof vents open (MaXXair covers on both of them). Keeps the air nice and fresh when traveling. Both our black and gray tanks have their own vent pipes through the roof.

[TucsonJim]

Many RVs don't have a "vent" to the roof so to speak for their gray tank. They have air admittance valves which only allow air to enter the system when there is a demand.

[glkids2]

Yes all tanks have vent stacks otherwise the waste flowing into the tanks would essentially hit air dams flowing in and would not drain

[Terryallan]

valhalla360 wrote:

Healeyman wrote:

TucsonJim wrote:

Harvard wrote:
The open window may cause the water traps in the sinks and shower to burp foul odours.

I'd sure like to understand the scientific reasoning behind this comment.

It's called Bernoulli's Principle. (Google it)

As a vehicle moves through the air, the air moving past the sides/walls of the vehicle create a partial vacuum and will draw air out of the vehicle through any opening.

Evidence of this is that smokers usually slightly open a car window to draw the smoke out of the cabin.

If inside air is being sucked out of an otherwise sealed RV, air will be drawn in through any opening that is of a higher pressure, such as the waste tank vent pipe on the top of the RV.

In it's journey to get to the open side window, the sucked-in air will travel through the waste tank(s) and bubble through the sink and shower "P" traps and into the RV.

In MY RV, when a window is partially open, the door in the vent hood over the stove rattles like the dickens.

Tim

Nice theory but unlikely to have the proposed end result.
- Your vent pipe has the same principal pulling on the other side.
- The pressure difference would have to be fairly dramatic to clear the P-trap.

Reality is as long as it's not a dusty road, there should be no harm and likely not noticeable MPG change.

Do you have a vent pipe for the grey tank???? I'm not sure, But I don't think RVs have vent pipes for the grey tank. Black tank is another thing all together. But since that is sealed from the inside. No odors should be sucked out. I can see it happening to the grey.

As for mpg. Got them great big mirrors hanging off the side. Way more drag than a open window

[valhalla360]

Healeyman wrote:

TucsonJim wrote:

Harvard wrote:
The open window may cause the water traps in the sinks and shower to burp foul odours.

I'd sure like to understand the scientific reasoning behind this comment.

It's called Bernoulli's Principle. (Google it)

As a vehicle moves through the air, the air moving past the sides/walls of the vehicle create a partial vacuum and will draw air out of the vehicle through any opening.

Evidence of this is that smokers usually slightly open a car window to draw the smoke out of the cabin.

If inside air is being sucked out of an otherwise sealed RV, air will be drawn in through any opening that is of a higher pressure, such as the waste tank vent pipe on the top of the RV.

In it's journey to get to the open side window, the sucked-in air will travel through the waste tank(s) and bubble through the sink and shower "P" traps and into the RV.

In MY RV, when a window is partially open, the door in the vent hood over the stove rattles like the dickens.

Tim

Nice theory but unlikely to have the proposed end result.
- Your vent pipe has the same principal pulling on the other side.
- The pressure difference would have to be fairly dramatic to clear the P-trap.

Reality is as long as it's not a dusty road, there should be no harm and likely not noticeable MPG change.

[Healeyman]

TucsonJim wrote:

Harvard wrote:
The open window may cause the water traps in the sinks and shower to burp foul odours.

I'd sure like to understand the scientific reasoning behind this comment.

It's called Bernoulli's Principle. (Google it)

As a vehicle moves through the air, the air moving past the sides/walls of the vehicle create a partial vacuum and will draw air out of the vehicle through any opening.

Evidence of this is that smokers usually slightly open a car window to draw the smoke out of the cabin.

If inside air is being sucked out of an otherwise sealed RV, air will be drawn in through any opening that is of a higher pressure, such as the waste tank vent pipe on the top of the RV.

In it's journey to get out through the open side window, the sucked-in air will travel through the waste tank(s) and bubble through the sink and shower "P" traps and into the RV.

In MY RV, when a window is partially open, the door in the vent hood over the stove rattles like the dickens.

Tim

[robsouth]

Left a widow on my trailer open a little once. Trialer full of dust upon arrival. Just a thought.

[goots]

Opps thats the window a little opened

[goots]

The only reason I would have the window a little is the choc.lab. could a little air she to sit on the sofa went we travel and its not to hot to have the A/C on...

[TucsonJim]

Harvard wrote:
The open window may cause the water traps in the sinks and shower to burp foul odours.

I'd sure like to understand the scientific reasoning behind this comment.
:R