When the Coleman Mach A/C in my class C is running in the cool high/low position does it pull outside air into the coach, or does it circulate the air. Also when in the fan position does it pull in outside Air? I'm asking because we are going to riding and camping in the 4 corners area and there could be smoke from the forest fires north of there. My owners manual wasn't much help. It's a Coleman Mach 3 #48253c966.

Your AC should not be pulling in any outside air just recirculating the air inside the trailer.

Actually RV air conditioners, at least all I have seen bring in air from outside suck it across the coils and dump cold air inside.

Boon Docker wrote:Your AC should not be pulling in any outside air just recirculating the air inside the trailer.x2

Ok.. So the diagram shows the air is being pulled from inside the coach then cooled. So am I right to assume when it is in the fan operation the only difference is that the air does not get cooled? It is just circulated.. I tried looking all over the internet for an owners manual for this unit, but only found installation instruction.

Air Conditioner question | Good Sam Community

Boon_Docker
Explorer III
Jun 14, 2018
Your AC should not be pulling in any outside air just recirculating the air inside the trailer.
donn0128
Explorer II
Jun 14, 2018
Actually RV air conditioners, at least all I have seen bring in air from outside suck it across the coils and dump cold air inside.
Boon_Docker
Explorer III
Jun 14, 2018
ksg5000
Explorer
Jun 14, 2018
Boon Docker wrote:
Your AC should not be pulling in any outside air just recirculating the air inside the trailer.

x2
docsouce
Explorer II
Jun 14, 2018
Ok.. So the diagram shows the air is being pulled from inside the coach then cooled. So am I right to assume when it is in the fan operation the only difference is that the air does not get cooled? It is just circulated.. I tried looking all over the internet for an owners manual for this unit, but only found installation instruction.
Boon_Docker
Explorer III
Jun 14, 2018
docsouce wrote:
Ok.. So the diagram shows the air is being pulled from inside the coach then cooled. So am I right to assume when it is in the fan operation the only difference is that the air does not get cooled? It is just circulated.. I tried looking all over the internet for an owners manual for this unit, but only found installation instruction.

Yes, you have assumed correctly.
j-d
Explorer II
Jun 14, 2018
Doc, Your conclusions are correct. Some room A/C window units have a little passage that can be opened to bring in some outside air. We had an old Coleman Mach RV A/C that I thought had something like that, but it's been a long time so don't hold me to it. Our newer Mach does NOT.

BTW, that diagram is what you need to understand to periodically clean your Roof A/C. It's pictured without the plastic shroud. The angled shrouding over the Blue Part (evaporator) has to come off in order to clean the blue coil, and the drain pan and drain outlets directly under the blue coil. The red coil (condenser) may trap a few leaves but that's usually it. Notice, the air blows through from the front side of that coil.
Boon_Docker
Explorer III
Jun 14, 2018
Also clean the inside filter once in a while.
docsouce
Explorer II
Jun 14, 2018
I appreciate the information. The folks on RV.NET come through again!!
wolfe10
Explorer
Jun 14, 2018
donn0128 wrote:
Actually RV air conditioners, at least all I have seen bring in air from outside suck it across the coils and dump cold air inside.

Let's clarify.

Air from the INTERIOR goes through the EVAPORATOR and back to the INTERIOR (no outside air).

As with 100% of A/C's, the CONDENSER takes outside air and returns it (warmer, no doubt) to the OUTSIDE.