Another Air Conditioner Question

[jdjones]

We have a 2014 Sprinter 324FWBHS that only comes with one air conditioner in the living room (which is in the middle of camper) and is wired for a second unit in the front bedroom. My question is how will adding the second unit help cool the bedroom in the back where it is extremely hot. We went through the camper and made sure all the duct work that we could reach was sealed tight and that helped a little but it is still uncomfortably hot during the afternoon. When they install the second unit do they close off the ductwork to the front bedroom so that more cool air goes to the back of the camper?

[therink]

I am not sure where you live/camp but if the rig is in full sun in 80 plus Temps it will be tough to keep the rig cool. I Park my 340 fiver ( a little bigger than yours) at a partially shaded site and my one 15k but AC keeps it comfortable.
One thing I did on mine was close off the main ceiling duct behind the last rear and forward vents (using rags and foil tape). This increased air flow to those vents noticeably. I also partially closed off vents where air was coming out to fast. This Sent more air flow to the very to that needed it (front and rear). Each rig is different. I would play around a little bit to make sure the air flow on tthe AC you have is maximized.
Also try removing the inside cover (4 or 5 screws) and makes sure the plenum is sealed between supply and return side. Also while in there, make sure foil tape is neat and smooth and no openings into ceiling cavity except that for where the fire and aft ducts go out. I had to complete redo the sloppy job done at the factory. All these things help maximize efficiency and flow.
I hope this helps.

[bobbecky]

Almost doubling the A/C tonnage will cool the entire rig. We can keep our rig quite comfortable with the 15K in the rear and the 13.5K in the front, even on the 100+ degree days. The biggest thing you can do, is turn the units on early, before the rig gets heated up.

[jdjones]

Thank you for your responses. We camp mostly in TN....hot summers with high humidity. We have lots of kids in and out of the camper and I think just one air conditioner isn't going to cut it. We have resorted to using a portable air conditioner in the back bedroom and it helps somewhat but takes up too much valuable space when using and when storing. I just needed a little reinforcement when pleading my case to my husband for a second unit :D

[Kristi]

. I just needed a little reinforcement when pleading my case to my husband for a second unit :D

We added a bedroom A/C to ours and it was worth every penny!

[shane772]

I've got the same setup you're wanting. I close off the vent in the front bedroom when running both of them. We also use the foil bubble type insulation in the windows during the summer.

[sourdough]

Check the duct work, adjust the ducts for airflow.....AFTER you buy that 2nd AC. You will find that it is going to be one of the best decisions you can make.

[PARAPTOR]

Was not sure which thread to put my questions in so I will try this one. Have been surviving with a single 15k the last few weeks in upper 90's by playing with the vents, cool drop vents on the unit and fans. Basically making in work. So here are some of my questions:

What are the differences size wise of a ducted versus a non ducted unit. Can not seem to find a picture of a ducted unit versus non ducted??

I assume if your rig is prepped for a second unit that either type will fit. Although read a post that Keystone said a ducted AC could not be used on his Raptor? Reason??

Have not looked into the ceiling, what does the duct work look like rectangular metal from central unit and then individual register into that OR are there individual flex ducts from the main unit to each register??

Here is my dilemma I currently have a ducted 15K feeding registers in all areas (Garage, Central Area, Hall Way , Bathroom, and bedroom). Adding say a non ducted 13.5 just to blow into the bedroom seems like an over kill in that area.

What I think would be idea is to add another ducted unit 13.5 OR 15K in that prewired bedroom area and redo the registers. For example bedroom unit feeds duct to bedroom, bathroom, hallway. Existing 15K feeding central living area and Garage. I think this would be ideal and make best use of two units.


What Am I missing, can this be done? Can someone point me in the direction how these ducts are run and difference in ducted versus non ducted units.

Would like help finding information. THANKS

Going somewhere where it is cool and has food:D

[jsmith948]

Just an added thought/suggestion. Recently, our sticks & bricks a/c unit died.
We had already scheduled a replacement, but, the old unit died several days too soon. We moved out to the trailer - the temps were in the high 90s - full sun.
The 13,500 Coleman-Mack did o.k., but, it was still getting pretty warm. We placed foil backed bubble insulation from Lowe's in all of the south and west facing windows. Huge difference. Just cut it to fit and placed it between the shade and the window. After that, the a/c kept the trailer nice and cool. Unit cycled also. FWIW:)

[JRTJH]

I would hesitate to divide the ductwork. If you do, then on all but the most comfortable nights you'll need to run both A/C's to evenly cool the trailer.

If you're going to go that far, why not modify the ductwork so you can run one, both or either of the A/C's and have cool air delivered to all the vents.

Many of the "dual ducted RV's" give the owner the option of running the front unit when in the back of the trailer and the back unit when sleeping in the front. Much less noise and a more comfortable movie night that way.

ADDED: If you go here, you'll see the "racetrack concept" that Keystone used in the Laredo RV line. http://www.keystonerv.com/media/894566/laredo20x30tableposter_apr14.pdf

Essentially it involves a "common central duct system" with an independent air conditioner on each end of the "racetrack"...

