2nd Air Conditioner - Montana Owners Club

dudleydo · 08-22-2009, 06:30 AM

Hi All,

My wife & I have just purchased our first RV, a Big Sky Model 340 RLQ which comes with the standard A/C in the livingroom area and are looking for advice on the need for the second. We plan the first year of use (2010) to park it in a campground for the season April to November on Cape Cod. We do like it cool when we sleep and hear different opinions on whether the single one will do the job.
We'd appreciate some feedback. Also, what should the second one cost and would you have the original dealer install it or are there better options?

Thank you for your help. Dudleydo

dsprik · 08-22-2009, 07:13 AM

Doug, welcome to the forum. There has been a ton of info on 2nd A/Cs. Try a search. I have a 2nd A/C, Low Profile Penguin (Dometic) 13.5K BTUs. I assume your Big Sky is "prepped" for a front A/C?

Glenn and Lorraine · 08-22-2009, 08:13 AM

Here are 2 recent threads discussing 2nd airs

#1

#2

sreigle · 08-22-2009, 12:08 PM

We fulltimed for almost six years with just one a/c unit and were fine. We found it did a very nice job until the outside temperature on a humid day climbed into the 90's or above. Then it struggled. Nights were fine, though. Our solution to the heat situation was to evacuate and head to cooler climes. Since we planned to spend this summer where it does get very hot and humid, we went ahead and installed the second a/c. We do not regret it.

However, in your shoes, I'd give it a go with the one and see if you find it's not meeting your needs. Then you could add a second a/c. That's basically what we did, anyhow.

harleyrider · 08-22-2009, 12:25 PM

I think always 2 is probably better then one,that being said I just closed on my house(I`am homeless)august 21.Camped out now at work until retirement date October 1.As luck would have it we are here in philly in a heat wave.Its been in the 90`s like 6 days in a row with pretty good humidty.I have only 1 AC.And to be honest its been ok in here.I set the termperature at 75 inside its been pleasent to be inside.Also the AC isn`t working 24/7 it does shut itself off for a spell.In fact getting out of the shower its darn chilly.So far i`am happy the way my one AC is working.

exav8tr · 08-22-2009, 01:08 PM

Having travelled two years in mine, I would not be without the second air. Having said that, the choice depends on your lifestyle. If you do a lot of sightseeing and are not in the trailer during the heat of the day, then probably one would be ok. When we are in a park with only 30 amp power we keep the shades down and make sure the trailer stays airtight during the day. Then we just run the bedroom Air at night and all is fine, of course, if you are in the trailer during the day, then you might think about adding the second. We got a 13,500 Dometic Brisk Air from CW and have had no problems with it at all. I think we paid around $650 installed. As fulltimers, and having bought our trailer in Alaska, we use CW alot because we can get service just about anywhere in the US, plus the warranty coverage is available at any CW. Another factor is where you will be camping, of course. We have camped from Tucson, AZ to Mass, now, and enjoy our creature comforts like a cool dehumidified trailer during the day. BTW: IF YOU LIKE TO SLEEP IN THE COOL AT NIGHT, I HIGHLY RECOMMEND THE SECOND AIR..I hope this clears things up for you!!!!!

rames14 · 08-22-2009, 01:21 PM

We just got our second Montana - a 2010 Big Sky 365. We ordered it with second A/C because we found exactly what Exav8tr did - if it gets above the 90's it can get hot. I think our old unit would pull the temp down about 15 degrees. So, when it got to 100 it was about 85 in the Montana. Can you get by without it - yes. Are there times you might wish you had it - maybe. All depends on where you plan on camping and for how long. Enjoy your new Big Sky.

H. John Kohl · 08-22-2009, 01:52 PM

I have two ACs and concur with the 90 degree issue. With the new ducting to both ACs you can run the AC that is farthest from where you are sitting or sleeping and reduce the noise level in that area. Then of course you have the second one when needed. We like to use two when first setting up to cool Monty down quicker.
Cheers,

TLightning · 08-22-2009, 01:59 PM

Depends where you are going...at the Cape one should be fine. We started with one, then headed south in July...and put in the second.

HughM · 08-22-2009, 02:24 PM

We have found that at 32ft that's the limit for one A/C when the temps are in the 90's. We are now in a 35ft and had a second air added and would never go back to one air unless we purchased a rv under 32ft. If you stay in the northern part of the states you should be OK. However if you come south in the summer you'll be glad to have that second air especially if you have no shade.
Hugh

adelmoll · 08-22-2009, 03:19 PM

We fulltimed for 4 years in our Montana with only one air conditioner... We now have the new Big Sky and ordered it with one air conditioner... Because we bought a lot in Florida and are spending more and more time there, we will probably add a second one when we feel we need it but in Cape Cod we sure didn't need it... As to when and where you add it, I don't think it makes a lot of difference... Just find a reputable dealer. It is not that hard since it is already wired for the second one... As to the cost, that's a good guess. The 2010 Big Sky lists it for $695.00. I don't think they will change that much if you wait awhile to find out what you need.

