Want to add 2nd AC unit

RickyB · 04-04-2018, 05:19 PM

Greetings. I have a 2012 Cougar fiver. Model is 323 MKS. When ever it's sunny all day & in upper 80's or more, it feels like we need 2nd ac unit. Just retired recently & will be where it's in mid 90's a lot.

The bedroom is in front and the ac is ducted to there. I guess 2nd unit would go there in bedroom. Would the second unit tie into existing duct or non-ducted unit. What size would go up front if non-ducted? Thank you for any help.

**sourdough** · 04-04-2018, 05:42 PM

I don't have a 5th wheel but my '14 319RLS is similar to yours in the rest of it. Our main ac is a 15k (I don't think you posted what yours is). I knew from previous experience that a trailer that size would need two ACs in the places we like to go when I bought it.

The main AC is ducted. It was prepped for a 2nd AC but not for the ducting as far as I knew. I had them install a 13.5k Dometic Penguin II in the bedroom ($39 install promotion by CW). At the front of the trailer, I chose the profile of the Penguin in the hope that it would cut some wind resistance.

The 15k does OK alone until we hit 90 or so in open sun (black sides on all sides) - and we like to sleep cold. With the 2 ACs we do fine. The one thing I don't like about the 2nd AC is that although the compressor cycles off and on, the fan never stops running. Unlike the 15k that starts and stops, the constant fan seems to really draw in the humidity when we are in FL. Next go round it will be 2 15ks, ducted and controlled so they don't just run all the time.

RickyB · 04-04-2018, 06:34 PM

I think main ac is 13.5k. Doesn't a 13.5k unducted upfront cause it to get very cold in bedroom with all 13.5k blowing out under unit? I would think that would cause it to cycle a lot.

**chuckster57** · 04-04-2018, 06:46 PM

It’s real easy to check for ducting. Take the inside garnish (trim) ring off. Then just look for aluminum tape covering the sides. If you see tape it is probably ducted.

RickyB · 04-04-2018, 07:27 PM

Thank you. I will do that when it hits 50°.

**sourdough** · 04-04-2018, 07:55 PM

Quote:

Originally Posted by RickyB

I think main ac is 13.5k. Doesn't a 13.5k unducted upfront cause it to get very cold in bedroom with all 13.5k blowing out under unit? I would think that would cause it to cycle a lot.

The AC can be controlled for temp and fan speed so you can set it where you feel comfortable - it has the "dump" opening at the bottom but you can close that and use the multiple vents on the side of the unit. Combined with the AC up front at a temp you like (main AC) the bedroom AC cycles very infrequently unless it is really hot - and we like to sleep cold as I said. Realize that an AC "unducted" was the way all trailers came back when and they worked well.....mostly.

Having an "unducted" AC is not a worry I would have.

RickyB · 04-05-2018, 06:31 AM

Thank you sourdough for your info.

RV6APilot · 04-09-2018, 09:23 AM

Ricky, as you know I recently replaced my old ducted 13.5 with a new 15K ducted
unit in our 318SAB 34' 5er. Yesterday here in Lakeland, FL it was 84 and the entire
unit was at 68 degrees. MORE than cooled the unit. Today it is supposed to hit 87
and we still are more than comfortable at 68. The bedroom duct is blowing more air
than the 13.5 unit ever did and the cold air... well let's just say it feel more like we
are camping in the upper Rockies than Florida.

RickyB · 04-09-2018, 09:42 AM

Gene, good for your success with cooling. I will have to make a decision this season. What surprises me is generally how inefficient the rv ac's are. When I compare the EER (energy efficiency ratios) with the window units, they are much more efficient. Maybe it will take some time for the expensive rv units to catch up with window units.

Frank G · 04-09-2018, 12:33 PM

Quote:

Originally Posted by RickyB

Gene, good for your success with cooling. I will have to make a decision this season. What surprises me is generally how inefficient the rv ac's are. When I compare the EER (energy efficiency ratios) with the window units, they are much more efficient. Maybe it will take some time for the expensive rv units to catch up with window units.

You would think they would be more efficient as many units they sell a year. I think the industry easily goes through 1M units. The gas fired furnaces are not any better, nor are the waterheaters.

As a rule if the unit did not come with a second A/C it wont have the ductwork. There are always exceptions. The wiring may also be an issue.

The quietness of the unit would be on the top of the list, they are not all created the same.

On a side note, we have 2 A/C units we set the Bedroom unit as primary in the day and switch to the Living room unit at night. Quiet! We live in our unit 6 month a year, in Florida under a big Oak tree.

RickyB · 04-09-2018, 01:21 PM

In one way I'm lucky Frank. There is an electric box next to the opening in ceiling hatch in our bedroom up front. There is also an unused breaker in panel on the other leg where ac is powered. So it should be a pretty easy way to go.

Carvendive · 04-09-2018, 01:33 PM

Is there such a thing? I thought they were all within a 15db range. Plus (for me) when sleeping, even low noise and cycling on and off can be annoying. I'd think constant running would be easier to sleep with. IMO. PS, I'm also installing one :-)

Frank G · 04-09-2018, 01:37 PM

Quote:

Originally Posted by RickyB

In one way I'm lucky Frank. There is an electric box next to the opening in ceiling hatch in our bedroom up front. There is also an unused breaker in panel on the other leg where ac is powered. So it should be a pretty easy way to go.

If you have 50A service and a free breaker you are on your way. Most (all) units can come with controls in the overhead so no external thermostat or wiring required.

RickyB · 04-09-2018, 04:09 PM

Yes it has 50a plug. I'm going to look for a high efficiency unit because there's no power where I store it. The more efficient, the happier my generator & gasoline can will be.

Frank G · 04-09-2018, 06:02 PM

I do not remember the brand of A/C unit in our last RV but the Coleman mach units in the Laredo are very tolerable. One of the reason we got rid of the last unit was the noisy A/C. Closing the vents on the A/C units and running through the duct system helps a lot to contain the fan noise.

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