Ken those ducts that are taped shut are the inlet for fresh air for the dash blowers. I too have them sealed up. In any season it lets the wrong temp air in.
Ken those ducts that are taped shut are the inlet for fresh air for the dash blowers. I too have them sealed up. In any season it lets the wrong temp air in.
Last edited by Joe Cannarozzi; 06-27-2009 at 02:18 AM.
Senior Member
Both my coaches had OTR, the first did not have shutters and the slots which admitted air to the Cruise Airs behind the bumper also let cold air spill into the driver's area. The current coach has shutters which default to the open position. When driving in cold temps, if I shut the shutters there is a significant reduction of cold air blowing across my legs.
I am sure all converters with Cruise Airs behind the bumper have air openings, but I don't know how many have shutters or a way to control air flow.
What I am curious about is how many with roof airs have no openings to the storage area behind the front bumper, and of those that have no openings, do they feel heat or cold blowing in from outside at the driver's area? I don't think Prevost intended for that area to receive outside air flow so once air gets into that area it finds its way into the dirver's area.
Senior Member
On mine, if the OAT is nice and I want fresh air only, opening the shutters makes a big difference in the amount of airflow to the vents. It's not enough of a flow to get air through the vents without the use of the blower, but it is a signficant improvment on volume.
Jon - Don't quite understand why your shutters would default to open while driving with OTR? I think most are opposite, including mine. Sure helps keep the road crap out of the compartment.
Paul - Not to drag out the OTR/Cruiseair debate, but if I have to run a couple cruiseairs while driving, I still have the full use of the dash air (which is working very well) and that may make the difference between roasting or not as you stated. All of this is providing the cruiseairs are running and not overheated of course.
Senior Member
I would think the biggest problem with OTR failure for the driver is lack of dash air. I could see it warming up quickly in that situation - even if the cruiseairs are working.Originally Posted by truk4u
Senior Member
With our OTR air coach there is a rocker switch labeled AC or Heat. In the heat possition is the heat supplied by hot water heat from the engine solely or does the OTR compressor engage and supply heat from a heat pump mode?
Dumb question I know but I've never thought to check it out when I'm at the coach.
Harry
Shirley & Harry / 2000 Liberty / 2008 GMC Envoy Denali
No Harry it is not a heat pump.
I know you will probably not need this info but for those who do need the heater if you still select a/c and then turn just the thermostat to warm the cabin the windows will defog much better verses going to the heat side of the selector.
Senior Member
Tom......I have no idea why on my coach and likely others of the vintage our shutters default to open. If I were to guess I would say to keep people from forgetting to open them when they run the Cruise Airs. I think Paul's coach has it right. They default to open and close when the ignition is on.
On OTR equipped coaches, at least on our 87, our 97 and apparently Harry's newer coach the system uses heated engine coolant to moderate the temps. If I set my thermostat to a cold position to cool the coach rapidly the heated engine coolant solenoid valve stays shut and air blowing across the evaporator coils of the AC is not heated at all. Once the coach starts to get cool and we want the temps inside the coach a little warmer, but still air conditioned we will see the "heat" annunciator light come on from time to time telling us the solenoid valve is opening letting coolant through the heat exchanger to warm up the cool air conditioned air a little before it blows into the coach.
The OTR AC system is powerful and it will have you wearing winter clothes unless you mix a little of the air conditioned air flow with some air heated up for that purpose. On newer model coaches I am not sure there is an indicator light to inform the driver that the air flow temps are being adjusted.
You have just described ours ,on our 85 chassis, to a tee.
When the heat light comes on you know your chillin
Senior Member
Had a quick look at my shutters = Open when the ignition is off and closes when coach is running and air is up.
Makes complete sense for a coach with OTR. I suppose mounting some sort of screen to keep the road toads out would defeat the purpose. Reduction of air flow by 50% by placing a screen.
Senior Member
On mine (no OTR A/C) the shutters come on automatically by some relay. They will even open and close while stopped ( key off). You can be sitting in the coach and hear them open and then close then open and close. No idea why.
GregM
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