Here is a thread on another forum discussing one of our member's issues with installing his air conditioner "properly" after determining that the factory had not completed the installation. http://forums.motorhome.com/index.cfm/fuseaction/thread/tid/27925056/print/true.cfm

[jtyphoid]

Was not sure which thread to put my questions in so I will try this one. Have been surviving with a single 15k the last few weeks in upper 90's by playing with the vents, cool drop vents on the unit and fans. Basically making in work. So here are some of my questions:

What are the differences size wise of a ducted versus a non ducted unit. Can not seem to find a picture of a ducted unit versus non ducted??

I assume if your rig is prepped for a second unit that either type will fit. Although read a post that Keystone said a ducted AC could not be used on his Raptor? Reason?

I believe that ducted and non ducted are the same above the roof. The differences are the plenum and cover that install from the inside of the RV.

A ducted unit would not work, or at least would not be the best choice, where there isn't a duct to tie into.

[chuckster57]

Ducted will require a "dual zone" thermostat to operate, non ducted will have the controls on the unit.

[1jeep]

Ok, I have a carbon 327 with dual ac units, the 2nd in the bedroom. they are both ducted and I have a dual zone thermostat. My question is I have a reservation at a campsite that only has 20amp service, I know I cant run both AC units. will running the one main unit cool the bedroom as well as the main cabin? Is the duct work all connected to each other? My other option would be to run the generator so I could cool down the trailer then run just the one at night off the shore power.

[PARAPTOR]

Just looked over at the monitor As far as I tell only AC is running and drawing 17 amps from that phase. Probably can run one Ac and not much or anything with it. Have heard people run AC off their home 20 amp circuit with no problem. Make sure the cord you use is at least 12 gauge

[1jeep]

Just looked over at the monitor As far as I tell only AC is running and drawing 17 amps from that phase. Probably can run one Ac and not much or anything with it. Have heard people run AC off their home 20 amp circuit with no problem. Make sure the cord you use is at least 12 gauge

I know I can run one unit and I also know the second will trip the breaker. I didn't know if the main unit would push air to the front vents or are those bedroom vents only connected the bedroom ac unit?

[KSH]

I've run the AC off a 20amp circuit at the house before while cleaning it, no problems.

Sent from my SM-G900T using Tapatalk

[Festus2]

While it may be possible to run your A/C using a 20A circuit, don't forget that you may run into difficulty if you start using the microwave, hot water tank (on electricity) or any other higher-amp items - coffee pots, hair dryers, etc. at the same time. By the time the A/C "gets what it needs" from 20A, there isn't much left over.

[1jeep]

Both units? I know one will run, but will it be enough to cool the trailer in 80 degree weather.

My real question wasn't will it run or if I can run both units, because I know both wont run on a 20amp circuit. But will running just one unit be enough to cool the bedroom.

BTW...my previous 32' outback ran no problem on a 20 amp, but it only had one unit and that did a fair job of cooling the trailer. My new trailer has a bedroom that is really separated form the main trailer.

[Kristi]

Both units? I know one will run, but will it be enough to cool the trailer in 80 degree weather.

My real question wasn't will it run or if I can run both units, because I know both wont run on a 20amp circuit. But will running just one unit be enough to cool the bedroom.

BTW...my previous 32' outback ran no problem on a 20 amp, but it only had one unit and that did a fair job of cooling the trailer. My new trailer has a bedroom that is really separated form the main trailer.

We have a ducted a/c in the main cabin and a non ducted in the bedroom. What we have done in the past if we were at a 30 amp site rather then 50 amp is run the main a/c during the day then turn it off and run the bedroom a/c at night to sleep. This may work with your dual areas, not ideal but the best I could think of. :) Another thing we do when going on short trips is turn the a/c on at the house a couple days in advance so the inside of the trailer isn't like an oven when we get there.

[1jeep]

thanks for the suggestions, I guess I can investigate this by turning on the main unit and seeing if I get air coming out if the vents in the bedroom.

[travelingnurse]

I have a Montana high country. It only had one A/C and I could not keep it cool at all in 85+ temps. Last week I installed a 13.5 Btu in the bedroom and I am 100% satisfied with the add on. It was the best 800$$ i spent. I bought a dometic. I installed it myself in about 2 hr, it was quite easy if your a handy person. Now my whole camper stays cool and comfy. I full time on a hospital parking lot in direct sun on an asphalt desert. The second AC is just worth it.

[Povo]

I know I'm coming into the middle of this and don't want to redirect the thread, but this seeems like a good place for my question.

We are out for this 4th of July in Central Oregon and we are in the middle of a heat way (pushing 100 degrees). While this isn't the norm, it is making think about a 2nd AC unit. We plan on having this a long time so it seems like it may be worth the investment. So, how can I tell if my 327RES is wired for a 2nd unit? If it is, would it just add more air to the existing vents throughout the cabin? And would it use the same controls (one control that controls both units simultaneously) or would there be two controls.

