Adding a 2nd AC unit

[mthompson]

I don't mean to high jack this thread...just wasn't sure where to ask this question.

I'd like to add a second AC unit (in the bedroom, first unit is in the rear in the Living room). There is already a vent above the bed and there is also a thermostat mounted (it might be for the fantastic fan) on the wall. Does that mean that the RV is already wired for it? How about the vent pipes in the ceiling, do I need to block it at some point to separate the front bedroom AC unit from the rear living room unit or leave them connected? Would everyone recommend a 15 K or do you think the 13.5 K is enough? Any idea on approx. cost to buy and have installed? What partticular brand does everyone recommend? The rear AC is a 15K Dometic.

Thanks in advance for your help and suggestions.

 

[gasman]

Mark, I would go with the 13,500 btu in the bedroom. It is wired for the 2nd a/c. Leave the duct work just as it is. We often will use the bedroom a/c in the evening to cool the whole trailer while we watch TV.

 

[Westwind]

I don't know if you haven't gotten this advise yet but do your research on brand, model etc. We have a low profile Penquin 13,500K, it pumps out alot of cold air which we have needed the past 4 days in Florida with temps pushing 90+, with both units going we have been able to keep it comfortable in the high 70's inside the fifth wheel.
Ours is extremely noisy, looking online they now have a Penquin II on the market and it looks like they might have made improvements which help quiet it down. We definitely would not be able to sleep in the bedroom with it going, but it does work well and allows us to shut off the living room AC while watching TV at night. If you expect to travel to warm area's I would definitely recommend a second AC.

 

[NewHopians]

Mark before getting smart and trading to a Heartland we put a second on my Montana High country and it was an Atwood brand. Rated at 13500 but had the capacity of 15000. It was really quiet and we were able to sleep in the bedroom. It came with a drop down screen and a remote control. It was a down draft as the bedroom was not ducted. Good luck with your decision.

 

[JJnVA]

Installed a low profile Coleman 13,500 last year in our BH. Easy to self install, hardest part was getting it up on the roof. Really like feature of fan staying on when unit comes up to temp & condenser shuts off, makes it less intrusive for sleeping. Much quieter than living room a/c. Adding the second a/c was best thing we have done as it assists the main a/c in cooling down the inside in less than an hour. As someone else mentioned, we also use the bedroom a/c to keep things cool in the evening while watching tv with main a/c off so we can hear!
Do not need to block off vents as they help circulate the air. Our 2011 BH 3610 bedroom crank-out vent when removed allowed access to the a/c power feed that was wired back to the circuit breaker panel. The Coleman model we purchased was for this type of installation on the roof thru the vent opening and was for non-ducted installation. The thermostat for the Coleman a/c along with fan only, high and low speed control were all included in the inside vent cover. When you buy a Coleman you have to buy the inside vent cover & controls as a separate item. We purchased our Coleman from an online vendor that we found thru Amazon. Be sure to shop around.

 

[Westwind]

Check out Atwood Air Command, my buddy put one in his 40' Holiday Ramble Presidential and it is so quiet and does a great job, he feels it doesn't put out as much cold air as his second unit which is a Brisk Air but agrees it is much quieter.

 

[mthompson]

Mark, I would go with the 13,500 btu in the bedroom. It is wired for the 2nd a/c. Leave the duct work just as it is. We often will use the bedroom a/c in the evening to cool the whole trailer while we watch TV.

Thank you for all of the replies, I'm sorry I haven't gotten back to anyone but we've been getting ready for closing on our home sale. We closed today (4/25/17) .....NOW, we're full timing it. Yahoo!!!!

I still don't know which way to go on the A/C. I contacted Heartland, gave them my VIN. # and they told me that my Big Horn is pre-wired and ducted front to back, so I'm not sure if I should get a ducted or non-ducted AC and then there's the question of the thermostat. Should it be a single unit or a

Multi Zone CCCII. Still looking for guidance.

Thanks, Mark​

 

[avvidclif]

A bigger unit is easier to turn down than getting a smaller unit and wishing for more. Since you're now fulltiming get the biggest, you visit Texas in the summer and you would be looking a for a third unit. Always go ducted, that way at night you can shut off the BR unit and run the LR, much quieter. Besides they never made a non-ducted that is a quiet as a ducted. If it's prewired for a second unit it should already (maybe) have a dual zone thermostat. Our last RV did and it had a sensor in the bedroom tied into the thermostat. We could set the bedroom and living room temperature different if we wanted from 1 thermostat.

 

[Gary521]

Even though your unit is ducted front to back, I do not think that you can connect the bedroom AC to the existing duct works. The wall thermostat is probably for a fantastic fan but hopefully it was wired for an AC. If it was wired just for the fan, you will not have enough wires to control an AC. In my former Bighorn, I had to run more wires from the wall thermostat to make it operable for the AC. If you cannot do this, I believe that there are models that have the thermostat in the remote control. Some have the thermostat in the AC unit itself. Pull the stat and check.

Most people get a low profile AC for the front unit to keep the overall height down.

 

[cookie]

I'm pretty sure that the 2012 Bighorn did not have the "ducted Whisper Quiet" system. There are ducts running front to rear but those are only tied in to the main AC unit.
Call Heartland once again and ask where the wires for the 2nd AC thermostat are located in the wall.

