[Archived]

Joel,

I posted that and after your post on that thread I looked at my coach and my evaporator bay door and the outside air vent cap is not like yours so a picture will not help.

My previous vintage coach has a small vent in the evaporator bay door. Behind that vent is a panel or cap on the evaporator ducting that when removed allows outside air to enter the coach. Going by memory I think if you remove that cap you also have to open a flapper just inside the ducting so the path for fresh outside air is open.

If I am making sense anyone that has a late 90’s vintage coach should have the same set up and posting a photo would help.

Sorry Gil, this only applies to real OTR. (I couldn’t help myself saying that.)

[Greg]

So you’re saying the vent in the door and the hose are to admit fresh air into the system and are normally closed.

If I understand, the hose is blocked off by a plate and/or shutter at the vent (door) end of the hose?

[tom]

I always kept my real OTR air intake closed and sealed. This way, I was always recycling the interior air as much possible. In this manner, the coach cooled down REAL fast……and stayed cold even when outside ambient temperatures were well into the triple digits. In fact, as the miles went by, the inside of the bus just kept getting colder and colder.

I even went to the trouble of sealing the gap at the flap control valve with duct tape.

Worked for me…

[Greg]

Yes, the vent should be blocked normally. The fact you have a hose means your 99 is different tan my 97 and my 06. Go figure.

As Paul points out blocking the intake vent recirculates the air. Opening the intake brings in fresh air which would be OK except with diesel odors and dust and dirt off the highway that would get the inside of the coach pretty dirty. But for pressurizing the coach temporarily opening the flow path is an easy way to do it.

[AL]

Thx; I’ll take another look tomorrow AM.

[Gerald]

Give us a picture if you can Joel…

[Jim]

On my coach, the vent in the door is connected to a 6″ flexible duct hose which goes to an inlet on the evaporator housing located above the evaporator. Inside the inlet is a movable flap connected to a handle on the outside of the inlet to change the position of the flap. The flap itself, when closed, does not completely seal off outside air as there is a gap around the outside of the flap. I’m actually purchasing 2 6″ hose caps to attach instead of the hose to prevent any outside air intrusion.

My flap was in the closed position and my OTR performance has been fine. I opened the valve, closed up the coach and turned on the OTR with max fan speeds. It worked slicker ‘n snot! Found a stress crack at the left upper corner of my front cap.