'98 Mountain Aire Air Condition noise

artrosch · 08-13-2009, 11:13 AM

We've had our gasser 98 Mt. Aire for five years, and it's been solid for us.
We live in the SF Bay Area, not much travel, mostly full time CGround hookup.
Seldom need AC. BUT...we've moved to a cheaper, nicer, more friendly CG,
its only drawback is very little shade. We're going to need AC a lot more.
This Newmar has an in-house AC design. There's no air box. rather it has eight five inch vents running the length of the coach. I guess intake/output.There are two Duotherm Penguins low profile atop our rig. All controlled by a four button thermostat that is recently refurbed and working fine. The front duotherm has never worked, but we didn't need it. Now, the major problem is noise! GAWD, our rear unit roars, and it hums, whoo whoo whoo. Impossible. We can stand it for ten minutes. I've done a lot of insulating, bought several rolls of reflectix, covered the windshield, the slide out, laid a four foot segment at the top front where it catches the most sun. I investigated the front duotherm and found a yellow lead from the motor (it's the one attaches to T2 in the wiring diagram) has come unsoldered. That would prevent the unit from working! I'm hoping when I get it reconnected, we will have service from the front. Maybe....Does anyone know how to quiet these monsters? Is there a way to pad underneath the duotherm in the attic to give us a little peace?
Everyone says they're noisy. We're at the point of considering a window unit.
Shared experiences, anyone? Insights? Solutions? Thanks.

Art

Jim Gibson · 08-13-2009, 11:45 AM

Art: My 1993 Mountainaire has the same thing,rear air very load front not quite so bad,also one vent blows cold air on the thermostat

artrosch · 08-13-2009, 12:38 PM

Jim, I'm not sure what you mean by one vent blows cold air on the t'stat. You mean one
zone, only? Is there a way to get the front to blow cold and leave the back one off?

thanks
art

Jim Gibson · 08-13-2009, 01:19 PM

Art: I mean that one of the a/c vents that blow cold air from the ceiling from the rear a/c blows on the t stat just inside the kitchen , I think the duct system is one continuous duct Jim

artrosch · 08-13-2009, 02:09 PM

Oh, I get it. Well, the tech just left. Our front duotherm's circuit board is totally fried.
It was like that before we bought the coach, just never needed to use it. We still
have a/C, with the rear unit. it's fairly effective if we can deal with the noise.

Art

**"007"** · 08-13-2009, 02:11 PM

Welcome to both of you to the Newmar forum and irv2.
The age of your coach's could mean that the foam seal under the AC units have dried out and may need replacement. A new one may cut down the noise through out roof area. The AC's may need some servicing by some AC tech who could lube your motor bearings and what ever else needs work. A Mobile tech could help if your setup in Campground.
For some reason back in 90's rear AC's were alway noisy I had one on my 98 which was serviced at Newmar and AC Tech was able to quite it down.
The vent near wall control should be turned so it vents away from control, with the front AC not yet working the rear AC is controlled by a small thermal control in bedroom that feeds back to main control in kitchen, it has a plastic cage about size of a quarter mounted on wall.
If there is anything else need to know just ask, enjoy the forums and do post often.

There is a zone control on main control with Mode select and yes the two ducts in ceiling cool & return travel in ceiling from front to rear of coach.
TOTAL COMFORT AIR

artrosch · 08-13-2009, 04:59 PM

This is great! By posting in forums I located a colleague who keeps some of the old
thermostats and boards, thus saving me a vast headache. And a lot of money.
Should anyone need a four button Comfort Control system or parts, let me know and
I'll link you. 007, your info is precious.

Art

artrosch · 08-13-2009, 07:09 PM

And, one more...will I be able to run ONLY the front a/c or are both units assigned to
Zone 2, and I'll have no choice but to endure? I note that the front does not have
the dip switches, so I have a feeling I know the answer to this question.

Art

BTW, come see my award winning photos at
www.artsdigitalphoto.com

especially if you like stars, Arches NP and stuff like that

**"007"** · 08-13-2009, 11:38 PM

If you had this control you select which ever AC you want front,rear or both.

artrosch · 08-14-2009, 12:40 AM

I have the four button version. I can assign zones to each utility. When the front A/C
circuit board is installed, then I might have the possibility of using whichever i want.
I guess I'll know when that repair is done. I thought maybe there was some design
factor that put all the a/c functions into zone two.

Art

**"007"** · 08-15-2009, 12:25 PM

Not that I'm aware of as you already have notice rear AC output can be felt up front the same holds true for front AC when both work together the result is more efficient cooling.

artrosch · 08-15-2009, 01:58 PM

Next week I should have both units functioning. It would be ideal to run both units
for greater cooling, but as we spend our movie/tv time in the bedroom it would be
great to run just the front, and get away from that dreadful noise. The back of the coach is in shade, fortunately, so it would work out okay, we could get pretty cool. A change of the rear gasket is somewhere in the future, but that's a job we'd have to go outside the cground. Oh yeah, here's another question. There's an old style Honeywell
thermostat just below the Comfort Control unit. Non digital, a little stub sticking outside the box to be hand-set on an engraved scale. Has anyone seen this? Is it some legacy
of an older furnace system before we came into the coach in 2005? This is a 98, fyi.

thx
art

PoetryJoe · 08-17-2009, 10:07 AM

Quote:

Originally Posted by artrosch

Next week I should have both units functioning. It would be ideal to run both units
for greater cooling, but as we spend our movie/tv time in the bedroom it would be
great to run just the front, and get away from that dreadful noise. The back of the coach is in shade, fortunately, so it would work out okay, we could get pretty cool. A change of the rear gasket is somewhere in the future, but that's a job we'd have to go outside the cground. Oh yeah, here's another question. There's an old style Honeywell
thermostat just below the Comfort Control unit. Non digital, a little stub sticking outside the box to be hand-set on an engraved scale. Has anyone seen this? Is it some legacy
of an older furnace system before we came into the coach in 2005? This is a 98, fyi.

thx
art

Yes, that older unit is for your fan in the kitchen.