Peace
Dave

 

[Gary521]

All the AC systems are "ducted." You are confusing the newer "whisper Quiet" system with the older stuff. How else would AC air get to the front bedroom with the Unit over the living area?

 

[cookie]

All the AC systems are "ducted." You are confusing the newer "whisper Quiet" system with the older stuff. How else would AC air get to the front bedroom with the Unit over the living area?

You are correct, I forgot to add the Whisper Quiet to the ducted part.

Peace
Dave

 

[mthompson]

I'm pretty sure that the 2012 Bighorn did not have the "ducted Whisper Quiet" system. There are ducts running front to rear but those are only tied in to the main AC unit.
Call Heartland once again and ask where the wires for the 2nd AC thermostat are located in the wall.

Peace
Dave

All the AC systems are "ducted." You are confusing the newer "whisper Quiet" system with the older stuff. How else would AC air get to the front bedroom with the Unit over the living area? Gary521

You are correct, I forgot to add the Whisper Quiet to the ducted part.

Peace
Dave

Ok, so the plot thickens and I'm still confused. What is the difference between the "Whisper Quiet" and the "older stuff" ?

 

[danemayer]

I'm pretty sure that the 2012 Bighorn did not have the "ducted Whisper Quiet" system. There are ducts running front to rear but those are only tied in to the main AC unit.
Call Heartland once again and ask where the wires for the 2nd AC thermostat are located in the wall.

Peace
Dave

All the AC systems are "ducted." You are confusing the newer "whisper Quiet" system with the older stuff. How else would AC air get to the front bedroom with the Unit over the living area? Gary521




Ok, so the plot thickens and I'm still confused. What is the difference between the "Whisper Quiet" and the "older stuff" ?

On the older builds, the living room A/C unit pushed air through 2 ducts that run the length of the coach. That includes the bedroom. The air return is right under the A/C unit. The bedroom unit is not ducted.

On the Whisper Quiet, one duct is for outflow and the other duct is for air return. I think the A/C units are different as well, sitting higher for noise reduction. The bedroom unit is connected to both the outflow and return ducts. And the the overall duct and A/C design is such that the units work together rather than fight each other.

 

[mthompson]

On the older builds, the living room A/C unit pushed air through 2 ducts that run the length of the coach. That includes the bedroom. The air return is right under the A/C unit. The bedroom unit is not ducted.

On the Whisper Quiet, one duct is for outflow and the other duct is for air return. I think the A/C units are different as well, sitting higher for noise reduction. The bedroom unit is connected to both the outflow and return ducts. And the the overall duct and A/C design is such that the units work together rather than fight each other.

LOL,OK, I think I'm closing in on this. In the bedroom, there are 2 vents on either side of the room both are blowing air when the ac is on, so this tells me based on what you guys have said, that my system is the old type of ducted ac. But I should buy a NON-ducted ac unit since the new ac wouldn't tie into the ducts that are there, and it should just blow straight down into the bedroom.That being said, then the controls and the thermostat could just be on the face of the ceiling fixture, making the need for a separate thermostat useless. Am I understanding what's been said or am I still off base?

Thanks, Mark

 

[danemayer]

LOL,OK, I think I'm closing in on this. In the bedroom, there are 2 vents on either side of the room both are blowing air when the ac is on, so this tells me based on what you guys have said, that my system is the old type of ducted ac. But I should buy a NON-ducted ac unit since the new ac wouldn't tie into the ducts that are there, and it should just blow straight down into the bedroom.That being said, then the controls and the thermostat could just be on the face of the ceiling fixture, making the need for a separate thermostat useless. Am I understanding what's been said or am I still off base?

Thanks, Mark

You got it Mark.

Although we have a wall thermostat for the bedroom non-ducted A/C unit, when we need the bedroom unit running, I usually set the thermostat to something like 64 so it runs continuously. So I'm not sure the wall mounted thermostat provides any advantage over controls on the A/C unit.

 

[avvidclif]

Do you have a vent in the bedroom? If so remove the cover and I think you will find the ducts are there but blocked off. That's the way my Crossroads 5ers were. Remove the vent, install a ducted unit and remove the blocks. That's the simple version. Remember the ducts do not provide return air, that is on the unit itself. The output is routed into the ducts. The main Ac gets it's return on it and the same for the bedroom. Either can provide air thru the ducts but each has their own return. That make sense???

If you run the main AC the return is on it but the output is thru the ducts so BR air has to go back to the main AC. Same for running the BR AC, it feeds the ducts but the return is on it. If both are running they both feed the ducts and the air flow is increased but the main draws air from the LR and the BR unit draws air from the BR.

On the older units the biggest advantage to ducted was when it reached temperature the unit shut down. The older non-ducted just cycled the compressor but the noisy fan never shut off. GRRRR. I like to run the main AC at night because all the noise is in the LR but I get cool in the BR.

Heartland could learn from the older Crossroads units as they had one thermostat (dual zone) which controlled 2 AC's, there was a sensor in the LR and one in the BR and each could be set independently. My current Cyclone has 3 AC's and 3 thermostats. 2 AC's are ducted (main and BR) and each has it's own thermostat one in LR and one in BR. The third is a non-ducted with it's thermostat next to the main thermostat. The third Ac is 5' from the main unit..... Weird system.

My explanation may not be the greatest so ask any questions.