Basically, in simple terms, what's involved in adding a second unit? Any ideas about cost?

[therink]

I know I'm coming into the middle of this and don't want to redirect the thread, but this seeems like a good place for my question.

We are out for this 4th of July in Central Oregon and we are in the middle of a heat way (pushing 100 degrees). While this isn't the norm, it is making think about a 2nd AC unit. We plan on having this a long time so it seems like it may be worth the investment. So, how can I tell if my 327RES is wired for a 2nd unit? If it is, would it just add more air to the existing vents throughout the cabin? And would it use the same controls (one control that controls both units simultaneously) or would there be two controls.

Basically, in simple terms, what's involved in adding a second unit? Any ideas about cost?

3 things to check:

1) Is your rig 50amp?
2) if so, there should be a circuit breaker labeled 2nd AC
3) If both are confirmed, there should be a Junction box with a blank cover on ceiling in front bedroom near roof vent.

If so, that is where you would wire the 2nd AC into. Keep in mind that running both ACs at one time would require 50 amp shire power.

[Povo]

Yep on all - 50 amp, circuit breaker labelled 2nd AC, & junction box in bedroom. So installation shouldn't be an issue (for someone who know what their doing).

[JRTJH]

Povo,

It's not really that difficult to install an air conditioner as long as the vent is cut in the roof and the wiring is installed next to the vent. The biggest "hurdle" is getting the unit onto the roof. After that, it's really not difficult at all.

Here is a link to the installation instructions. Look them over and see if you believe it is within your "level of experience" and your "physical capacity" if it is, you can save yourself $300 to $500 bucks with a "do-it-yourself" job.

http://www2.dometic.com/1f24ead8-6316-41b6-894c-d01f87ce6bad.fodoc

Usually, for someone who has never installed an air conditioner, the time from start to finish (actual work, not chilling beverages for after the job) is about 2 hours.

Good Luck

[Sniper]

As a newbie to RVing, how can I tell if my 2008 Raptor is pre-wired for a second AC unit?

[chuckster57]

As a newbie to RVing, how can I tell if my 2008 Raptor is pre-wired for a second AC unit?
If your unit is 30A service, it WON’T be prewired for 2nd A/C.
If your unit is 50A service, then look at the ceiling where your trying to put the second unit. If there is a junction box cover then odds are it’s for the second unit. You can also remove the Garnish ring, and look for then110 wiring. The “garnish ring” is the trim ring that is screwed to the ceiling.

[TYHLR]

Not to hijack this thread but am having problems with my dual A/Cs. When only on the genset I can't run both A/Cs. Don't yet know about shore power. My genset is 50 amps. The generator will power either a/c but not both. When I attempted both, it tripped the breaker on the genset. As the camper was heat soaked (over 90 degrees) should I have let the main one run first to cool down the coach before turning on the bedroom A/C? Any suggestions appreciated.

[5J's]

How old is your gen? How many hours on it? I'd lean towards a tired gen?

[TYHLR]

The genset is what was installed at the factory in 09. Currently has 720 hours.

[5J's]

Ok, you said it would run either AC but not both. I'm assuming that you've tried both indivually. The next think I'd look at is a possible weak genny breaker. If you've got access to an amp clamp you could verify the current draw of each unit at your breaker/fuse box. If the units are the same size and make the current draw should be fairly close. If not this could indicate a possible AC issue.

[mazboy]

some told a trick. start with your bedroom a/c, turn temp to 60 degrees. than after it is running turn your front a/c on.

trick is the bedroom a/c will never get to 60 so the a/c will never recycle.

[TYHLR]

Thanks for the responses.

I saw on a different forum some chatter about both A/Cs being on the same electrical leg of the genset thereby overpowering the circuit/breaker. It is pretty clear that both of my A/Cs are on the same leg as when it popped the genset breaker, both A/Cs stopped running while the remainder of the coach had power.

Am considering an attempt to discover how to move one of the A/Cs to a different power leg from the genset.

Has anyone attempted this before or if it can be done? Seems like moving the A/C breakers within the panel to put them on separate circuits may do the trick.

[TYHLR]

Thought that i would share my fix for my AC problem. My genset is a 50 amp capacity with one breaker providing 20 amps and the second breaker providing 30 amps.

I discovered that both of my ACs were on the 20 amp circuit. I simply pulled the breaker box from the genset, swapped the wires on the 20 and 30 amp breaker. Problem solved.

[5J's]

Thought that i would share my fix for my AC problem. My genset is a 50 amp capacity with one breaker providing 20 amps and the second breaker providing 30 amps.

I discovered that both of my ACs were on the 20 amp circuit. I simply pulled the breaker box from the genset, swapped the wires on the 20 and 30 amp breaker. Problem solved.I hope you checked the wire size. 12ga wire isn't rated for 30 amps.

[TYHLR]

I did. Was trained as an electrician as a young man. It was clear that the wires were placed on the wrong breaker when manufactured.

Cheers.

[5J's]

Good find!