Our 40'er has 1 a/c and 1 vent with a fan in the bathroom. After this warm weekend we need a 2nd a/c. How many have done this add on is it? Cost? I see the a/c that matches ours is about $650. Where to buy? Anything else you guys can throw at me.

One vent in a 40 footer? Wow. I'd suggest 3 fantastic fan vents.

If your TH was prewired for a second AC, it is relatively easy to remote the vent and install the AC. If you do not have a prewire, look at your breaker box to see if you have additional circuit space and then figure out how you will fish or route dedicated AC power to that location.

Is your rig 50amp? If so check the panel and see if there is a breaker marked 2nd AC. You may be able to add a 2nd AC on a 30amp system but you will not be able to run both AC's at the same time. Running two AC's at the same time on a 30amp system would overload your electrical system... Adding a second AC when not prewired would be a RPITA!

I just added a 2nd AC to my Keystone 3712 in the bedroom. The company that did the installation which is from Starke FL. did not put the second ac on the another 30 amp breaker and it kept tripping the 30 amp breaker when you ran both ACs I called the company in Starke Fl to come out and wire the AC install correctly and they have an attitude problem. I make a mistake in chosing this company to work on my AC install. Learned another lesson, ask more questions about what there certifications are, do they have proper licenses, etc. The man that did installation did good job and even mentioned he should check for correct breaker placement. Got busy, in a hurry and left without correcting. Called for them to come back out and the owner? came out with attitude and when asked basic electric opinions he felt challenged I guess and I told him I did not want anyone working on my TH that was not qualified. He left in a huff. So I guess the answer is when the second ac works it works fine you just make sure as stated earlier they do not put both ac on same 30 amp breaker. Sorry for a bit of a rant but I am becoming more worried about how easy it is for people to buy off internet and become technical experts. I paid close to $1000 for 13.5K ac with install. Sorry for rant, hope this info helps next person. Thanks

Stude55: Is the 30A breaker you're talking about the MAIN 30A breaker or a sub-breaker in the panel? If the latter, you shouldn't even have ONE AC on a 30A breaker - 15 or 20A max.

Adding a/c and other roof vents | Good Sam Community

Lwiddis
Explorer II
Jun 17, 2017
One vent in a 40 footer? Wow. I'd suggest 3 fantastic fan vents.
Bedlam
Moderator
Jun 17, 2017
If your TH was prewired for a second AC, it is relatively easy to remote the vent and install the AC. If you do not have a prewire, look at your breaker box to see if you have additional circuit space and then figure out how you will fish or route dedicated AC power to that location.
1L243
Explorer II
Jun 18, 2017
Is your rig 50amp? If so check the panel and see if there is a breaker marked 2nd AC.

You may be able to add a 2nd AC on a 30amp system but you will not be able to run both AC's at the same time. Running two AC's at the same time on a 30amp system would overload your electrical system... Adding a second AC when not prewired would be a RPITA!
Stude55Dog
Explorer
Jun 18, 2017
I just added a 2nd AC to my Keystone 3712 in the bedroom. The company that did the installation which is from Starke FL. did not put the second ac on the another 30 amp breaker and it kept tripping the 30 amp breaker when you ran both ACs I called the company in Starke Fl to come out and wire the AC install correctly and they have an attitude problem. I make a mistake in chosing this company to work on my AC install. Learned another lesson, ask more questions about what there certifications are, do they have proper licenses, etc. The man that did installation did good job and even mentioned he should check for correct breaker placement. Got busy, in a hurry and left without correcting. Called for them to come back out and the owner? came out with attitude and when asked basic electric opinions he felt challenged I guess and I told him I did not want anyone working on my TH that was not qualified. He left in a huff. So I guess the answer is when the second ac works it works fine you just make sure as stated earlier they do not put both ac on same 30 amp breaker. Sorry for a bit of a rant but I am becoming more worried about how easy it is for people to buy off internet and become technical experts. I paid close to $1000 for 13.5K ac with install. Sorry for rant, hope this info helps next person. Thanks
joebedford
Nomad II
Jun 18, 2017
Stude55: Is the 30A breaker you're talking about the MAIN 30A breaker or a sub-breaker in the panel? If the latter, you shouldn't even have ONE AC on a 30A breaker - 15 or 20A max.
sin_cal_hd
Explorer
Jun 18, 2017
We have 50 amp. I doubt the rv is pre-wired for 2nd or even a 3rd a/c. I diffently want a 2nd in the garage and put a vent fan in the bunk house.
1L243
Explorer II
Jun 18, 2017
sin cal hd wrote:
We have 50 amp. I doubt the rv is pre-wired for 2nd or even a 3rd a/c. I differently want a 2nd in the garage and put a vent fan in the bunk house.

Don't assume.. The only reason for 50 amp is for a second AC. Check the breaker panel for a breaker marked 2nd AC. Remove the inside vent moldings in the garage and bedroom to see if there is a prewired electrical box there.

If your not prewired and since you have 50amp adding a non ducted AC to the Garage vent would be easy if you have access to run wire to the breaker box..
joebedford
Nomad II
Jun 18, 2017
sin cal hd wrote:
We have 50 amp. I doubt the rv is pre-wired for 2nd or even a 3rd a/c.
With 50A it probably IS pre-wired.

I want to add a third a/c but my breaker panel is full so I'll probably run a heavy extension cord to a 20A receptacle on the power post and avoid wiring it into the rv at all.
sin_cal_hd
Explorer
Jun 18, 2017
1L243 wrote:
sin cal hd wrote:
We have 50 amp. I doubt the rv is pre-wired for 2nd or even a 3rd a/c. I differently want a 2nd in the garage and put a vent fan in the bunk house.

Don't assume.. The only reason for 50 amp is for a second AC. Check the breaker panel for a breaker marked 2nd AC. Remove the inside vent moldings in the garage and bedroom to see if there is a prewired electrical box there.

If your not prewired and since you have 50amp adding a non ducted AC to the Garage vent would be easy if you have access to run wire to the breaker box..

I don't have a vent in garage at all.
Running wire to the panel is the biggest issue I see. Plus cutting a whole in the roof of the garage.
1L243
Explorer II
Jun 18, 2017
sin cal hd wrote:
1L243 wrote:
sin cal hd wrote:
We have 50 amp. I doubt the rv is pre-wired for 2nd or even a 3rd a/c. I differently want a 2nd in the garage and put a vent fan in the bunk house.

Don't assume.. The only reason for 50 amp is for a second AC. Check the breaker panel for a breaker marked 2nd AC. Remove the inside vent moldings in the garage and bedroom to see if there is a prewired electrical box there.

If your not prewired and since you have 50amp adding a non ducted AC to the Garage vent would be easy if you have access to run wire to the breaker box..

I don't have a vent in garage at all.
Running wire to the panel is the biggest issue I see. Plus cutting a whole in the roof of the garage.

How about bedroom you got a vent in there?

Without a vent it even becomes harder. besides cutting a hole in the roof you have to block or frame the hole.

I added a second AC to my last Toy Hauler but the Garage was prewired so was easy. Two other toy haulers I had before that one I used a portable AC and vented it out a side vent in the garage and plugged it into the power pedestal separate from the 30amp plug.