OTR fresh air inlet?

While servicing the air filters on the OTR air conditioner, I noticed that there is what appears to be a flow regulator flap valve in the air inlet tube.

Is that, in fact, what it is? Kinda looks like the type of flow regulator found in home forced air systems, with a lever on the right side.

Is there a "normal" position for this flap? Looks like it could be "locked" into a stationary position. Or, is it supposed to be able to open/close freely?

Should it be "locked" in the open or closed position?

Comments/advice/observations would be appreciated :D

I not only keep ours in the closed position for summer use but additionally seal the gaps (quite large) around its edges with duct tape to ensure the best performance out of the OTR A/C. In the winter when that air is not as critical to the performance of the HVAC we open it slightly to allow some fresh air in.

This passage is allowing air to flow in and out of the bus weather the OTR is running or not. When we are stored or parked in the winter I open it all the way and it allows fresh air in and helps keep things from getting stale or musty.

Paul, would you please post a picture of the valve of which you are speaking.

Is it the one on the side of the bus?

JIM

Jim it is not a valve it is a damper and it is at the 3rd bay door drivers side behind that 8 by 5 opening in that bay door. The bay with the OTR evaporator and heater core.

It is the equivalent of recirculate or fresh air control on your car a/c but it is manual and is a far cry from being completely sealed up when closed.

I modified Jdubs coach to eliminate all outside air,I also modified my 08 coach by drilling out the pop rivets and installed a aluminum panel to inhibit outside air from entering the system.On a hot day with some outside air mixing with the bus air the bus air temperature will only be 60- 65 degrees with 100% recirculation the bus air will be 10 degrees colder.On a 100 degree day in the south I can maintain 72 or less in the coach with the bus air.

OK, got it. That's the opening Liberty recommends to be closed all the time.

Never mind the picture Paul. I just wasn't sure where and what you were talking about.

JIM

On mine, it appears to be controlled by an air-actuator type valve thingy (not manually). Are you saying this should be disconnected and flap closed/sealed? Also, I have a humidity control in that same bay that is set on +40. Any info on that gadget would be appreciated.

On ours we have an 1/8 inch gap all the way around the damper and with the vacuum created by the thrust of those two big blowers all kinds of humid outside air will be sucked in. The consensus is that any air that is allowed to leak in at this point will hurt the performance of the A/C and that is no good. Right ED?

A humidifier is usually only required in the winter I would turn it down or off in the summer.