Helen

RRman · 08-22-2009, 04:21 PM

I survived almost a year in Slidell LA, even over the summer with just the one ducted AC. I did have to "insulate' the various ceiling vents and cover two of the (3) west facing windows to make it tolerable. The Ceiling Fan was always helpful and the AC would run nearly continuously in the afternoon and evening...What kept me from justifying adding a Bedroom AC is that with the ducted AC, the bedroom was always cooler and comfortable enough that I even had a fan in the bedroom to push cold air back into the main living area. So it just didn't make sense to make the bedroom even cooler...

kerry · 08-23-2009, 04:27 PM

Not to change the subject but will 2 Honda 2000's in parallel run 2 AC unit at the same time? Kerry

dsprik · 08-23-2009, 05:00 PM

No.

I have a 3000 Kipor and it will run either one of my A/Cs and a TV or so, but two A/Cs will over whelm it. I read somewhere here on the MOC that 2 - 2000 Hondas in parallel will put out about 3500 or a little less watts. Not sure why that was.

Maybe you can get away with a 15K and a 13.5K A/C (with absolutely nothing else trickling off you rig's 110) with your setup at the same time - I've never tried this combo. But I am skeptical. Maybe someone else here can be more specific?

KTManiac · 08-23-2009, 05:35 PM

Quote:

quote:Originally posted by kerry

Not to change the subject but will 2 Honda 2000's in parallel run 2 AC unit at the same time? Kerry

Definitely not. The two 2000's only make 26.3 amps rated, and 33.3 amps peak.

It is well known that while hooked up to a 30 amp service, you can only run one air conditioner. You need to be on a 50 amp service to run both at the same time.

You would need twin 3000's (46.6 rated/50.0 peak), or a 6500 (45.8 rated/54.1 peak) to run both air conditioners.

hookman · 08-23-2009, 06:17 PM

We put in the second a/c after the first summer. We use it when we have people in it cuts down the noise. Also when some people stay over they get cold at night so we just run our bedroom a/c. On real hot days it helps keep the unit cooler then with 1 a/c. We wouldn't be with out the second a/c.

sreigle · 08-24-2009, 09:48 AM

Quote:

quote:Originally posted by RRman

I survived almost a year in Slidell LA, even over the summer with just the one ducted AC. I did have to "insulate' the various ceiling vents and cover two of the (3) west facing windows to make it tolerable. The Ceiling Fan was always helpful and the AC would run nearly continuously in the afternoon and evening...What kept me from justifying adding a Bedroom AC is that with the ducted AC, the bedroom was always cooler and comfortable enough that I even had a fan in the bedroom to push cold air back into the main living area. So it just didn't make sense to make the bedroom even cooler...

Chas, I don't know you want to do this but it would eliminate the need for the fan to push the cool air back down the stairs. We replaced all our ceiling duct vents with the 360 degree style like our Jayco Eagle had. We got them at a Jayco dealer but I see our Montana dealer has them also. Perhaps another brand he sells uses them. It cost us five bucks per vent and just a couple minutes labor per vent. These vents rotate to open and close the vent to regulate how much air gets out of that vent. You could shut those down during the day and open them a little at night. It's hard to explain so here's a picture. The other benefit to this is we no longer have hot and cold spots. The cooling is even throughout, once we got each vent adjusted the way we want.

KathyandDave · 08-24-2009, 01:41 PM

Being Monty newbies, this last heat wave was the first test of our single A/C unit. As mentioned, it's fine up to 90 degrees. One experiment was to set the fan on LOW or MED, instead of AUTO. This kept the air moving nicely and wasn't too loud. Every once in a while, we'd hear the compressor kick in. Based on this experience, I'll be thinking about the second A/C if we spend significant time in hot places. btw, I really like Steve Reigle's vents.

dsprik · 08-24-2009, 02:00 PM

Quote:

quote:Originally posted by KathyandDave

btw, I really like Steve Reigle's vents.

I think Steve just glues some of those on to impress people...

Sorry, I was looking at his sig pic...

Red939 · 08-24-2009, 02:04 PM

Add the ceiling fan if you don't have one, then try it with just one A/C. If it gets too hot, you can always add the second.

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